bims-metlip 2024-03-31 papers

bims-metlip

Biomed News

on Methods and protocols in metabolomics and lipidomics

Issue of 2024–03–31
37 papers selected by
Sofia Costa, Matterworks

Development and validation of an LC-MS/MS method for quantifying diamorphine and its major metabolites 6-monoacetylmorphine, morphine, morphine-3-glucuronide, and morphine-6-glucuronide in human plasma.
Label-Free Quantitation of Endogenous Peptides.
Simultaneous Determination of One-Carbon Folate Metabolites and One-Carbon-Related Amino Acids in Biological Samples Using a UHPLC-MS/MS Method.
Isomers-oriented separation of forty-five plasma bile acids with liquid chromatography-tandem mass spectrometry.
Matrix- and Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Methods for Urological Cancer Biomarker Discovery-Metabolomics and Lipidomics Approaches.
An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of primidone in human serum and plasma.
Development of a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry for human urine (RaDPi-U).
A solid-liquid microextraction approach from a spot in an adsorbent layer of a chromatographic plate.
Analysis of vitamin D and its metabolites in biological samples - Part II: Optimization of a sample preparation method for liver tissue.
Applications of Liquid Chromatography-Tandem Mass Spectrometry in Natural Products Research: Tropane Alkaloids as a Case Study.
An efficient LC-QTOF-mass spectrometry method for monitoring nal-trexone compliance in urine of opioid-dependent subjects.
Simultaneous determination of 11 oral targeted antineoplastic drugs and 2 active metabolites by LC-MS/MS in human plasma and its application to therapeutic drug monitoring in cancer patients.
Assessment of pheniramine in alternative biological matrices by liquid chromatography tandem mass spectrometry.
[Determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry].
Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping.
Quantification of Trimethylamine-N-Oxide and Trimethylamine in Fish Oils for Human Consumption.
A Chiral-LC-MS Method for the Simultaneous Quantification of Short-Chain Fatty Acids and D/L-Lactate in the Ruminal Fluid of Dairy Cows.
Development and validation of an LC-MS/MS method for quantifying NAD+ and related metabolites in mice sciatic nerves and its application to a nerve injury animal model.
An LC-MS/MS method for the determination of drugs of abuse included THC-COOH, EtG, and NPS, using a single hair extraction sample.
Lipid Wizard: Analysis Software for Comprehensive Two-Dimensional Liquid Chromatography-Mass Spectrometry-Based Lipid Profiling.
A review of analytical parameters in 'rapid' liquid chromatographic methods for bioanalysis: Can we do better?
SpectiCal: m/z Calibration of MS2 Peptide Spectra Using Known Low Mass Ions.
Derivatization of carboxylic groups prior to their LC analysis - A review.
Mass spectrometry imaging protocol for spatial mapping of lipids, N-glycans and peptides in murine lung tissue.
Multiple ion isolation and accumulation events for selective chemical noise reduction and dynamic range enhancement in MALDI imaging mass spectrometry.
A high-throughput method for the determination of 14 UV-filters in human plasma by LC-MS/MS: Minimize interferences from proteins and phospholipids in the matrix.
Tandem Mass Spectrometry across Platforms.
Dispersive Solid-Phase Extraction and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry-A Rapid and Accurate Method for Detecting 10 Macrolide Residues in Aquatic Products.
Comprehensive LC-MS/MS Analysis of Nitrogen-Related Plant Metabolites.
Simultaneous Determination of D and L Enantiomers of 2-Hydroxyglutarate by UHPLC-MS/MS Method in Human Biological Fluids and its Clinical Application.
Detection of Anatoxins in Human Urine by Liquid Chromatography Triple Quadrupole Mass Spectrometry and ELISA.
From sound check to encore: A journey through high-resolution mass spectrometry-based food analyses and metabolomics.
Magnetic Particle Spray Mass Spectrometry.
Development of a simple screening method for analyzing cereulide toxin in fried rice using liquid chromatography-tandem mass spectrometry.
LC-MS/MS analysis of 11-nor-9-carboxy-hexahydrocannabinol (HHC-COOH) and 11-hydroxy-hexahydrocannabinol (HHC-OH) for verification of hexahydrocannabinol (HHC) intake.
Two-dimensional liquid chromatography with reversed phase in both dimensions: A review.
Development and Application of a Multidimensional Database for the Detection of Quaternary Ammonium Compounds and Their Phase I Hepatic Metabolites in Humans.

J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Mar 25. pii: S1570-0232(24)00112-0. [Epub ahead of print]1237 124104

Development and validation of an LC-MS/MS method for quantifying diamorphine and its major metabolites 6-monoacetylmorphine, morphine, morphine-3-glucuronide, and morphine-6-glucuronide in human plasma.

Jan Thomann, Severin B Vogt, Adrian Guessoum, Maximilian Meyer, Marc Vogel, Matthias E Liechti, Dino Luethi, Urs Duthaler.

  Diamorphine, commonly known as heroin, is a semi-synthetic opioid analgesic. In the context of heroin-assisted treatment for opioid-dependent patients, diamorphine is mostly administered intravenously. However, recent attention has shifted towards intranasal administration as a better-tolerated alternative to the intravenous route. Here, we developed and validated a rapid bioanalytical method for the simultaneous quantification of diamorphine and its major metabolites 6-monoacetylmorphine, morphine, morphine-3-glucuronide, and morphine-6-glucuronide in human plasma using liquid chromatography-tandem mass spectrometry (LC-MS/MS). A straightforward protein precipitation extraction step was used for sample preparation. Chromatographic analyte separation was achieved using a Kinetex EVO C18 analytical column and a mobile phase gradient comprising an aqueous solution of ammonium hydrogen carbonate and methanol supplied with formic acid. Employing positive electrospray ionization and scheduled multiple reaction monitoring, we established a quantification range of 1-1,000 ng/mL for all analytes. Our validation results demonstrate a mean intra-assay accuracy of 91-106% and an intra-assay precision (CV) between 2 and 9% for all analytes and over three validation runs. The method exhibits a high extraction recovery (> 87%) and a negligible matrix effect (99-125%). Furthermore, no interferences with endogenous plasma compounds were detected. Lastly, we applied the method to assess the plasma concentrations of an opioid-dependent patient after the intranasal administration of diamorphine in a clinical study. In summary, we have successfully developed a rapid, highly reliable, and straightforward bioanalytical method for quantifying diamorphine and its metabolites in low amounts of clinical plasma samples.

Keywords:  Diamorphine; LC-MS/MS; Metabolites; Method development; Method validation; Pharmacokinetics

DOI:  https://doi.org/10.1016/j.jchromb.2024.124104
Methods Mol Biol. 2024 ;2758 125-150

Label-Free Quantitation of Endogenous Peptides.

Md Shadman Ridwan Abid, Haowen Qiu, James W Checco.

  Liquid chromatography-mass spectrometry (LC-MS)-based peptidomics methods allow for the detection and identification of many peptides in a complex biological mixture in an untargeted manner. Quantitative peptidomics approaches allow for comparisons of peptide abundance between different samples, allowing one to draw conclusions about peptide differences as a function of experimental treatment or physiology. While stable isotope labeling is a powerful approach for quantitative proteomics and peptidomics, advances in mass spectrometry instrumentation and analysis tools have allowed label-free methods to gain popularity in recent years. In a general label-free quantitative peptidomics experiment, peak intensity information for each peptide is compared across multiple LC-MS runs. Here, we outline a general approach for label-free quantitative peptidomics experiments, including steps for sample preparation, LC-MS data acquisition, data processing, and statistical analysis. Special attention is paid to address run-to-run variability, which can lead to several major problems in label-free experiments. Overall, our method provides researchers with a framework for the development of their own quantitative peptidomics workflows applicable to quantitation of peptides from a wide variety of different biological sources.

Keywords:  LC-MS; Label-free; Mass spectrometry; Missing values; Peptides; Peptidomics; Pooled QC samples; Run-to-run variability

DOI:  https://doi.org/10.1007/978-1-0716-3646-6_7
Int J Mol Sci. 2024 Mar 19. pii: 3458. [Epub ahead of print]25(6):

Simultaneous Determination of One-Carbon Folate Metabolites and One-Carbon-Related Amino Acids in Biological Samples Using a UHPLC-MS/MS Method.

Yi Ling, Mei Tan, Xiaoyun Wang, Ziyi Meng, Xiaodong Quan, Hosahalli Ramaswamy, Chao Wang.

  One-carbon folate metabolites and one-carbon-related amino acids play an important role in human physiology, and their detection in biological samples is essential. However, poor stability as well as low concentrations and occurrence in different species in various biological samples make their quantification very challenging. The aim of this study was to develop a simple, fast, and sensitive ultra-high-performance liquid chromatography MS/MS (UHPLC-MS/MS) method for the simultaneous quantification of various one-carbon folate metabolites (folic acid (FA), tetrahydrofolic acid (THF), p-aminobenzoyl-L-glutamic acid (pABG), 5-formyltetrahydrofolic acid (5-CHOTHF), 5-methyltetrahydrofolic acid (5-CH3THF), 10-formylfolic acid (10-CHOFA), 5,10-methenyl-5,6,7,8-tetrahydrofolic acid (5,10-CH+-THF), and 4-α-hydroxy-5-methyltetrahydrofolate (hmTHF)) and one-carbon-related amino acids (homocysteine (Hcy), methionine (Met), S-ade-L-homocysteine (SAH), and S-ade-L-methionine (SAM)). The method was standardized and validated by determining the selectivity, carryover, limits of detection, limits of quantitation, linearity, precision, accuracy, recovery, and matrix effects. The extraction methods were optimized with respect to several factors: protease-amylase treatment on embryos, deconjugation time, methanol precipitation, and proteins' isoelectric point precipitation on the folate recovery. Ten one-carbon folate metabolites and four one-carbon-related amino acids were detected using the UHPLC-MS/MS technique in various biological samples. The measured values of folate in human plasma, serum, and whole blood (WB) lay within the concentration range for normal donors. The contents of each analyte in mouse plasma were as follows: pABG (864.0 nmol/L), 5-CH3THF (202.2 nmol/L), hmTHF (122.2 nmol/L), Met (8.63 μmol/L), and SAH (0.06 μmol/L). The concentration of each analyte in mouse embryos were as follows: SAM (1.09 μg/g), SAH (0.13 μg/g), Met (16.5 μg/g), 5,10-CH+THF (74.3 ng/g), pABG (20.6 ng/g), and 5-CH3THF (185.4 ng/g). A simple and rapid sample preparation and UHPLC-MS/MS method was developed and validated for the simultaneous determination of the one-carbon-related folate metabolites and one-carbon-related amino acids in different biological samples.

Keywords:  UHPLC–MS/MS; amino acids; biological samples; folate

DOI:  https://doi.org/10.3390/ijms25063458
J Chromatogr A. 2024 Mar 20. pii: S0021-9673(24)00200-0. [Epub ahead of print]1721 464827

Isomers-oriented separation of forty-five plasma bile acids with liquid chromatography-tandem mass spectrometry.

Lei Zhang, Xu Liu, Tenghui Jin, Jing Dong, Xiaodong Li, Youyi Zhang, Dongyang Liu.

  Some bile acids (BAs) were considered as biomarkers or have therapeutical effect on metabolic diseases. However, due to the existence of isomers and limitations in sensitivity, simultaneous quantification of multiple BAs remains a challenge. The aim of this study is to establish an accurate and sensitive method for the determination of multiple BAs with similar polarity. A LC-MS/MS analytical method capable of quantifying forty-five BAs simultaneously using nine stable isotope internal standards was developed and fully validated based on key isomers-oriented separation strategy. The method was further applied to analyze plasma samples to describe the dynamic profile of BAs after high glucose intake. The chromatography and mass spectrum conditions were optimized to enable the accurate quantification of forty-five BAs, while ensuring the lower limit of quantification between 0.05-10 ng/mL. The results of system suitability, linearity, dilution integrity, accuracy and precision demonstrated the good quantitative capacity and robustness of the method. A total of thirty-five BAs were quantified in plasma samples from twelve healthy Chinese individuals. The established method featured superior sensitivity and better separation efficiency compared to previous studies. Meanwhile, BAs exhibited correlations with glucose and insulin, suggesting their potential as biomarkers for metabolic disorders.

Keywords:  Bile acids; Isomers-oriented separation; LC-MS/MS; Metabolic diseases; Method validation

DOI:  https://doi.org/10.1016/j.chroma.2024.464827
Metabolites. 2024 Mar 20. pii: 173. [Epub ahead of print]14(3):

Matrix- and Surface-Assisted Laser Desorption/Ionization Mass Spectrometry Methods for Urological Cancer Biomarker Discovery-Metabolomics and Lipidomics Approaches.

Adrian Arendowski.

  Urinary tract cancers, including those of the bladder, the kidneys, and the prostate, represent over 12% of all cancers, with significant global incidence and mortality rates. The continuous challenge that these cancers present necessitates the development of innovative diagnostic and prognostic methods, such as identifying specific biomarkers indicative of cancer. Biomarkers, which can be genes, proteins, metabolites, or lipids, are vital for various clinical purposes including early detection and prognosis. Mass spectrometry (MS), particularly soft ionization techniques such as electrospray ionization (ESI) and laser desorption/ionization (LDI), has emerged as a key tool in metabolic profiling for biomarker discovery, due to its high resolution, sensitivity, and ability to analyze complex biological samples. Among the LDI techniques, matrix-assisted laser desorption/ionization (MALDI) and surface-assisted laser desorption/ionization (SALDI) should be mentioned. While MALDI methodology, which uses organic compounds as matrices, is effective for larger molecules, SALDI, based on the various types of nanoparticles and nanostructures, is preferred for smaller metabolites and lipids due to its reduced spectral interference. This study highlights the application of LDI techniques, along with mass spectrometry imaging (MSI), in identifying potential metabolic and lipid biomarkers for urological cancers, focusing on the most common bladder, kidney, and prostate cancers.

Keywords:  biomarkers; bladder cancer; kidney cancer; lipids; mass spectrometry; matrix-assisted laser desorption/ionization; metabolites; prostate cancer; surface-assisted laser desorption/ionization

DOI:  https://doi.org/10.3390/metabo14030173
Clin Chem Lab Med. 2024 Mar 29.

An isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based candidate reference measurement procedure (RMP) for the quantification of primidone in human serum and plasma.

Tobias Schierscher, Linda Salzmann, Neeraj Singh, Vanessa Fischer, Anja Kobel, Friederike Bauland, Andrea Geistanger, Lorenz Risch, Christian Geletneky, Christoph Seger, Judith Taibon.

   OBJECTIVES: Primidone is an anticonvulsive drug used in the treatment of epilepsy and essential tremor. It offers beneficial effects in controlling seizures, but its usage is also associated with possible side effects. To ensure optimal therapy, it is crucial to measure its concentration through accurate quantification methods. Therefore, our main goal was to develop and validate a new reference measurement procedure (RMP) for accurately measuring primidone levels in human serum and plasma.
METHODS: In our study, we focused on the separation of primidone from both known and unknown interferences using a C18 column. To achieve accurate sample preparation, we developed a protocol involving protein precipitation followed by a high dilution step. The validation of the assay and determination of measurement uncertainty were carried out following guidelines from organizations such as the Clinical and Laboratory Standards Institute, the International Conference on Harmonization, and the Guide to the Expression of Uncertainty in Measurement. These rigorous validation processes ensure the reliability and accuracy of our method for quantifying primidone levels in human serum and plasma samples.
RESULTS: The RMP was shown to be highly selective and specific, with no evidence of matrix interference. It can be used to quantify primidone in the range of 0.150-30.0 μg/mL. Intermediate precision was less than 4.0 %, and repeatability CV ranged from 1.0 to 3.3 % across all concentration levels. The relative mean bias ranged from 0.1 to 3.9 % for native serum levels, and from -2.6 to 2.8 % for lithium-heparin plasma levels. The measurement uncertainties for single measurements and target value assignment were 1.5-4.1 % and 0.9-1.0 %, respectively.
CONCLUSIONS: In this study, we introduce an innovative LC-MS/MS-based candidate RMP specifically designed for primidone in human serum and plasma. Our RMP offers a traceable platform, facilitating the standardization of routine assays and enabling the evaluation of clinically relevant samples. With this novel approach, we aim to enhance the accuracy and reliability of primidone measurements, ultimately benefiting the field of clinical research and patient care.

Keywords:  ID-LC-MS/MS; primidone; qNMR; reference measurement procedure; standardization; traceability

DOI:  https://doi.org/10.1515/cclm-2023-1032
Anal Bioanal Chem. 2024 Apr;416(10): 2503-2513

Development of a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry for human urine (RaDPi-U).

Kazuaki Hisatsune, Tasuku Murata, Masaru Taniguchi, Tomomi Asano, Koretsugu Ogata, Akira Iguchi, Kei Zaitsu.

  Drug screening tests are mandatory in the search for drugs in forensic biological samples, and immunological methods and mass spectrometry (e.g., gas chromatography-mass spectrometry and liquid chromatography-tandem mass spectrometry) are commonly used for that purpose. However, these methods have some drawbacks, and developing new screening methods is required. In this study, we develop a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry (PESI-MS/MS), which is an ambient ionization mass spectrometry method, for human urine, named RaDPi-U. RaDPi-U is carried out in three steps: (1) mixing urine with internal standard (IS) solution and ethanol, followed by vortexing; (2) pipetting the mixture onto a sample plate for PESI; and (3) rapid-fire analysis by PESI-MS/MS. RaDPi-U targets 40 forensically important drugs, which include illegal drugs, hypnotics, and psychoactive substances. The analytical results were obtained within 3 min because of the above-mentioned simple workflow of RaDPi-U. The calibration curves of each analyte were constructed using the IS method, and they were quantitatively valid, resulting in good linearity (0.972-0.999) with a satisfactory lower limit of detection and lower limit of quantitation (0.01-7.1 ng/mL and 0.02-21 ng/mL, respectively). Further, both trueness and precisions were 28% or less, demonstrating the high reliability and repeatability of the method. Finally, we applied RaDPi-U to three postmortem urine specimens and successfully detected different drugs in each urine sample. The practicality of the method is proven, and RaDPi-U will be a strong tool as a rapid-fire drug screening method not only in forensic toxicology but also in clinical toxicology.

Keywords:  Ambient ionization mass spectrometry; Drug screening test; Probe electrospray ionization tandem mass spectrometry; Urine

DOI:  https://doi.org/10.1007/s00216-024-05215-x
J Chromatogr A. 2024 Mar 18. pii: S0021-9673(24)00199-7. [Epub ahead of print]1721 464826

A solid-liquid microextraction approach from a spot in an adsorbent layer of a chromatographic plate.

Rafał Gajos, Anna Klimek-Turek, Tadeusz H Dzido.

  A new approach to extracting substances from a spot on a chromatographic plate for subsequent liquid chromatography-mass spectrometry analysis is described. This method involves extraction in a solid phase (an adsorbent layer of a chromatographic plate) - a liquid system using a simple device. For a single extraction of six selected coccidiostats from the adsorbent layer on the chromatographic plate with silica gel, 50 µL of methanol was used for 5 min. The data from the extraction experiments and liquid chromatography-mass spectrometry measurements demonstrated a good correlation between the ratio of the peak areas of the coccidiostats to the internal standard and the concentration of the substances in the range of two orders of magnitude. The coefficients of determination for the mentioned correlations range from 0.962 to 0.999. Moreover, the repeatability and reproducibility, expressed as the percentage values of relative standard deviation, do not exceed 7.5 % for any of the coccidiostats.

Keywords:  Coccidiostats extraction; Extraction device; HPTLC-MS Coupling; LC-MS; Sample preparation

DOI:  https://doi.org/10.1016/j.chroma.2024.464826
J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Mar 11. pii: S1570-0232(24)00096-5. [Epub ahead of print]1237 124088

Analysis of vitamin D and its metabolites in biological samples - Part II: Optimization of a sample preparation method for liver tissue.

Veronika Pilařová, Bárbara Socas-Rodríguez, Lucie Nováková, Cecilia Holm, Margareta Sandahl, Charlotta Turner.

  Extraction of vitamin D, including its hydroxylated and esterified metabolites, from soft tissues such as the liver is challenging due to the lipophilic character of matrix and analytes that are expected in very low concentration levels. In this study, we aimed at the optimization of two-step extraction using solid-liquid extraction as the first step, followed by solid-phase extraction. Various solvents, including ethanol, acetonitrile, methanol, acetone, heptane, and heptane with isopropanol, were investigated to isolate vitamin D compounds from liver tissue in the first step. Acetone was finally selected as the most suitable solvent for the solid-liquid extraction, with the highest recovery in the range of 67 - 98% for polar hydroxylated forms and 3 - 28% for lipophilic vitamin D and esters. Two solid phase extraction (SPE) based on the (i) "bind and elute strategy" and (ii) "removal strategy" using hydrophilic-lipophilic balanced SPE sorbent were optimized as a proceeding step for acetone extracts to increase the method selectivity. Finally, two optimized methods, combining solid-liquid extraction and individual SPE strategy, were examined in terms of sensitivity, recovery, matrix effect, accuracy, and precision. The limits of quantification were in the range of 1 - 10 ng/mL and 3 - 20 ng/mL analyzed by ultra-high performance supercritical fluid chromatography and ultra-high performance liquid chromatography hyphenated a with tandem mass spectrometer, respectively. The absolute recovery determined for the "bind and elute strategy" protocol was in the range of 3 - 24 %. Nevertheless, this method was free of matrix effects, which were determined to be in the 73 - 120 % range. On the contrary, the "removal strategy" approach provided higher recovery values for all compounds (47 - 123 %), but the results for nonpolar vitamin D and esters were strongly affected by signal suppression (matrix effects 3 - 51 %). Both methods fulfilled the criteria for accuracy and precision requested by the European Medicine Agency Guideline on Bioanalysis. "Removal strategy" SPE with decreased manual intervention and lower solvent consumption was finally applied to mouse liver tissue to determine vitamin D and its hydroxylated and esterified metabolites for the first time. The results, i.e., vitamin D esters detected in liver tissue, supported the notion that esters of vitamin D can be stored in lipophilic tissues to release vitamin D.

Keywords:  Acetone; Mass spectrometry; Solid phase extraction; Solid–liquid extraction; Ultra-high performance supercritical fluid chromatography; vitamin D esters

DOI:  https://doi.org/10.1016/j.jchromb.2024.124088
J Vis Exp. 2024 Mar 08.

Applications of Liquid Chromatography-Tandem Mass Spectrometry in Natural Products Research: Tropane Alkaloids as a Case Study.

Maris A Cinelli, Jill Cline, Tyler Watson.

Although many drugs utilized today are synthetic in origin, natural products still provide a rich source of novel chemical diversity and bioactivity, and can yield promising leads for resistant or emerging diseases. The challenge, however, is twofold: not only must researchers find natural products and elucidate their structures, but they must also identify what is worth isolating and assaying (and what is already known - a process known as dereplication). With the advent of modern analytical instrumentation, the pace of natural product discovery and dereplication has accelerated. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has become an especially valuable technique for identifying and classifying chemical structures. Tropane alkaloids (TAs) are plant-derived compounds of great medicinal and toxicological significance. In this study, we developed an LC-MS/MS-based screening workflow utilizing the multiple MS/MS configurations available on a triple-quadrupole (QQQ) mass spectrometer to annotate and classify TA structures based on their distinct fragmentation patterns. By using a combination of data-dependent (DD) product ion scans, precursor ion scans (PrIS), and neutral loss scans (NLS), we applied this method to TA-rich extracts of the nightshades Datura stramonium and Datura metel. This method is rapid, sensitive, and was successfully employed for both preliminary dereplication of complex TA-containing samples and for the discovery of a novel candidate for isolation, purification (and eventual bioassay).

DOI: https://doi.org/10.3791/66620
J Opioid Manag. 2024 Jan-Feb;20(1):pii: jom.0841. [Epub ahead of print]20(1): 5-9

An efficient LC-QTOF-mass spectrometry method for monitoring nal-trexone compliance in urine of opioid-dependent subjects.

Raka Jain, Piyali Mandal, Sachin Rana.

Naltrexone (NTX) is an orally effective opiate antagonist used in maintenance treatment for opiate dependence. Its utility is limited by the patient's noncompliance. The study aimed to develop an efficient method for the detection of NTX in urine by LC-QTOF-mass spectrometry (MS) and its application to NTX compliance in opioid-dependent subjects. Sample preparation included a dilution step and direct injection to LC-QTOF-MS. Chromatographic separation was achieved with a C-18 column using a mixture of mobile phase 0.1 percent formic acid in water and 0.1 percent formic acid in 95 percent methanol. The calibration curve was linear in the range 1-100 ng/mL with a correlation coefficient higher than 0.996. Precision and accuracy were acceptable, and the recovery efficiency range was 80-85 percent. The current LC-QTOF-MS method is simple, precise, sensitive, and can be used for monitoring NTX compliance among opioid-dependent subjects in a clinical setting.

DOI: https://doi.org/10.5055/jom.0841
J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Mar 26. pii: S1570-0232(24)00108-9. [Epub ahead of print]1237 124100

Simultaneous determination of 11 oral targeted antineoplastic drugs and 2 active metabolites by LC-MS/MS in human plasma and its application to therapeutic drug monitoring in cancer patients.

Jing Zhao, Dongming Yan, Yue Li, Xiaoqing Xu, Fengling Li, Shuang Zhang, Jingyi Jin, Furong Qiu.

  Interindividual exposure differences have been identified in oral targeted antineoplastic drugs (OADs) owing to the pharmacogenetic background of the patients and their susceptibility to multiple factors, resulting in insufficient efficacy or adverse effects. Therapeutic drug monitoring (TDM) can prevent sub-optimal concentrations of OADs and improve their clinical treatment. This study aimed to develop and validate an LC-MS/MS method for the simultaneous quantification of 11 OADs (gefitinib, imatinib, lenvatinib, regorafenib, everolimus, osimertinib, sunitinib, tamoxifen, lapatinib, fruquintinib and sorafenib) and 2 active metabolites (N-desethyl sunitinib and Z-endoxifen) in human plasma. Protein precipitation was used to extract OADs from the plasma samples. Chromatographic separation was performed using an Eclipse XDB-C18 (4.6 × 150 mm, 5 μm) column with a gradient elution of the mobile phase composed of 2 mM ammonium acetate with 0.1 % formic acid in water (solvent A) and methanol (solvent B) at a flow rate of 0.8 mL/min. Mass analysis was performed using positive ion mode electrospray ionization in multiple-reaction monitoring mode. The developed method was validated following FDA bioanalytical guidelines. The calibration curves were linear over the range of 2-400 ng/mL for gefitinib, imatinib, lenvatinib, regorafenib, and everolimus; 1-200 ng/mL for osimertinib, sunitinib, N-desethyl sunitinib, tamoxifen, and Z-endoxifen; and 5-1000 ng/mL for lapatinib, fruquintinib, and sorafenib, with all coefficients of correlation above 0.99. The intra- and inter-day imprecision was below 12.81 %. This method was successfully applied to the routine TDM of gefitinib, lenvatinib, regorafenib, osimertinib, fruquintinib, and sorafenib to optimize the dosage regimens.

Keywords:  Dose optimization; Liquid chromatography-tandem mass spectrometry; Oral targeted antineoplastic drugs; Therapeutic drug monitoring

DOI:  https://doi.org/10.1016/j.jchromb.2024.124100
Forensic Sci Med Pathol. 2024 Mar 26.

Assessment of pheniramine in alternative biological matrices by liquid chromatography tandem mass spectrometry.

Humera Shafi Makhdoom, Ali Imran Abid, Majida Mujahid, Saira Afzal, Kishwar Sultana, Nisar Hussain, Kashif Barkat.

  Pheniramine is an over-the-counter antihistamine drug. Its accessibility and low cost made it more popular among drug abusers in Pakistan. In this study, pheniramine was quantified in both conventional and alternative specimens of twenty chronic drug abusers, aged 16-50 years, who were positive for pheniramine in comprehensive toxicological screening for drugs by gas chromatography with mass spectral detection in positive electron impact mode. Pheniramine was extracted from biological specimens using solid phase extraction and liquid chromatography tandem mass spectrometry was employed for quantification. Chromatographic separation was carried out on a Poroshell120EC-18 (2.1 mm × 50 mm × 2.7 µm) column using water-acetonitrile in formic acid (0.1%) mobile phase in gradient elution mode with 500 μL/min flow rate. Positive electrospray ionization mode and multi-reaction monitoring with ion transitions m/z 241.3 → 195.8 and 167.1 for pheniramine and m/z m/z 247.6 → 173.1 for pheniramine-d6 were employed. The quantification method showed good linear ranges of 2-1000 ng/mL in blood, urine, and oral fluid; 2-1000 ng/mg in hair and 5-1000 ng/mg in nail with ≥ 0.985% coefficient of linearity. The retention time of pheniramine was 3.0 ± 0.1 min. The detection and lower quantification limits were 1 ng/mL and 2 ng/mL for blood, urine, oral fluid and hair whereas 2.5 ng/mg and 5 ng/mg for nail, respectively. Mean extraction recovery and ionization suppression ranged 86.3-95.1% and -4.6 to -14.4% in the studied matrices. Intra-day and inter-day precision were 4.1-9.3% and 2.8-11.2%, respectively. Pheniramine levels in specimens of drug abusers were 23-480 ng/mL in blood, 72-735 ng/mL in urine, 25-379 ng/mL in oral fluid, 10-170 ng/mg in hair and 8-86 ng/mg in nail specimens. Alternative specimens are of utmost significance in clinical and medico-legal cases. In this study, authors compared matrix-matched calibration curves to blood calibration curve and obtained results within ± 10%; thereby justifying the use of blood calibration curve for urine, oral fluid, hair, and nail specimens.

Keywords:  Abuse; Alternative; Conventional; LC-MS/MS; Pheniramine

DOI:  https://doi.org/10.1007/s12024-024-00795-7
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi. 2024 Mar 20. 42(3): 202-205

[Determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry].

X H Chen, Q L Qiu.

  Objective: To establish a method for the determination of two perfluorinated compounds in urine by liquid chromatography-tandem mass spectrometry. Methods: In November 2022, urine samples were extracted by acidic methanol, purified by WAX solid phase extraction column, and eluted with methanol water, then Waters ACQUITY UPLC BEH C18 column (100 mm×2.1 mm, 1.7 μm) was used with 1.0 mmol/L ammonium acetate solution and methanol as mobile phase. The gradient elution was carried out, the detection was carried out by electrospray negative ion multiple response monitoring (MRM) mode, and the quantitative method was internal standard method. Results: Perfluorooctanoic acid and perfluorooctane sulfonic acid had a good linear relationship in the concentration range of 0.5-50.0 μg/L, and the correlation coefficient was >0.999. The limit of detection was 0.017 μg/L, and the limit of quantitation was 0.005 μg/L. The average recoveries were 96.3% and 101.8%, respectively. Days of precision were 3.5%-6.2% and 3.1%-7.4%, respectively, daytime precision were 4.3%-6.8% and 4.7%-8.1%, respectively. Conclusion: The established method of liquid chromatography-tandem mass spectrometry is high sensitivity and accuracy, and is suitable for the determination of perfluorooctanoic acid and perfluorooctane sulfonic acid in human urine.

Keywords:  Chromatography, liquid; Fluorine compounds; Perfluorooctane sulfonic acid (PFOS); Perfluorooctanoic acid (PFOA); Solid phase extraction; Tandem mass spectrometry; Urine

DOI:  https://doi.org/10.3760/cma.j.cn121094-20230217-00047
Biophys Rep. 2023 Dec 31. 9(6): 299-308

Rapid quantification of 50 fatty acids in small amounts of biological samples for population molecular phenotyping.

Pinghui Liu, Qinsheng Chen, Lianglong Zhang, Chengcheng Ren, Biru Shi, Jingxian Zhang, Shuaiyao Wang, Ziliang Chen, Qi Wang, Hui Xie, Qingxia Huang, Huiru Tang.

  Efficient quantification of fatty-acid (FA) composition (fatty-acidome) in biological samples is crucial for understanding physiology and pathophysiology in large population cohorts. Here, we report a rapid GC-FID/MS method for simultaneous quantification of all FAs in numerous biological matrices. Within eight minutes, this method enabled simultaneous quantification of 50 FAs as fatty-acid methyl esters (FAMEs) in femtomole levels following the efficient transformation of FAs in all lipids including FFAs, cholesterol-esters, glycerides, phospholipids and sphingolipids. The method showed satisfactory inter-day and intra-day precision, stability and linearity (R2 > 0.994) within a concentration range of 2-3 orders of magnitude. FAs were then quantified in typical multiple biological matrices including human biofluids (urine, plasma) and cells, animal intestinal content and tissue samples. We also established a quantitative structure-retention relationship (QSRR) for analytes to accurately predict their retention time and aid their reliable identification. We further developed a novel no-additive retention index (NARI) with endogenous FAMEs reducing inter-batch variations to 15 seconds; such NARI performed better than the alkanes-based classical RI, making meta-analysis possible for data obtained from different batches and platforms. Collectively, this provides an inexpensive high-throughput analytical system for quantitative phenotyping of all FAs in 8-minutes multiple biological matrices in large cohort studies of pathophysiological effects.

Keywords:  Fatty-acidomics; High-throughput quantification; No-additive retention index; Structure-retention relationship

DOI:  https://doi.org/10.52601/bpr.2023.230042
Molecules. 2024 Mar 17. pii: 1339. [Epub ahead of print]29(6):

Quantification of Trimethylamine-N-Oxide and Trimethylamine in Fish Oils for Human Consumption.

Dominik Dörfel, Sascha Rohn, Eckard Jantzen.

  Supplementing fish oil is one of the strategies to reduce the risk of cardiovascular disease, the leading cause of death around the world. Contradictorily, fish oil may also contain trimethylamine-N-oxide, a recently emerged risk factor for cardiovascular disease, as well as one of its precursors, trimethylamine. A method suitable for routine quantification of trimethylamine-N-oxide and trimethylamine in fish oil with a quick and easy liquid extraction without derivatization has been developed. Liquid chromatography with tandem mass spectrometry detection was employed along with a zwitterionic hydrophilic interaction liquid chromatography column and a gradient elution with eluents containing 50 mmol/L of ammonium formate. An internal standard (triethylamine) was used for quantification by mass spectrometry with an external calibration. The assay proved high linearity in the ranges of 10 to 100 ng/mL and 100 to 1000 ng/mL for trimethylamine-N-oxide and trimethylamine, respectively. The lowest limit of quantification was determined to be 100 µg/kg for trimethylamine and 10 µg/kg for trimethylamine-N-oxide, with the limit of detection at 5 µg/kg and 0.25 µg/kg, respectively. Accuracy ranged from 106-119%. Precision was below 7% the relative standard deviation for both analytes. The method was successfully applied for the determination of trimethylamine-N-oxide and trimethylamine contents in nine commercially available liquid fish oils and three commercially available fish oil capsules, showing that trimethylamine and trimethylamine-N-oxide are not present in highly refined fish oils.

Keywords:  HILIC-MS/MS; cardiovascular disease; fish oil; liquid extraction; trimethylamine; trimethylamine-N-oxide

DOI:  https://doi.org/10.3390/molecules29061339
Molecules. 2024 Mar 21. pii: 1398. [Epub ahead of print]29(6):

A Chiral-LC-MS Method for the Simultaneous Quantification of Short-Chain Fatty Acids and D/L-Lactate in the Ruminal Fluid of Dairy Cows.

Zhiqian Liu, S Richard O Williams, Joe L Jacobs, Aodan S O Neachtain, Simone Rochfort.

  Short-chain fatty acids (SCFA) and lactate in ruminal fluid are products resulting from the microbial fermentation of substrates and can be used to reflect the composition and activity of the ruminal microbiome. Determination of SCFA and D-/L-lactate in ruminal fluid currently requires two separate protocols, which is time-consuming and costly. In this study, we have optimised and validated a simple and unified 3-nitrophenylhydrazine (3-NPH) derivatisation protocol and a 20 min chiral-LC-MS method for the simultaneous quantification of all SCFA and D- and L-lactate in ruminal fluid. This method, which requires no sample pretreatment or purification shows adequate sensitivity (limit of detection (LOD): 0.01 µg/mL), satisfactory accuracy (recovery: 88-103%), and excellent reproducibility (relative standard deviation (RSD) for repeated analyses < 3% for most analytes). The application of this method to a cohort of 24 animals allowed us to reveal a large inter-cow variation in ruminal SCFA and lactate level, the concentration range for each species, the widespread correlation between different SCFA, and the strong correlation between D- and L-lactate.

Keywords:  D-lactate; L-lactate; liquid chromatography–mass spectrometry; ruminal fluid; short-chain fatty acids

DOI:  https://doi.org/10.3390/molecules29061398
J Chromatogr A. 2024 Mar 15. pii: S0021-9673(24)00194-8. [Epub ahead of print]1721 464821

Development and validation of an LC-MS/MS method for quantifying NAD+ and related metabolites in mice sciatic nerves and its application to a nerve injury animal model.

Yongfen Ma, Li Deng, Zhenxia Du.

  Recent studies highlight the pivotal roles of Nicotinamide adenine dinucleotide (NAD+) and its metabolites in aging and neurodegeneration. Accurate quantification of NAD+ and its metabolite levels in cells or tissues is crucial for advancing biochemical research and interventions targeting aging and neurodegenerative diseases. This study presents an accurate, precise, and rapid LC-MS/MS method using a surrogate matrix to quantify endogenous substances NAD+, nicotinamide mononucleotide (NMN), nicotinamide (NAM), adenosine diphosphate ribose (ADPR), and cyclic adenosine diphosphate ribose (cADPR) concentrations in mice sciatic nerves. Considering the properties of the phosphate groups in the analytes, the column and mobile phase were systematically optimized. These five polar analytes exhibited excellent analytical performance and baseline separation within 5 min on an Atlantis Premier BEH C18 AX column, with methylene phosphonic acid as a mobile phase additive. Enhanced sensitivity addressed the challenges posed by the small sample size of mice sciatic nerve and low NMN and cADPR detection. The method was fully validated, with linear correlation coefficients exceeding 0.992, precision (%relative standard deviation, RSD) values within 8.8%, and accuracy values between 92.2% and 107.3%, suggesting good reproducibility. Analytical recoveries in spiked and diluted matrix ranged from 87.8% to 104.7%, indicating the suitability of water as a surrogate matrix. Application of the method to quantify NAD+ and its metabolite levels in normal and injured mice sciatic nerve identified cADPR as a sensitive biomarker in the nerve injury model. This method is anticipated to deepen our understanding of the connections between NAD+ and its metabolites in health and disease, potentially improving diagnoses of various neurological disorders and aiding drug development for aging and neurodegenerative diseases.

Keywords:  LC-MS/MS; NAD(+); Neurodegeneration; Sciatic nerve; cADPR

DOI:  https://doi.org/10.1016/j.chroma.2024.464821
Drug Test Anal. 2024 Mar 26.

An LC-MS/MS method for the determination of drugs of abuse included THC-COOH, EtG, and NPS, using a single hair extraction sample.

Valentina Longo, Giulia Stocchero, Manuela Lucchiari, Giovanni Michele Marchio, Flora Donini, Francesco Ingenito, Lucia Bertoldi, Lucia Pecoraro, Adriano Anesi, Donata Favretto.

  Hair analysis plays an important role in the determination of drugs of abuse in both forensic and clinical toxicology investigations. The analysis of different substances often requires the use of different sample preparation methods, thereby increasing the amount of hair sample and time required. In the present study, a fast method involving a combination of a single 25 mg hair extraction procedure and four liquid chromatography-tandem mass spectrometry methods using the same chromatographic phases and column was developed and validated. The target was the identification and quantification of various commonly abused drugs and their metabolites, including amphetamines, cocaine, opioids, cannabinoids, THC-COOH and EtG, and more than 140 new psychoactive substances, including synthetic cannabinoids, phenethylamines, synthetic opioids, methylphenidate, cathinone, piperidine, and tryptamines.

Keywords:  LC‐MS/MS; drug abuse; hair extraction

DOI:  https://doi.org/10.1002/dta.3675
Anal Chem. 2024 Mar 24.

Lipid Wizard: Analysis Software for Comprehensive Two-Dimensional Liquid Chromatography-Mass Spectrometry-Based Lipid Profiling.

Raobo Xu, Huan Liu, Fang Yuan, Seongho Kim, Irina Kirpich, Craig J McClain, Xiang Zhang.

Lipids play a significant role in life activities and participate in the biological system through different pathways. Although comprehensive two-dimensional liquid chromatography-mass spectrometry (2DLC-MS) has been developed to profile lipid abundance changes, lipid identification and quantification from 2DLC-MS data remain a challenge. We created Lipid Wizard, open-source software for lipid assignment and isotopic peak stripping of the 2DLC-MS data. Lipid Wizard takes the peak list deconvoluted from the 2DLC-MS data as input and assigns each isotopic peak to the lipids recorded in the LIPID MAPS database by precursor ion m/z matching. The matched lipids are then filtered by the first-dimension retention time (1D RT), followed by the second-dimension retention time (2D RT), where the 2D RT of each lipid is predicted using an equivalent carbon number (ECN) model. The remaining assigned lipids are used for isotopic peak stripping via an iterative linear regression. The performance of Lipid Wizard was tested using a set of lipid standards and then applied to study the lipid changes in the livers of mice (fat-1) fed with alcohol.

DOI: https://doi.org/10.1021/acs.analchem.3c04419
J Chromatogr A. 2024 Mar 08. pii: S0021-9673(24)00176-6. [Epub ahead of print]1721 464803

A review of analytical parameters in 'rapid' liquid chromatographic methods for bioanalysis: Can we do better?

K Lawlor, J Clausen, A Johnston, A Edge, K Wolff, E Castrignanò, L Couchman.

  Rapid bioanalysis is beneficial to many applications. However, how 'rapid' a method is, or could be, is often an unanswered question. In this statistical review, the authors have assessed multiple pre-analytical (i.e. sample preparation), and analytical method parameters specifically for liquid chromatography to assist researchers in developing and validating 'rapid' bioanalytical methods. We restricted the search to urine and plasma matrices only. Data were extracted from over 2,000 recent studies and evaluated to assess how these parameters affected the 'on-instrument' analysis time. In addition to methods using ultra-violet (UV) detection, there were a large number of mass spectrometric (MS) methods, allowing additional review of the differences between high- and low-resolution MS on analysis time. We observed that most (N = 922, 70 %) methods used 5 or 10 cm columns, and that whilst uptake of ultra-high performance (U)HPLC columns was good, the use of sub-5 cm columns and/or flow rates in excess of 1 mL/min was incredibly rare (N = 25, 3 %). The detector of choice for quantitative (U)HPLC-MS remains the triple quadrupole, although a number of groups report the use of high-resolution MS for such methods.

Keywords:  Bioanalysis; Liquid chromatography; Mass spectrometry; Plasma; Rapid; Urine

DOI:  https://doi.org/10.1016/j.chroma.2024.464803
J Proteome Res. 2024 Mar 27.

SpectiCal: m/z Calibration of MS2 Peptide Spectra Using Known Low Mass Ions.

Nathan H Zhang, Eric W Deutsch.

  Most tandem mass spectrometry fragmentation spectra have small calibration errors that can lead to suboptimal interpretation and annotation. We developed SpectiCal, a software tool that can read mzML files from data-dependent acquisition proteomics experiments in parallel, compute m/z calibrations for each file prior to identification analysis based on known low-mass ions, and produce information about frequently observed peaks and their explanations. Using calibration coefficients, the data can be corrected to generate new calibrated mzML files. SpectiCal was tested using five public data sets, creating a table of commonly observed low-mass ions and their identifications. Information about the calibration and individual peaks is written in PDF and TSV files. This includes information for each peak, such as the number of runs in which it appears, the percentage of spectra in which it appears, and a plot of the aggregated region surrounding each peak. SpectiCal can be used to compute MS run calibrations, examine MS runs for artifacts that might hinder downstream analysis, and generate tables of detected low-mass ions for further analysis. SpectiCal is freely available at https://github.com/PlantProteomes/SpectiCal.

Keywords:  Mass spectrometry; SpectiCal; immonium ions; low-mass ions; proteomics; spectral calibration

DOI:  https://doi.org/10.1021/acs.jproteome.3c00882
Anal Chim Acta. 2024 Apr 29. pii: S0003-2670(24)00236-8. [Epub ahead of print]1300 342435

Derivatization of carboxylic groups prior to their LC analysis - A review.

Timotej Jankech, Ivana Gerhardtova, Petra Majerova, Juraj Piestansky, Josef Jampilek, Andrej Kovac.

  Carboxylic acids (CAs) represent a large group of important molecules participating in various biologically significant processes. Analytical study of these compounds is typically performed by liquid chromatography (LC) combined with various types of detection. However, their analysis is often accompanied by a wide variety of problems depending on used separation system or detection method. The dominant ones are: i) poor chromatographic behavior of the CAs in reversed-phase LC; ii) absence of a chromophore (or fluorophore); iii) weak ionization in mass spectrometry (MS). To overcome these problems, targeted chemical modification, and derivatization, come into play. Therefore, derivatization still plays an important and, in many cases, irreplaceable role in sample preparation, and new derivatization methods of CAs are constantly being developed. The most commonly used type of reaction for CAs derivatization is amidation. In recent years, an increased interest in the isotopic labeling derivatization method has been observed. In this review, we comprehensively summarize the possibilities and actual trends in the derivatization of CAs that have been published over the past decade.

Keywords:  Carboxylic acid; Chemical modification; Derivatization; Liquid chromatography

DOI:  https://doi.org/10.1016/j.aca.2024.342435
Rapid Commun Mass Spectrom. 2024 May 15. 38(9): e9721

Mass spectrometry imaging protocol for spatial mapping of lipids, N-glycans and peptides in murine lung tissue.

Yuen T Ngai, Matthew T Briggs, Parul Mittal, Clifford Young, Emma Parkinson-Lawrence, Manuela Klingler-Hoffmann, Sandra Orgeig, Peter Hoffmann.

RATIONALE: The application of matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) to murine lungs is challenging due to the spongy nature of the tissue. Lungs consist of interconnected air sacs (alveoli) lined by a single layer of flattened epithelial cells, which requires inflation to maintain its natural structure. Therefore, a protocol that is compatible with both lung instillation and high spatial resolution is essential to enable multi-omic studies on murine lung disease models using MALDI-MSI.
METHODS AND RESULTS: To maintain the structural integrity of the tissue, murine lungs were inflated with 8% (w/v) gelatin for lipid MSI of fresh frozen tissues or 4% (v/v) paraformaldehyde neutral buffer for N-glycan and peptide MSI of FFPE tissues. Tissues were sectioned and prepared for enzymatic digestion and/or matrix deposition. Glycerol-free PNGase F was applied for N-glycan MSI, while Trypsin Gold was applied for peptide MSI using the iMatrixSpray and ImagePrep Station, respectively. For lipid, N-glycan and peptide MSI, α-cyano-4-hydroxycinnamic acid matrix was deposited using the iMatrixSpray. MS data were acquired with 20 μm spatial resolution using a timsTOF fleX MS instrument followed by MS fragmentation of lipids, N-glycans and peptides. For lipid MSI, trapped ion mobility spectrometry was used to separate isomeric/isobaric lipid species. SCiLS™ Lab was used to visualize all MSI data. For analyte identification, MetaboScape®, GlycoMod and Mascot were used to annotate MS fragmentation spectra of lipids, N-glycans and tryptic peptides, respectively.
CONCLUSIONS: Our protocol provides instructions on sample preparation for high spatial resolution MALDI-MSI, MS/MS data acquisition and lipid, N-glycan and peptide annotation and identification from murine lungs. This protocol will allow non-biased analyses of diseased lungs from preclinical murine models and provide further insight into disease models.

DOI: https://doi.org/10.1002/rcm.9721
Analyst. 2024 Mar 25.

Multiple ion isolation and accumulation events for selective chemical noise reduction and dynamic range enhancement in MALDI imaging mass spectrometry.

Troy R Scoggins, Jonathan T Specker, Boone M Prentice.

Abundant chemical noise in MALDI imaging mass spectrometry experiments can impede the detection of less abundant compounds of interest. This chemical noise commonly originates from the MALDI matrix as well as other endogenous compounds present in high concentrations and/or with high ionization efficiencies. MALDI imaging mass spectrometry of biological tissues measures numerous biomolecular compounds that exist in a wide range of concentrations in vivo. When ion trapping instruments are used, highly abundant ions can dominate the charge capacity and lead to space charge effects that hinder the dynamic range and detection of lowly abundant compounds of interest. Gas-phase fractionation has been previously utilized in mass spectrometry to isolate and enrich target analytes. Herein, we have characterized the use of multiple continuous accumulations of selected ions (Multi CASI) to reduce the abundance of chemical noise and diminish the effects of space charge in MALDI imaging mass spectrometry experiments. Multi CASI utilizes the mass-resolving capability of a quadrupole mass filter to perform multiple sequential ion isolation events prior to a single mass analysis of the combined ion population. Multi CASI was used to improve metabolite and lipid detection in the MALDI imaging mass spectrometry analysis of rat brain tissue.

DOI: https://doi.org/10.1039/d4an00160e
J Chromatogr B Analyt Technol Biomed Life Sci. 2024 Mar 20. pii: S1570-0232(24)00098-9. [Epub ahead of print]1237 124090

A high-throughput method for the determination of 14 UV-filters in human plasma by LC-MS/MS: Minimize interferences from proteins and phospholipids in the matrix.

Wucheng Yang, Jianglu Feng, Wenyao Liang, Mingxia Nie, Jianhua Tan, Ruifang Fan.

  Accurate monitoring of UV-filters exposure levels in human plasma is a challenge because of the significant differences in the physicochemical properties of UV-filters, as well as the matrix effect caused by abundant proteins and phospholipids in plasma. Therefore, an effective and rapid method for simultaneous determination of 14 UV-filters in human plasma using protein precipitation-solid phase extraction (SPE) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Acetonitrile with 0.1 % formic acid and 10 % isopropanol (v/v) were used as mobile phases. A gradient elution on an ACQUITY UPLC BEH-C18 column at 30 °C and 0.3 mL/min flow rate was applied for separation. The electrospray ionization positive or negative modes were selected to determine the corresponding analyte to increase selectivity and sensitivity. Results showed that acetonitrile-tetrahydrofuran (v/v, 8:2) as the extraction solvent can effectively precipitate protein in plasma and improve the solubility of UV-filters. The HybridSPE cartridge improved the removal efficiency of phospholipids, while 1 mL of methanol elution increased the extraction recoveries of targets. Fourteen UV-filters achieved good linearities, low detection limits (0.050 to 0.10 μg/L) and quantification limits (0.10 to 1.0 μg/L). Method accuracy and precision, extraction recoveries, and storage stabilities of all analytes met the criterion of 80-120 %. Moreover, this method was successfully applied for the determination of UV-filters in plasma randomly collected from adults. Nine of 14 UV-filters were determined and their concentrations were distributed widely, suggesting a big variation of individual UV-filters exposure.

Keywords:  Human exposure; LC-MS/MS; Method validation; Plasma; UV-filters

DOI:  https://doi.org/10.1016/j.jchromb.2024.124090
Anal Chem. 2024 Mar 26.

Tandem Mass Spectrometry across Platforms.

Corey Hoang, Winnie Uritboonthai, Linh Hoang, Elizabeth M Billings, Aries Aisporna, Farshad A Nia, Rico J E Derks, James R Williamson, Martin Giera, Gary Siuzdak.

PubChem serves as a comprehensive repository, housing over 100 million unique chemical structures representing the breadth of our chemical knowledge across numerous fields including metabolism, pharmaceuticals, toxicology, cosmetics, agriculture, and many more. Rapid identification of these small molecules increasingly relies on electrospray ionization (ESI) paired with tandem mass spectrometry (MS/MS), particularly by comparison to genuine standard MS/MS data sets. Despite its widespread application, achieving consistency in MS/MS data across various analytical platforms remains an unaddressed concern. This study evaluated MS/MS data derived from one hundred molecular standards utilizing instruments from five manufacturers, inclusive of quadrupole time-of-flight (QTOF) and quadrupole orbitrap "exactive" (QE) mass spectrometers by Agilent (QTOF), Bruker (QTOF), SCIEX (QTOF), Waters (QTOF), and Thermo QE. We assessed fragment ion variations at multiple collisional energies (0, 10, 20, and 40 eV) using the cosine scoring algorithm for comparisons and the number of fragments observed. A parallel visual analysis of the MS/MS spectra across instruments was conducted, consistent with a standard procedure that is used to circumvent the still prevalent issue of mischaracterizations as shown for dimethyl sphingosine and C20 sphingosine. Our analysis revealed a notable consistency in MS/MS data and identifications, with fragment ions' m/z values exhibiting the highest concordance between instrument platforms at 20 eV, the other collisional energies (0, 10, and 40 eV) were significantly lower. While moving toward a standardized ESI MS/MS protocol is required for dependable molecular characterization, our results also underscore the continued importance of corroborating MS/MS data against standards to ensure accurate identifications. Our findings suggest that ESI MS/MS manufacturers, akin to the established norms for gas chromatography mass spectrometry instruments, should standardize the collision energy at 20 eV across different instrument platforms.

DOI: https://doi.org/10.1021/acs.analchem.3c05576
Foods. 2024 Mar 13. pii: 866. [Epub ahead of print]13(6):

Dispersive Solid-Phase Extraction and Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry-A Rapid and Accurate Method for Detecting 10 Macrolide Residues in Aquatic Products.

Jinyu Chen, Guangming Mei, Xiaojun Zhang, Daoxiang Huang, Pengfei He, Dan Xu.

  The amount of macrolide (MAL) residues in aquatic products, including oleandomycin (OLD), erythromycin (ERM), clarithromycin (CLA), azithromycin (AZI), kitasamycin (KIT), josamycin (JOS), spiramycin (SPI), tilmicosin (TIL), tylosin (TYL), and roxithromycin (ROX), was determined using solid-phase extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The residues were extracted with 1% ammonia acetonitrile solution and purified by neutral alumina adsorption. Chromatographic separation was completed on an ACQUITY UPLC BEH C18 column with acetonitrile-0.1% formic acid aqueous solution as the mobile phase, and mass spectrometry detection was performed by multiple reaction monitoring scanning with the positive mode in an electrospray ion source (ESI+). Five isotopically labeled compounds were used as internal standards for quality control purposes. The findings indicated that across the mass concentration span of 1.0-100 μg/L, there was a strong linear correlation (R2 > 0.99) between the concentration and instrumental response for the 10 MALs. The limit of detection of UPLC-MS/MS was 0.25-0.50 μg/kg, and the limit of quantitation was 0.5-1.0 μg/kg. The added recovery of blank matrix samples at standard gradient levels (1.0, 5.0, and 50.0 μg/kg) was 83.1-116.6%, and the intra-day precision and inter-day precisions were 3.7 and 13.8%, respectively. The method is simple and fast, with high accuracy and good repeatability, in line with the requirements for accurate qualitative and quantitative analysis of the residues for 10 MALs in aquatic products.

Keywords:  LC-MS/MS; antibiotic residue; isotopically labelled internal standard; macrolide; solid-phase extraction

DOI:  https://doi.org/10.3390/foods13060866
J Exp Bot. 2024 Mar 25. pii: erae129. [Epub ahead of print]

Comprehensive LC-MS/MS Analysis of Nitrogen-Related Plant Metabolites.

Sanja Ćavar Zeljković, Nuria De Diego, Lukáš Drašar, Jaroslav Nisler, Libor Havlíček, Lukáš Spíchal, Petr Tarkowski.

  We have developed and validated a novel LC-MS/MS method for simultaneously analyzing amino acids, biogenic amines, and their acetylated and methylated derivatives in plants. This method involves a one-step extraction of 2-5 mg of lyophilized plant material followed by fractionation of different biogenic amine forms and exploits an efficient combination of hydrophilic interaction chromatography (HILIC), reversed phase (RP) chromatography with pre-column derivatization, and tandem mass spectrometry. This approach enables high-throughput processing of plant samples, significantly reducing the time needed for analysis and its cost. We also present a new synthetic route for deuterium-labelled polyamines. The LC-MS/MS method was rigorously validated by quantifying levels of nitrogen-related metabolites in seedlings of seven plant species including Arabidopsis, maize, and barley, all of which are commonly used model organisms in plant science research. Our results revealed substantial variations in the abundance of these metabolites between species, developmental stages, and growth conditions, particularly for the acetylated and methylated derivatives and the various polyamine fractions. However, the biological relevance of these plant metabolites is currently unclear. Overall, this work contributes significantly to the field of plant science by providing a powerful analytical tool and setting the stage for future investigations into the functions of these nitrogen-related metabolites in plants.

Keywords:  LC-MS/MS; acetylated amino acids; acetylated biogenic amines; amino acids; biogenic amines; methylated amino acids; plant metabolism

DOI:  https://doi.org/10.1093/jxb/erae129
J Chromatogr Sci. 2024 Mar 28. pii: bmae013. [Epub ahead of print]

Simultaneous Determination of D and L Enantiomers of 2-Hydroxyglutarate by UHPLC-MS/MS Method in Human Biological Fluids and its Clinical Application.

Xiaoqing Li, Yunhai Bo, Le Le, Fen Yang.

2-hydroxyglutarate has limited abundance in normal tissues but a high level under certain pathologic conditions. To clarify the diagnostic value of two chiral isomers of 2-hydroxyglutarate in plasma and urine of Chinese cancer patients, an ultra-high performance liquid chromatography-tandem mass spectrometric method was developed for simultaneous quantification of D-/L-2-hydroxyglutarate. The selected D-/L-2-hydroxyglutarate-d5 as internal standards were added to samples before the SPE on Waters Oasis® MAX 96-Well plate (30 μm, 60 mg). A derivatization step with (+)-O,O'-diacetyl-L-tartaric anhydride permitted the chromatography separation of D-/L-2-hydroxyglutarate on an ACQUITY UPLC-HSS T3 column (50 × 2.1 mm, i.d. 1.8 μm) with acetonitrile and water (containing 0.1% formic acid and 10 mmol ammonium acetate) as the mobile phase. The calibration curves showed good linearity (R ≥ 0.99) over the concentration ranges of 200-5,000 ng/mL and 500-20,000 ng/mL for analysis of D-/L-2-hydroxyglutarate in plasma and urine samples, respectively. Intra- and inter-run precision were ≤ 12.33%, and the accuracy was within the range of -10.44 to 13.90%. This method was further successfully applied to clinical sample analysis in isocitrate dehydrogenase 1/2 mutated Chinese cancer patients.

DOI: https://doi.org/10.1093/chromsci/bmae013
Toxins (Basel). 2024 Mar 01. pii: 129. [Epub ahead of print]16(3):

Detection of Anatoxins in Human Urine by Liquid Chromatography Triple Quadrupole Mass Spectrometry and ELISA.

Brady R Cunningham, Sarah R Lagon, William A Bragg, Donna Hill, Elizabeth I Hamelin.

  Harmful cyanobacterial blooms are becoming more common and persistent around the world. When in bloom, various cyanobacterial strains can produce anatoxins in high concentrations, which, unlike other cyanobacterial toxins, may be present in clear water. Potential human and animal exposures to anatoxins occur mainly through unintentional ingestion of contaminated algal mats and water. To address this public health threat, we developed and validated an LC-MS/MS method to detect anatoxins in human urine to confirm exposures. Pooled urine was fortified with anatoxin-a and dihydroanatoxin at concentrations from 10.0 to 500 ng/mL to create calibrators and quality control samples. Samples were diluted with isotopically labeled anatoxin and solvent prior to LC-MS/MS analysis. This method can accurately quantitate anatoxin-a with inter- and intraday accuracies ranging from 98.5 to 103% and relative standard deviations < 15%, which is within analytical guidelines for mass spectrometry methods. Additionally, this method qualitatively detects a common degradation product of anatoxin, dihydroanatoxin, above 10 ng/mL. We also evaluated a commercial anatoxin-a ELISA kit for potential diagnostic use; however, numerous false positives were detected from unexposed individual human urine samples. In conclusion, we have developed a method to detect anatoxins precisely and accurately in urine samples, addressing a public health area of concern, which can be applied to future exposure events.

Keywords:  ELISA; LC-MS/MS; anatoxins; clinical; dog; harmful algal blooms; harmful cyanobacterial blooms; mouse; urine

DOI:  https://doi.org/10.3390/toxins16030129
Compr Rev Food Sci Food Saf. 2024 Mar;23(2): e13325

From sound check to encore: A journey through high-resolution mass spectrometry-based food analyses and metabolomics.

Francisco José Díaz-Galiano, María Murcia-Morales, Amadeo Rodríguez Fernández-Alba.

  This manuscript presents a comprehensive review of high-resolution mass spectrometry in the field of food analysis and metabolomics. We have followed the historical evolution of metabolomics, its associated techniques and technologies, and its increasing role in food science and research. The review provides a critical comparison and synthesis of tentative identification guidelines proposed for over 15 years, offering a condensed resource for researchers in the field. We have also examined a wide range of recent metabolomics studies, showcasing various methodologies and highlighting key findings as a testimony of the versatility of the field and the possibilities it offers. In doing so, we have also carefully provided a compilation of the software tools that may be employed in this type of studies. The manuscript also explores the prospects of high-resolution mass spectrometry and metabolomics in food science. By covering the history, guidelines, applications, and tools of metabolomics, this review attempts to become a comprehensive guide for researchers in a rapidly evolving field.

Keywords:  authenticity; chemometrics; metabolomics; orbitrap; time‐of‐flight

DOI:  https://doi.org/10.1111/1541-4337.13325
Anal Chem. 2024 Mar 29.

Magnetic Particle Spray Mass Spectrometry.

Tássia Venga Mendes, Eduardo Costa Figueiredo.

In this work, the concept of magnetic particle spray mass spectrometry (MPS-MS) is reported for the first time. Magnetic sorbent particles are used to extract the analytes from a liquid sample. The particles are magnetically attracted to the tip of a magnetic probe that is positioned at the entrance of the mass spectrometer. A solvent is dispensed on the particles, and a high voltage promotes the formation of the Taylor cone around the particles agglomerate. Analytes are desorbed by the solvent, ionized, and analyzed by mass spectrometry. MPS-MS is totally in consonance with the green chemistry principle. A minimal consumption of sample (100 μL), solvent (34 μL), and magnetic sorbent (500 μg) is needed per analysis for an excellent performance of MPS-MS in terms of sensitivity and selectivity. The determination of amitriptyline, citalopram, clomipramine, chlorpromazine, doxepin, haloperidol, nortriptyline, and venlafaxine in human plasma samples using magnetic restricted-access carbon nanotubes was carried out as a proof of principle. Limits of quantification of 10 μg L-1 and correlation coefficients higher than 0.98 were obtained for all of the analytes. Limits of detection ranged from 0.43 to 2.82 μg L-1. Precision (as relative standard deviation) and accuracies (as relative error) ranged from 3.6 to 23.6%, as well as -12.8 to 18.7%, respectively. MPS-MS opens a new line of developments in the association of sample preparation with ambient ionization. New sorbents, device configurations, and physical and chemical conditions can also be analyzed for the analysis of many other analytes in different samples.

DOI: https://doi.org/10.1021/acs.analchem.3c05680
Forensic Toxicol. 2024 Mar 22.

Development of a simple screening method for analyzing cereulide toxin in fried rice using liquid chromatography-tandem mass spectrometry.

Hiroshi Koike, Maki Kanda, Chie Monma, Souichi Yoshikawa, Hiroshi Hayashi, Yoko Matsushima, Yumi Ohba, Momoka Hayashi, Natsumi Furuta, Wakaba Okada, Chieko Nagano, Keiko Yokoyama, Tomoko Yokoyama, Takeo Sasamoto.

   PURPOSE: The presence of cereulide, an emetic toxin produced by Bacillus cereus, in fried rice samples is critical evidence of food poisoning even in situations where B. cereus could not be detected. This study aims to develop a screening method for analyzing cereulide in fried rice using the QuEChERS procedure and liquid chromatography-tandem mass spectrometry (LC-MS/MS).
METHODS: Cereulide was identified and quantified in fried rice samples using the QuEChERS extraction method and LC-MS/MS. The accuracies of the methods were determined by analyzing fortified blank samples at two concentrations (10 and 50 µg/kg) conducted on three samples daily for five days.
RESULTS: The QuEChERS procedure removed matrix compounds from fried rice. Characteristic MS/MS spectra enabled the identification of cereulide. As the matrix effects in seven fried rice samples were within ± 6%, an external solvent calibration curve could be used for quantification. This method exhibited good accuracy ranging from 88 to 89%. The relative standard deviations for both repeatability and intra-laboratory reproducibility were < 4%. These standard deviations satisfied the criteria of the Japanese validation guidelines for residues (MHLW 2010, Director Notice, Syoku-An No. 1224-1). The limit of quantification was 2 μg/kg. The applicability of this method was confirmed using the analysis of cereulide in fried rice samples incubated with emetic Bacillus cereus.
CONCLUSIONS: The QuEChERS extraction procedure described herein showed substantial promise as a reliable screening tool for cereulide in fried rice sample.

Keywords:  Cereulide; Fried rice; Liquid chromatography-tandem mass spectrometry; QuEChERS; Screening

DOI:  https://doi.org/10.1007/s11419-024-00683-3
Scand J Clin Lab Invest. 2024 Mar 26. 1-6

LC-MS/MS analysis of 11-nor-9-carboxy-hexahydrocannabinol (HHC-COOH) and 11-hydroxy-hexahydrocannabinol (HHC-OH) for verification of hexahydrocannabinol (HHC) intake.

Paul Pettersson-Pablo, Joakim Oxelbark.

  Natural and semi-synthetic cannabinoid analogs are getting increasing media attention for their recreative use as an alternative to traditional cannabis, in Sweden as well as internationally. To investigate an increasing number of urine samples incoming to our clinical laboratory that were screening positive, using a CEDIA THC-COOH immunoassay from ThermoFisher Scientific, but then testing negative using GC-MS based verification analysis, we developed an LC-MS/MS-method for verification of hexahydrocannabinol (HHC) and Δ8-tetrahydrocannabinol. Assessment of HHC intake was based on identification of the following four metabolites: 11-nor-9(R)-carboxy-hexahydrocannabinol (R-HHC-COOH), 11-nor-9(S)-carboxy-hexahydrocannabinol (S-HHC-COOH), 11-hydroxy-9(R)-hexahydrocannabinol (R-HHC-OH) and 11-hydroxy-9(S)-hexahydrocannabinol (S-HHC-OH). Out of 46 urine samples analysed in this study, 44 showed presence of HHC-metabolites, which indicate HHC as the main explanation for an increased number of negative verifications for THC-COOH. In these samples, the HHC-OH metabolites occurred at a higher concentration than R-HHC-COOH while S-HHC-COOH was only detected in few samples at low concentrations. R-HHC-COOH and S-HHC-COOH can easily be added to a pre-existing verification method for THC-COOH, and still show acceptable results, while HHC-OH requires an enzyme capable of hydrolysing the ether glucuronide bond.

Keywords:  Cannabis; cannabinoids; hydrolysis; immunoassay; liquid Chromatography-Mass spectrometry; narcotics; urine

DOI:  https://doi.org/10.1080/00365513.2024.2333023
J Chromatogr A. 2024 Mar 18. pii: S0021-9673(24)00197-3. [Epub ahead of print]1721 464824

Two-dimensional liquid chromatography with reversed phase in both dimensions: A review.

Alshymaa A Aly, Tadeusz Górecki.

  Two-dimensional liquid chromatography (2D-LC), and in particular comprehensive two-dimensional liquid chromatography (LC×LC), offers increased peak capacity, resolution and selectivity compared to one-dimensional liquid chromatography. It is commonly accepted that the technique produces the best results when the separation mechanisms in the two dimensions are completely orthogonal; however, the use of similar separation mechanisms in both dimensions has been gaining popularity as it helps avoid difficulties related to mobile phase incompatibility and poor column efficiency. The remarkable advantages of using reversed phase in both dimensions (RPLC×RPLC) over other separation mechanisms made it a promising technique in the separation of complex samples. This review discusses some physical and practical considerations in method development for 2D-LC involving the use of RP in both dimensions. In addition, an extensive overview is presented of different applications that relied on RPLC×RPLC and 2D-LC with reversed phase column combinations to separate components of complex samples in different fields including food analysis, natural product analysis, environmental analysis, proteomics, lipidomics and metabolomics.

Keywords:  2D-LC applications; Method development; Method optimization; Reversed phase; Two-dimensional liquid chromatography

DOI:  https://doi.org/10.1016/j.chroma.2024.464824
Environ Sci Technol. 2024 Mar 27.

Development and Application of a Multidimensional Database for the Detection of Quaternary Ammonium Compounds and Their Phase I Hepatic Metabolites in Humans.

Ryan Nguyen, Ryan P Seguin, Dylan H Ross, Pengyu Chen, Sean Richardson, Jennifer Liem, Yvonne S Lin, Libin Xu.

  The COVID-19 pandemic has led to significantly increased human exposure to the widely used disinfectants quaternary ammonium compounds (QACs). Xenobiotic metabolism serves a critical role in the clearance of environmental molecules, yet limited data are available on the routes of QAC metabolism or metabolite levels in humans. To address this gap and to advance QAC biomonitoring capabilities, we analyzed 19 commonly used QACs and their phase I metabolites by liquid chromatography-ion mobility-tandem mass spectrometry (LC-IM-MS/MS). In vitro generation of QAC metabolites by human liver microsomes produced a series of oxidized metabolites, with metabolism generally occurring on the alkyl chain group, as supported by MS/MS fragmentation. Discernible trends were observed in the gas-phase IM behavior of QAC metabolites, which, despite their increased mass, displayed smaller collision cross-section (CCS) values than those of their respective parent compounds. We then constructed a multidimensional reference SQLite database consisting of m/z, CCS, retention time (rt), and MS/MS spectra for 19 parent QACs and 81 QAC metabolites. Using this database, we confidently identified 13 parent QACs and 35 metabolites in de-identified human fecal samples. This is the first study to integrate in vitro metabolite biosynthesis with LC-IM-MS/MS for the simultaneous monitoring of parent QACs and their metabolites in humans.

Keywords:  COVID-19; biomonitoring; database; disinfectants; ion mobility–mass spectrometry (IM–MS); quaternary ammonium compounds (QACs); xenobiotic metabolism

DOI:  https://doi.org/10.1021/acs.est.3c10845