bims-metlip Biomed News
on Methods and protocols in metabolomics and lipidomics
Issue of 2023‒08‒20
27 papers selected by
Sofia Costa

  1. Anal Bioanal Chem. 2023 Aug 17.
      Data-independent acquisition (DIA) mode in liquid chromatography (LC) high-resolution mass spectrometry (HRMS) has emerged as a powerful strategy in untargeted metabolomics for detecting a broad range of metabolites. However, the use of this approach also represents a challenge in the analysis of the large datasets generated. The regions of interest (ROI) multivariate curve resolution (MCR) approach can help in the identification and characterization of unknown metabolites in their mixtures by linking their MS1 and MS2 DIA spectral signals. In this study, it is proposed for the first time the analysis of MS1 and MS2 DIA signals in positive and negative electrospray ionization modes simultaneously to increase the coverage of possible metabolites present in biological systems. In this work, this approach has been tested for the detection and identification of the amino acids present in a standard mixture solution and in fish embryo samples. The ROIMCR analysis allowed for the identification of all amino acids present in the analyzed mixtures in both positive and negative modes. The methodology allowed for the direct linking and correspondence between the MS signals in their different acquisition modes. Overall, this approach confirmed the advantages and possibilities of performing the proposed ROIMCR simultaneous analysis of mass spectrometry signals in their differing acquisition modes in untargeted metabolomics studies.
    Keywords:  All-ion fragmentation (AIF); Metabolite coverage improvement; Positive and negative acquisition modes; ROIMCR, Regions of interest multivariate curve resolution; Untargeted metabolomics
  2. Eur J Mass Spectrom (Chichester). 2023 Aug 15. 14690667231194812
      The aim of this paper was to develop, validate, and utilize a sensitive liquid chromatography-tandem mass spectrometry bioanalytical method for bioequivalence/clinical trial studies conducted in human plasma. To accomplish the target, a stable labeled internal standard, that is, dexamethasone D4 was used as an internal standard to track and compensate the parent compound during processing, and extraction from plasma. The method involves a rapid liquid-liquid phase extraction from plasma, followed by reverse phase chromatography, and mass spectrometry detection, with a total run time of 3.5 min. The method was developed and validated from 2 to 600 ng/ml for dexamethasone. The mean recovery for dexamethasone was found to be 81.0%. The validated method enabled the analysis of dexamethasone in samples from clinical pharmacokinetic studies. The peak concentration of dexamethasone ranged between 253 to 281 ng/ml and 319 to 343 ng/ml, respectively, in fasted and fed conditions. The terminal half-life values for dexamethasone ranged between 3.5 to 8.2 h and 3.0 to 7.5 h, respectively.
    Keywords:  Dexamethasone; LC-MS/MS; bioequivalence; human plasma
  3. STAR Protoc. 2023 Aug 16. pii: S2666-1667(23)00367-2. [Epub ahead of print]4(3): 102400
      Primary metabolites are molecules of essential biochemical reactions that define the biological phenotype. All primary metabolites cannot be measured in a single analysis. In this protocol, we outline the multiplexed and quantitative measurement of 106 metabolites that cover the central part of primary metabolism. The protocol includes several sample preparation techniques and one liquid chromatography-mass spectrometry method. Then, we describe the steps of the bioinformatic data analysis to better understand the metabolic perturbations that may occur in a biological system. For complete details on the use and execution of this protocol, please refer to: Costanza et al.,1 Blomme et al.,2 Blomme et al.,3 Guillon et al.,4 Stuani et al.5.
    Keywords:  Mass Spectrometry; Metabolomics
  4. Bioanalysis. 2023 Aug 16.
      We have developed and validated a novel LC-MS/MS method for the simultaneous quantification of LB-100 and its active metabolite, endothall, in human plasma following solid-phase extraction. LB-105 and endothall-D6 were used as internal standards. Chromatographic separation was achieved on a Hypercarb™ column using 5 mM (NH4)2CO3 and 30:70 (v/v) 100 mM (NH4)2CO3:acetonitrile as mobile phases. Detection was performed via positive electrospray ionization mode with multiple reaction monitoring. The assay exhibited linearity in the concentration range of 2.5-500 ng/ml for both analytes. Intra- and inter-assay precision and accuracy were within ±11%. LB-100 and endothall recoveries were 78.7 and 86.7%, respectively. The validated LC-MS/MS method enabled the accurate measurement of LB-100 and endothall in patient samples from an ongoing clinical trial (NCT04560972).
    Keywords:  LB-100; LC–MS; chromatography; endothall; human plasma; mass spectrometry; oncology; pharmacokinetics; validation
  5. Pharmazie. 2023 Aug 01. 78(8): 107-112
      Capecitabine is an anticancer agent and is the oral prodrug of 5-fluorouracil (5-FU). In this study, an ultra-high performance liquid chromatography coupled to turbo ion spray tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to quantify capecitabine and its metabolites including 5'-deoxy-5-fluorocytidine (5'-dFCR), 5'-deoxy-5-fluorouridine (5'-dFUR), 5-FU, and fluoro-β-alanine (FBAL) in lithium heparinized human plasma. Analytes were extracted by protein precipitation, chromatographically separated by Acquity UPLC HSS T3 column with gradient elution, and analyzed with a tandem mass spectrometer equipped with an electrospray ionization source. Capecitabine and 5'-dFCR were quantified in positive ion mode and 5'-dFUR, 5-FU, and FBAL were quantified in negative ion mode. The total chromatographic run time was 9 min. Stable isotopically labeled internal standards were used for all analytes. The assay was validated over the range from 25.0 to 2,500 ng/mL for capecitabine, 10.0 to 1,000 ng/mL for 5'-dFCR, 5'-dFUR, and 5-FU and 50 to 5,000 ng/ mL for FBAL in human plasma. Validation results have shown the developed assay allows for reliable quantitative analysis of capecitabine, 5'-dFCR, 5'-dFUR, 5-FU, and FBAL in plasma samples. Capecitabine is an anticancer agent and is the oral prodrug of 5-fluorouracil (5-FU). In this study, an ultra-high performance liquid chromatography coupled to turbo ion spray tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to quantify capecitabine and its metabolites including 5'-deoxy-5-fluorocytidine (5'-dFCR), 5'-deoxy-5-fluorouridine (5'-dFUR), 5-FU, and fluoro-β-alanine (FBAL) in lithium heparinized human plasma. Analytes were extracted by protein precipitation, chromatographically separated by Acquity UPLC HSS T3 column with gradient elution, and analyzed with a tandem mass spectrometer equipped with an electrospray ionization source. Capecitabine and 5'-dFCR were quantified in positive ion mode and 5'-dFUR, 5-FU, and FBAL were quantified in negative ion mode. The total chromatographic run time was 9 min. Stable isotopically labeled internal standards were used for all analytes. The assay was validated over the range from 25.0 to 2,500 ng/mL for capecitabine, 10.0 to 1,000 ng/mL for 5'-dFCR, 5'-dFUR, and 5-FU and 50 to 5,000 ng/ mL for FBAL in human plasma. Validation results have shown the developed assay allows for reliable quantitative analysis of capecitabine, 5'-dFCR, 5'-dFUR, 5-FU, and FBAL in plasma samples.
  6. MethodsX. 2023 Dec;11 102303
      Currently, the interest in polyphenols is increasing due to their significant properties in health. Polyphenols exist in a range of natural products, however their extraction as well as their characterization are important issues as they are mainly present in complex matrices. Therefore, sensitive and selective analytical methods based on liquid chromatography coupled to tandem mass spectrometry are essential. Nevertheless, access to such high-resolution techniques is quite rare. Thus, in this work we present a simple, selective and robust method based on a single-quadrupole (Q) MS technique) for the analysis of a wide range of polyphenols such as flavonoids, phenolic acids and anthocyanins. Specifically, we present:•A simple liquid chromatography electro-spray ionization (LC-ESI) single-quadrupole mass selective (MS) method for the analysis of 18 different polyphenols.•Application of the method to three plant-based extracts that are derived after green extraction methods.
    Keywords:  A simple and robust LC-ESI single quadrupole MS-based method to analyze polyphenols in plant extracts; Antioxidants; LC-ESI method; MS method; Polyphenols; plant antioxidants
  7. Anal Chem. 2023 Aug 18.
      Probing the entirety of any species metabolome is an analytical grand challenge, especially on a cellular scale. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) is a common spatial metabolomics assay, but this technique has limited molecular coverage for several reasons. To expand the application space of spatial metabolomics, we developed an on-tissue chemical derivatization (OTCD) workflow using 4-APEBA for the confident identification of several dozen elusive phytocompounds. Overall, this new OTCD method enabled the annotation of roughly 280 metabolites, with only a 10% overlap in metabolic coverage when compared to analog negative ion mode MALDI-MSI on serial sections. We demonstrate that 4-APEBA outperforms other derivatization agents by providing: (1) broad specificity toward carbonyls, (2) low background, and (3) introduction of bromine isotopes. Notably, the latter two attributes also facilitate more confidence in our bioinformatics for data processing. The workflow detailed here trailblazes a path toward spatial hormonomics within plant samples, enhancing the detection of carboxylates, aldehydes, and plausibly other carbonyls. As such, several phytohormones, which have various roles within stress responses and cellular communication, can now be spatially profiled, as demonstrated in poplar root and soybean root nodule.
  8. J Am Soc Mass Spectrom. 2023 Aug 16.
      Prostaglandins (PGs) are important lipid mediators involved in physiological processes, such as inflammation and pregnancy. The pleiotropic effects of the PG isomers and their differential expression from cell types impose the necessity for studying individual isomers locally in tissue to understand the molecular mechanisms. Currently, mass spectrometry (MS)-based analytical workflows for determining the PG isomers typically require homogenization of the sample and a separation method, which results in a loss of spatial information. Here, we describe a method exploiting the cationization of PGs with silver ions for enhanced sensitivity and tandem MS to distinguish the biologically relevant PG isomers PGE2, PGD2, and Δ12-PGD2. The developed method utilizes characteristic product ions in MS3 for training prediction models and is compatible with direct infusion approaches. We discuss insights into the fragmentation pathways of Ag+ cationized PGs during collision-induced dissociation and demonstrate the high accuracy and robustness of the model to predict isomeric compositions of PGs. The developed method is applied to mass spectrometry imaging (MSI) of mouse uterus implantation sites using silver-doped pneumatically assisted nanospray desorption electrospray ionization and indicates localization to the antimesometrial pole and the luminal epithelium of all isomers with different abundances. Overall, we demonstrate, for the first time, isomeric imaging of major PG isomers with a simple method that is compatible with liquid-based extraction MSI methods.
  9. Rapid Commun Mass Spectrom. 2023 Sep 30. 37(18): e9611
      RATIONALE: Recently, there has been a report suggesting that ecdysteroids can enhance sports performance, making them relevant substances in doping control. Hence, it is imperative to examine the analytical characteristics of ecdysteroids in biological samples to identify their misuse in competitive sports.METHODS: To assess the doping of ecdysteroids such as ecdysone, ecdysterone, ponasterone A, turkesterone, and ajugasterone C, a fast and sensitive extraction and detection method was developed, optimized, and validated using equine urine and plasma. Different extraction techniques, namely, solid-phase extraction, liquid-liquid extraction, and dilute-and-inject, were explored to detect ecdysteroids from equine urine and plasma.
    RESULTS: The most suitable method of detection was solid-phase extraction using ABS Elut-NEXUS, while liquid-liquid extraction and dilute-and-inject methods encountered difficulties due to the high polarity of ecdysteroids and the presence of significant matrix interferences. Mass spectrometric parameters are optimized on both the Q Exactive high-resolution mass spectrometer and the TSQ Altis triple quadrupole mass spectrometer. However, the study indicated that the triple quadrupole mass spectrometer exhibited improved limit of detection when analyzing samples. To achieve optimal separation of the analytes under investigation from the matrix interferences, various liquid chromatography columns were compared. The Selectra PFPP LC column with a mobile phase consisting of 0.2% formic acid in water (mobile phase A) and acetonitrile (mobile phase B) at a flow rate of 0.5 mL/min demonstrated superior performance.
    CONCLUSIONS: The findings of this study will significantly contribute to the accurate identification of ecdysteroids, facilitating the investigation of their illicit use in horse racing.
  10. Electrophoresis. 2023 Aug 13.
      For studying stem cell-derived islet organoids (SC-islets) in an organ-on-chip (OoC) platform, we have developed a reversed-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS) method allowing for simultaneous determination of insulin, somatostatin-14, and glucagon, with improved matrix robustness compared to earlier methodology. Combining phenyl/hexyl-C18 separations using 2.1 mm inner diameter LC columns and triple quadrupole mass spectrometry, identification and quantification were secured with negligible variance in retention time and quantifier/qualifier ratios, negligible levels of carryover (<2%), and sufficient precision (±10% RSD) and accuracy (±15% relative error) with and without use of an internal standard. The obtained lower limits of quantification were 0.2 µg/L for human insulin, 0.1 µg/L for somatostatin-14, and 0.05 µg/L for glucagon. The here-developed RPLC-MS/MS method showed that the SC-islets have an insulin response dependent on glucose concentration, and the SC-islets produce and release somatostatin-14 and glucagon. The RPLC-MS/MS method for these peptide hormones was compatible with an unfiltered offline sample collection from SC-islets cultivated on a pumpless, recirculating OoC (rOoC) platform. The SC-islets background secretion of insulin was not significantly different on the rOoC device compared to a standard cell culture well-plate. Taken together, RPLC-MS/MS method is well suited for multi-hormone measurements of SC-islets on an OoC platform.
    Keywords:  glucose regulatory hormones; liquid chromatography-tandem mass spectrometry; organ-on-chip; stem cell-derived islet organoids
  11. Anal Chem. 2023 Aug 18.
      Metabolomics based on high-resolution mass spectrometry has become a powerful technique in biomedical research. The development of various analytical tools and online libraries has promoted the identification of biomarkers. However, how to make mass spectrometry collect more data information is an important but underestimated research topic. Herein, we combined full-scan and data-dependent acquisition (DDA) modes to develop a new targeted DDA based on the inclusion list of differential and preidentified ions (dpDDA). In this workflow, the MS1 datasets for statistical analysis and metabolite preidentification were first obtained using full-scan, and then, the MS/MS datasets for metabolite identification were obtained using targeted DDA of quality control samples based on the inclusion list. Compared with the current methods (DDA, data-independent acquisition, targeted DDA with time-staggered precursor ion list, and iterative exclusion DDA), dpDDA showed better stability, higher characteristic ion coverage, higher differential metabolites' MS/MS coverage, and higher quality MS/MS spectra. Moreover, the same trend was verified in the analysis of large-scale clinical samples. More surprisingly, dpDDA can distinguish patients with different severities of coronary heart disease (CHD) based on the Canadian Cardiovascular Society angina classification, which we cannot distinguish through conventional metabolomics data collection. Finally, dpDDA was employed to differentiate CHD from healthy control, and targeted metabolomics confirmed that dpDDA could identify a more complete metabolic pathway network. At the same time, four unreported potential CHD biomarkers were identified, and the area under the receiver operating characteristic curve was greater than 0.85. These results showed that dpDDA would expand the discovery of biomarkers based on metabolomics, more comprehensively explore the key metabolites and their association with diseases, and promote the development of precision medicine.
  12. Rapid Commun Mass Spectrom. 2023 Sep 15. 37(17): e9602
      RATIONALE: Isolation of underivatized amino acids (AAs) using high-performance liquid chromatography (HPLC) is becoming a popular method for carbon (δ13 C) and nitrogen isotope (δ15 N) analyses of AAs because of the high analytical precision and for performing dual-isotope analysis. However, some AAs in natural samples, especially small, hydrophilic AAs, are not suitably separated using reversed-phase columns (e.g., C18) and ion-exchange columns (e.g., Primesep A).METHODS: We developed a new method for HPLC using a porous graphitic carbon column for the separation of nine hydrophilic AAs. After purification, δ13 C and δ15 N values of AAs were determined using elemental analyzer/isotope ratio mass spectrometry (EA/IRMS). We demonstrated the application of this method by determining δ13 C and δ15 N values of individual hydrophilic AAs in a biological sample, the muscle of blue mackerel (Scomber australasicus).
    RESULTS: Chromatographically, the baseline separation of hydrophilic AAs was achieved in both the standard mixture and the biological sample. We confirmed that δ13 C and δ15 N values of AA standards remained unchanged during the whole experimental procedure. The δ13 C values of AAs in mackerel muscle are also in good agreement with the values obtained using another verified method for δ13 C analysis.
    CONCLUSIONS: The good separation performance of hydrophilic AAs and the reliability of δ13 C and δ15 N analyses of individual AAs using the porous graphite column offer a significant advantage over conventional settings. We suggest that, in the future, the HPLC × EA/IRMS method can be used for reliable δ13 C and δ15 N analyses of AAs in natural samples.
  13. Anal Chem. 2023 Aug 14.
      Non-targeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a widely used tool for metabolomics analysis, enabling the detection and annotation of small molecules in complex environmental samples. Data-dependent acquisition (DDA) of product ion spectra is thereby currently one of the most frequently applied data acquisition strategies. The optimization of DDA parameters is central to ensuring high spectral quality, coverage, and number of compound annotations. Here, we evaluated the influence of 10 central DDA settings of the Q Exactive mass spectrometer on natural organic matter samples from ocean, river, and soil environments. After data analysis with classical and feature-based molecular networking using MZmine and GNPS, we compared the total number of network nodes, multivariate clustering, and spectrum quality-related metrics such as annotation and singleton rates, MS/MS placement, and coverage. Our results show that automatic gain control, microscans, mass resolving power, and dynamic exclusion are the most critical parameters, whereas collision energy, TopN, and isolation width had moderate and apex trigger, monoisotopic selection, and isotopic exclusion minor effects. The insights into the data acquisition ergonomics of the Q Exactive platform presented here can guide new users and provide them with initial method parameters, some of which may also be transferable to other sample types and MS platforms.
  14. Rapid Commun Mass Spectrom. 2023 Sep 15. 37(17): e9598
      BACKGROUND: The aim of this study was to determine the concentration of rosmarinic acid (RA) and its analog (E)-3-(3,4-dihydroxyphenyl)-2-(3-(3,4-dihydroxyphenyl)acrylamido)propanoic acid (A1) in rat plasma following oral administration. The significance of this study lies in the development of a rapid, sensitive, and alternative method using liquid chromatography-tandem mass spectrometry for the accurate quantification and identification of RA and A1 in vivo.METHODS: Liquid chromatography-tandem mass spectrometry was employed to analyze RA and A1 in rat plasma. A C18 column (1.9 µm, 2.1 × 100 mm) with a C18 guard column (5 µm, 2.1 × 10 mm) and a triple-quadrupole mass spectrometer combined with an electrospray ionization source were utilized. Sample pretreatment involved a one-step protein precipitation using isopropanol:ethyl acetate (20:80, v/v) as the solvent. Pseudoephedrine hydrochloride served as a standard.
    RESULTS: The developed method exhibited a linear relationship within the concentration ranges of 5-750 ng/ml for both RA and A1. Relative standard deviations in daily courses were less than 15%, and the relative errors recorded were within 15%. This is the first study to concentrate on determining A1 and RA in rat plasma through oral administration.
    CONCLUSIONS: The liquid chromatography-tandem mass spectrometry method developed in this study offers a rapid, sensitive, and alternative approach for the accurate quantification and identification of RA and A1 in vivo. The findings serve as a significant foundation for evaluating the clinical applications of the medicine.
  15. Res Sq. 2023 Aug 03. pii: [Epub ahead of print]
    Pieter Dorrestein, Simone Zuffa, Robin Schmid, Anelize Bauermeister, Paulo Wender Portal Gomes, Andres Caraballo-Rodriguez, Yasin El Abiead, Allegra Aron, Emily Gentry, Jasmine Zemlin, Michael Meehan, Nicole Avalon, Robert Cichewicz, Ekaterina Buzun, Marvic Carrillo-Terrazas, Chia-Yun Hsu, Renee Oles, Adriana Vasquez Ayala, Jiaqi Zhao, Hiutung Chu, Mirte Kuijpers, Sara Jackrel, Fidele Tugizimana, Lerato Nephali, Ian Dubery, Ntakadzeni Madala, Eduarda Moreira, Leticia Costa-Lotufo, Norberto Lopes, Paula Rezende-Teixeira, Paula Jimenez, Bipin Rimal, Andrew Patterson, Matthew Traxler, Rita de Cassia Pessotti, Daniel Alvarado-Villalobos, Giselle Tamayo-Castillo, Priscila Chaverri, Efrain Escudero-Leyva, Luis-Manuel Quiros-Guerrero, Alexandre Bory, Juliette Joubert, Adriano Rutz, Jean-Luc Wolfender, Pierre-Marie Allard, Andreas Sichert, Sammy Pontrelli, Benjamin Pullman, Nuno Bandeira, William Gerwick, Katia Gindro, Josep Massana-Codina, Berenike Wagner, Karl Forchhammer, Daniel Petras, Nicole Aiosa, Neha Garg, Manuel Liebeke, Patric Bourceau, Kyo Bin Kang, Henna Gadhavi, Luiz Pedro de Carvalho, Mariana Silva Dos Santos, Alicia Pérez-Lorente, Carlos Molina-Santiago, Diego Romero, Raimo Franke, Mark Broenstrup, Arturo Vera Ponce De Leon, Phillip Pope, Sabina La Rosa, Giorgia La Barbera, Henrik Roager, Martin Laursen, Fabian Hammerle, Bianka Siewert, Ursula Peintner, Cuauhtemoc Licona-Cassani, Lorena Rodriguez-Orduña, Evelyn Rampler, Felina Hildebrand, Gunda Koellensperger, Harald Schoeny, Katharina Hohenwallner, Lisa Panzenboeck, Rachel Gregor, Ellis O'Neill, Eve Roxborough, Jane Odoi, Nicole Bale, Su Ding, Jaap S Sinninghe Damsté, Xueli Guan, Jerry Cui, Kou-San Ju, Denise Silva, Fernanda Silva, Gilvan da Silva, Hector Koolen, Carlismari Grundmann, Jason Clement, Hosein Mohimani, Kirk Broders, Kerry McPhail, Sidnee Ober-Singleton, Christopher Rath, Daniel McDonald, Rob Knight, Mingxun Wang.
      MicrobeMASST, a taxonomically-informed mass spectrometry (MS) search tool, tackles limited microbial metabolite annotation in untargeted metabolomics experiments. Leveraging a curated database of >60,000 microbial monocultures, users can search known and unknown MS/MS spectra and link them to their respective microbial producers via MS/MS fragmentation patterns. Identification of microbial-derived metabolites and relative producers, without a priori knowledge, will vastly enhance the understanding of microorganisms' role in ecology and human health.
  16. J Sep Sci. 2023 Aug 15. e2300449
      This study used reversed-phase liquid chromatography-tandem mass spectrometry and supercritical fluid chromatography-tandem mass spectrometry for determination of the stereoisomers of chlorfenvinphos and dimethylvinphos in tobacco. Tobacco samples were extracted and purified with a modified quick, easy, cheap, effective, rugged, and safe technique using spherical carbon. The performance of both methodologies was comprehensively compared in terms of methods validation parameters (separation efficiency, linearity, selectivity, recovery, repeatability, sensitivity, matrix effect, etc.). Under optimized conditions, the calibration curves of the stereoisomers of chlorfenvinphos and dimethylvinphos in the range of 10-500 ng/mL showed excellent linearity with R2 ≥  0.997 in both methods. The adequate recoveries of analytes from three different spiked tobaccos were obtained using reversed-phase liquid chromatography-tandem mass spectrometry (86.1-95.7%) as well as supercritical fluid chromatography-tandem mass spectrometry (86.5-94.0%). The relative standard deviations for spiked samples were all below 7.0%. Compared with supercritical fluid chromatography-tandem mass spectrometry, lower matrix effects and LODs can be obtained in reversed-phase liquid chromatography-tandem mass spectrometry.
    Keywords:  chlorfenvinphos; dimethylvinphos; reversed-phase liquid chromatography-tandem mass spectrometry; stereoselective separation; supercritical fluid chromatography-tandem mass spectrometry
  17. Methods Mol Biol. 2023 ;2712 149-156
      Ferroptosis is a form of regulated cell death that occurs due to abnormal lipid metabolism. Lipids, which have been identified in over 45,000 different molecular species, play essential roles in modulating basic life processes. The process of ferroptosis is highly reliant on various lipid species, with polyunsaturated fatty acids (PUFAs) playing a central role in driving this process. Recent advances in mass spectrometry-based lipidomics have led to a surge in studies on ferroptosis. To explore the mechanism of lipid homeostasis in ferroptosis, the development of lipidomics techniques is critical. Currently, liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) are the most widely used analytical techniques in lipidomics. These techniques offer deeper insights into the complex lipid mechanisms that underlie ferroptosis.
    Keywords:  Ferroptosis; Lipidomics; Mass spectrometry
  18. J Chromatogr A. 2023 Aug 16. pii: S0021-9673(23)00515-0. [Epub ahead of print]1707 464290
      An ion chromatography (IC)-tandem mass spectrometry (MS/MS) method to analyze nerve agent degradation products in human urine was developed. Six degradation products of conventional nerve agents and six Novichok agent degradation products were analyzed simultaneously despite their differences in hydrophilicity and acidity. Using ammonium regeneration solution improved the peak shapes greatly compared with the results obtained with the ordinary IC-MS/MS configuration. For urine samples, a simple pretreatment method of dilution with water and ultrafiltration was used. The detection limits of the nerve agent degradation products were sufficiently low (10-250 ng/mL) and the calibration curves showed acceptable linearity. Due to the absence of a derivatization step, throughput was higher than for our previous derivatization-liquid chromatography-MS/MS method.
    Keywords:  IC-MS/MS; Nerve agents; Novichok agents; Suppressor; Warfare agents
  19. Methods Mol Biol. 2023 ;2712 81-90
      Ferroptosis is a regulated form of cell death characterized by the accumulation of oxidized phospholipids, particularly oxidized phosphatidylethanolamines (PE), which serve as important biomarkers in the progression of various diseases. To facilitate the comprehensive investigation of ferroptosis in biological systems, we present a robust and versatile untargeted redox phospholipidomics method employing normal-phase liquid chromatography-mass spectrometry (LC-MS). This high-throughput technique enables the identification and quantification of dozens of oxidized phospholipid species in a single run, providing valuable insights into the molecular mechanisms underlying ferroptosis. It has been successfully applied to diverse biological samples, including human patients, animals, and cell cultures, and offers a powerful tool for investigating the roles of oxidized phospholipids in the development and progression of various diseases.
    Keywords:  Ferroptosis; Lipid peroxidation; Liquid chromatography-mass spectrometry; Oxidized phospholipid; Redox phospholipidomics
  20. J Chromatogr A. 2023 Aug 05. pii: S0021-9673(23)00498-3. [Epub ahead of print]1707 464273
      Improvements to the quantification of three white wine impact odorants 3-sulfanylhexan-1-ol, 3-sulfanylhexyl acetate, and 4-sulfanyl-4-methylpentan-2-one, and the non-volatile precursors from which they are released during fermentation, is of great interest to the wine science community. Recent reports of a "Quick, Easy, Cheap, Effective, Rugged and Safe" (QuEChERS) based method for the concurrent analysis of these thiols and their precursors via liquid chromatography tandem mass spectrometry (LC-MS/MS) has enabled the development of far simpler methods, as well as aligning these analyses with principles of green analytical chemistry. This current work reports the development and validation of a QuEChERS based LC-MS/MS method utilising a safer derivatising agent, 4,4'-dithiodipyridine, while greatly minimising the reagents involved and waste produced. We demonstrate that this new method compares favourably to the previously reported method with repeatability of 0.2-1.3%RSD and 0.4-5.2%RSD for precursors and free thiols. Further, the commercially available internal standard, 1-hexanethiol, used in previous analytical methods was compared to stable isotope labelled analogues of the analytes, with results suggesting that it may not be a reliable internal standard.
    Keywords:  3-sulfanylhexan-1-ol; 3-sulfanylhexan-1-ol precursors; Green analytical chemistry; LC-MS/MS; QuEChERS
  21. Biomed Chromatogr. 2023 Aug 19. e5720
      We developed and validated an assay utilizing a liquid chromatography-tandem mass spectrometry technique to quantify the KRAS inhibitor adagrasib in mouse plasma and seven tissue-related matrices. The straightforward protein precipitation technique was selected to extract adagrasib and the internal standard salinomycin from the matrices. Gradient elution of acetonitrile and water modified with 0.5% (v/v) ammonium hydroxide and 0.02% (v/v) acetic acid on a C18 column at a flow rate of 0.6 ml/min was applied to separate the analytes. Both adagrasib and salinomycin were detected with a triple quadrupole mass spectrometer with positive electrospray ionization in a selected reaction monitoring mode. A linear calibration range of 2-2,000 ng/ml of adagrasib was demonstrated during the validation. In addition, the reported precision values (intra- and inter-day) were between 3.5 and 14.9%, while the accuracy values were 85.5-111.0% for all tested levels in all investigated matrices. Adagrasib in mouse plasma was reported to have good stability at room temperature, while adagrasib in tissue-related matrices was stable on ice for up to 4 h (matrix dependent). Finally, this method was successfully applied to determine the pharmacokinetic profile and tissue distribution of adagrasib in wild-type mice.
    Keywords:  KRAS inhibitor; LC-MS/MS; adagrasib; bioanalysis; mouse matrices
  22. RSC Adv. 2023 Aug 04. 13(34): 24150-24161
      Ambient desorption/ionization mass spectrometry (ADI-MS) has been widely used for direct analysis of real samples without sample preparation or separation. Studies on the quantification of low molecular weight compounds in complex matrices with ADI-MS remain scarce. In this paper, we report the application of surface-assisted flowing atmospheric-pressure afterglow mass spectrometry (SA-FAPA-MS) for fast qualitative screening of electronic cigarette liquid (e-liquids) ingredients and direct quantification of nicotine. The quantification approach is rapid, uses a deuterated D4-nicotine standard spike, and does not require a preceding chromatography step or other methods to remove the complex sample matrix. Selected e-liquids were directly applied on thin-layer chromatography (TLC) plate surfaces (normal phase (NP) silica, reversed phase (RP) modified silica, cyano (CN) modified silica, and dimethyl (RP2) modified silica) after dilution and internal standard spiking. The plates served purely as sample carriers and no analyte separation was performed. Promising qualitative results were obtained, demonstrating the ability to detect nicotine alkaloids using this approach and the ability to differentiate e-liquids based on their flavor variations. In addition, dimethyl- (RP2-) and cyano-modified (CN-) silica surfaces were selected for quantification based on performance results of previous studies. It was shown that results were in high accordance with high-performance liquid chromatography (HPLC) experiments with lowest deviations <3% on dimethyl surfaces. Additional quantitative experiments including a certified reference material achieved equally satisfying results with lowest deviations of -1.1% from the certified nicotine content. For nicotine, detection limits down to the fmol range (96 fmol on CN and 20 fmol on RP2) were obtained. A detailed comparison of glass surfaces with functionalized surfaces showed that the functionalized surfaces were superior in terms of sample application reproducibility, mass spectra quality, sensitivity, and information density. Thus, functionalized thin-layer surfaces are considered promising tools for both qualitative and quantitative ADI-MS analysis of complex samples.
  23. ACS ES T Water. 2023 Aug 11. 3(8): 2407-2414
      Analytical limitations make it challenging to develop effective methodologies for understanding glyphosate-based herbicide levels in drinking water and groundwater. Due to their lack of chromophores and zwitterionic nature, glyphosate-based herbicides are difficult to detect using traditional methods. This paper offers a straightforward method for quantifying glyphosate, glufosinate, and aminomethylphosphonic acid (AMPA) via 9-fluorenylmethylchloroformate (FMOC-Cl) pre-column derivatization and analysis by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Method development was focused on optimizing the critical variables for optimal derivatization using a 24-factorial design. We found that complete derivatization significantly depends on the inclusion of borate buffer to create the alkaline conditions necessary for aminolysis. Ethylenediaminetetraacetic acid (EDTA) addition was critical to minimize metallic chelation and ensure reproducible retention times and peaks. However, EDTA concentrations ≥5% decreased peak intensity due to ion suppression. The FMOC-Cl concentration and derivatization time exhibited a direct proportional relationship, with the complete reaction achieved with 2.5 mM FMOC-Cl after 4 h. Concentrations of FMOC-Cl greater than 2.5 mM led to the formation of oxides, which interfere with the detection sensitivity and selectivity. Desirable results were achieved with 1% EDTA, 5% borate, and 2.5 mM FMOC-Cl, which led to complete derivatization after 4 h.
  24. J Chromatogr A. 2023 Aug 04. pii: S0021-9673(23)00503-4. [Epub ahead of print]1706 464278
      Despite the rapid development of liquid chromatography (LC) in recent decades, it remains a challenge to achieve the desired chromatographic separation of complex matrices using a single column. Multi-column LC techniques, particularly serially coupled column LC (SCC-LC), have emerged as a promising solution to overcome this challenge. While more attention has been focused on heart-cutting or comprehensive two-dimensional LC, reviews specifically focusing on SCC-LC, which offers advantages in terms of precision and facile instrumentation, are scarce. Here, our concerns are devoted to the progress summary regarding the instrumentation and applications of SCC-LC. Emphasis is placed on column selection aiming to enlarge peak capacity, selectivity, or both through the optimization of combination types (e.g. RPLC-RPLC, -RPLC-HILIC, and achiral-chiral LC), connection devices (e.g. zero dead volume connector, tubing, and T-type connector), elution program (i.e. isocratic or gradient) and detectors (e.g. mass spectrometer, ultraviolet detector, and fluorescence detector). The application of SCC-LC in pharmaceutical, biological, environmental, and food fields is also reviewed, and future perspectives and potential directions for SCC-LC are discussed. We envision that the review can give meaningful information to analytical scientists when facing heavy chromatographic separation tasks for complicated matrices.
    Keywords:  Mobile phase compatibility; Multi-column LC; Polarity-extended separation; Serial hyphenation
  25. Anal Biochem. 2023 Aug 10. pii: S0003-2697(23)00249-X. [Epub ahead of print]678 115284
      Galactosemia is a carbohydrate metabolism disorder often caused by galactose-1-phosphate uridyl transferase (GALT) deficiency. Detecting GALT deficiency involves measuring intra-erythrocyte enzyme activity. We aimed to create a robust liquid chromatography-mass spectrometry (LC-MS/MS) method to assess GALT activity in dried blood spot (DBS) samples. We validated this method and compared it to the fluorometric approach. We investigated the impact of K2EDTA and lithium heparin tubes on enzyme activity to identify the best sample collection tube. We also assessed the reaction-stopping method. The developed approach employed [13C6]-galactose-1-phosphate as a substrate and UDP-N-acetylglycosamine as an internal standard (IS). The mean ± SD value for GALT activity of DBS samples was determined as 6.37 ± 1.96 μmol/gHb/hour. The linear range was 0.4-50 μM (2.4-310% of normal) in the DBS method. The % coefficient of variation (%CV) values were less than 15 for intra-day and inter-day repeatability studies. Over 90% recovery was achieved in recovery studies, and no ion suppression from matrix was detected. DBS samples were quite stable for 31 days under different storage conditions. Enzyme activity results reported as <3.5 U/g Hb by fluorometric method, were quantitatively determined for even very low concentrations by LC-MS/MS method.
    Keywords:  Dried blood spot; GALT; LC-MS/MS; Newborn screening
  26. J Anal Methods Chem. 2023 ;2023 3116223
      Methyl 7,7'-dimethoxy-5'-(morpholinomethyl)-[4,4'-bibenzo[d][1,3] dioxole]-5-carboxylate methanesulfonate (IMM) is an innovative drug for the treatment of nonalcoholic fatty liver disease (NAFLD) owing to its high efficacy and low toxicity. In this study, five minor impurities (I, II, III, IV, and V) were identified and analyzed using spectroscopic evidence, chemical synthetic methods, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The impurities included hydrolysates and oxidation by-products extracted from both the drug in its final formulation and during synthesis. Toxicity prediction revealed potential carcinogenicity of impurity V containing an N-oxygen fragment. A reliable and selective HPLC method for the quantitative analysis of impurities I-IV and a sensitive HPLC-MS/MS method for potential genotoxic impurity V were developed and optimized. The methods were validated based on the International Council for Harmonization guidelines. Satisfactory linearity was obtained for the analytes over the range of 0.1-2.0 μg/mL for impurities I-IV and 0.3-30.0 ng/mL for impurity V, and in all cases, the fitting correlation coefficients exceeded 0.999. The obtained limits of detection values were 0.05 ng/mL and 0.005 μg/mL for impurity V and impurities I-IV, respectively. The precision and repeatability of the methods were less than 1.08% and 8.72% for each impurity. The recovery percentages of all impurities were in the range of 91.18%-111.27%, with the relative standard deviation of less than 3.69%. The greenness assessment of the HPLC method and the HPLC-MS/MS method were evaluated by using AGREE software with a score value of 0.72 and 0.68, respectively. The recommended procedures that were accurate, specific, and ecofriendly were applied to the existing active pharmaceutical ingredients of IMM, and they generated satisfactory results.
  27. Front Nutr. 2023 ;10 1227517
      Capsaicin is the main food active component in Capsicum that has gained considerable attention due to its broad biological activities, including antioxidation, anti-inflammation, anti-tumor, weight regulation, cardiac protection, anti-calculi, and diurnal-circadian regulation. The potent biological effects of capsaicin are intimately related to metabolic pathways such as lipid metabolism, energy metabolism, and antioxidant stress. Mass spectrometry (MS) has emerged as an effective tool for deciphering the mechanisms underlying capsaicin metabolism and its biological impacts. However, it remains challenging to accurately identify and quantify capsaicin and its self-metabolites in complex food and biological samples, and to integrate multi-omics data generated from MS. In this work, we summarized recent advances in the detection of capsaicin and its self-metabolites using MS and discussed the relevant MS-based studies of metabolic pathways. Furthermore, we discussed current issues and future directions in this field. In-depth studies of capsaicin metabolism and its physiological functions based on MS is anticipated to yield new insights and methods for preventing and treating a wide range of diseases.
    Keywords:  biological activities; capsaicin; food analysis; mass spectrometry; metabolic pathways