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Start Over Topic lc-ms/ms Journal analytical and bioanalytical chemistry Publisher springer berlin heidelberg
217 results

2. Sensitive and quantitative determination of short-chain fatty acids in human serum using liquid chromatography mass spectrometry

Author

David Broadhurst, Nathan G. Lawler, Armaghan Shafaei, Mary C. Boyce, Veronica Vamathevan, and Jessica Pandohee

Subjects
Serum, High-resolution mass spectrometry, Chromatography, Chemistry, Reproducibility of Results, Mass spectrometry, SCFA, Fatty Acids, Volatile, Biochemistry, Sensitivity and Specificity, Quantitative determination, Mass Spectrometry, Analytical Chemistry, Chromatographic separation, Liquid chromatography–mass spectrometry, Lc ms ms, Humans, Gas chromatography, LC-MS/MS, Volume concentration, Blood Chemical Analysis, Research Paper, Chromatography, Liquid
Abstract

Short-chain fatty acids (SCFAs) are increasingly being monitored to elucidate the link between gut health and disease. These metabolites are routinely measured in faeces, but their determination in serum is more challenging due to their low concentrations. A method for the determination of eight SCFAs in serum is described here. High-resolution mass spectrometry and gas chromatography were used to identify the presence of isomeric interferences, which were then overcome through a combination of chromatographic separation and judicious choice of MS fragment ion. The SCFAs were derivatised to form 3-nitrophenylhydrazones before being separated on a reversed-phase column and then detected using liquid chromatography tandem mass spectrometry (LC-QQQ-MS). The LODs and LOQs of SCFAs using this method were in the range 1 to 7 ng mL−1 and 3 to 19 ng mL−1, respectively. The recovery of the SCFAs in serum ranged from 94 to 114% over the three concentration ranges tested. Supplementary Information The online version contains supplementary material available at 10.1007/s00216-021-03589-w.

Published
2021

4. Development and bioanalytical method validation of an LC-MS/MS assay for simultaneous quantitation of 2-alkyl-4(1H)-quinolones for application in bacterial cell culture and lung tissue

Author

Catherine B. Blackwood, Mariette Barbier, Maureen A. Kane, Amanda G. Oglesby-Sherrouse, Luke K. Brewer, and Jace W. Jones

Subjects
Male, Bioanalysis, 2-Alkyl-4(1H)-quinolones, 02 engineering and technology, Quinolones, medicine.disease_cause, Mass spectrometry, 01 natural sciences, Biochemistry, Bacterial cell structure, Analytical Chemistry, Mice, Tandem Mass Spectrometry, Lc ms ms, medicine, Animals, LC-MS/MS, Lung, Alkyl, chemistry.chemical_classification, Chromatography, Pseudomonas aeruginosa, Chemistry, 010401 analytical chemistry, Bacterial, Reproducibility of Results, 021001 nanoscience & nanotechnology, 0104 chemical sciences, Linear range, Cell culture, Female, 0210 nano-technology, AQs, Research Paper, Chromatography, Liquid
Abstract

Pseudomonas aeruginosa is an opportunistic pathogen that produces numerous exoproducts during infection that help it evade the host immune system and procure nutrients from the host environment. Among these products are a family of secreted 2-alkyl-4(1H)-quinolone metabolites (AQs), which exhibit a range of biological activities. Here, we describe the validation of a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for quantifying multiple AQ congeners in complex biological matrices. The assay was validated for selectivity, sensitivity, linearity, accuracy, precision, carryover, dilution integrity, recovery, matrix effects, and various aspects of stability (freeze-thaw, bench-top, long-term storage, and autosampler/post-preparative). Using authentic standards for 6 distinct AQ congeners, we report accurate quantitation within a linear range between 25 and 1000 nmol/L for all of the validated AQ standards. This method was successfully applied to quantify AQ concentrations in P. aeruginosa cell culture and in the lungs of mice infected with P. aeruginosa. Further, we confirmed the presence of unsaturated forms of several AQ congeners in cell culture. Graphical abstract Electronic supplementary material The online version of this article (10.1007/s00216-019-02374-0) contains supplementary material, which is available to authorized users.

Published
2020