Simultaneous quantification of straight-chain and branched-chain short chain fatty acids by gas chromatography mass spectrometry

Abstract

Biomedical research in areas such as metabolic disorders, neuromodulatory, and immunomodulatory conditions involves lipid metabolism and demands a reliable and inexpensive method for quantification of short chain fatty acids (SCFAs). We report a GC-MS method for analysis of all straight-chain and branched-chain SCFAs using pentafluorobenzyl bromide (PFBBr) as derivatization reagent. We optimized the derivatization and GC-MS conditions using a mixture containing all eight SCFA standards, i.e., five straight-chain and three branched-chain SCFAs. The optimal derivatization conditions were derivatization time 90 min, temperature 60 °C, pH 7, and (CH)CO:HO ratio 2:1 (v:v). Comparing the performance of different GC column configurations, a 30 m DB-225ms hyphenated with a 30 m DB-5ms column in tandem showed the best separation of SCFAs. Using the optimized experiment conditions, we simultaneously detected all SCFAs with much improved detection limit, 0.244-0.977 μM. We further applied the developed method to measure the SCFAs in mouse feces and all SCFAs were successfully quantified. The recovery rates of the eight SCFAs ranged from 55.7% to 97.9%.

Alterations in the gut microbiota and metabolite profiles of thyroid carcinoma patients

“…Decreased levels of SCFA lead to increased colonocyte death and increased cell turnover and may partially explain the 3.two‐fold higher lifetime risk of CRC observed in patients with Crohn's disease (CD) . However, propionic acid and butyric acid were not identified in our fecal metabolomics study, likely due to the inability to detect low concentrations or metabolite detection platform is unsuitable …”

“…50 However, propionic acid and butyric acid were not identified in our fecal metabolomics study, likely due to the inability to detect low concentrations or metabolite detection platform is unsuitable. 51 All bacteria from the Enterobacteriaceae family (including Klebsiella and Escherichia coli) are considered pathogenassociated molecular pattern (PAMP)-producing bacteria and were increased in the microbiota of TC patients. 52 These bacteria were also enriched in breast cancer, CRC and AITD.…”

Determination of Short-Chain Fatty Acids in Mouse Feces by High-Performance Liquid Chromatography Using 2-Nitrophenylhydrazine as a Labeling Reagent

“…Recently, for the determination of SCFAs in feces, gas chromatography with mass spectrometric detection (GC-MS) [17][18][19][20][21] or flame ionization detection (GC-FID) 22) and HPLC with mass spectrometric detection (HPLC-MS), [23][24][25][26] UV-visible spectrophotometric detection (HPLC-UV-Vis), 27) or electrochemical detection (HPLC-ECD) 28) have been reported. In these GC methods, mass spectrometry (GC-MS) and GC-FID are used for determination SCFAs in feces.…”

GC×GC-MS and parallel 2DLC-MS based untargeted metabolomics.

“…For instance, metabolites can be polar or non-polar, as well as organic or inorganic compounds. 3,4,5 These differences in chemical diversity have profound implications in metabolomics. As the chemical diversity of the metabolome is so broad, the analytical technologies needed to isolate and identify thousands of chemically distinct metabolites are inherently complex.…”

“…33,129,130 Therefore, additional information such as retention index must be used to reduce the rate of false identifications. 131,132 On average, retention index matching removed about 8.9% of false identifications generated by mass spectrum matching (Table 5.2). Overall, only about However, the percentage of assignment was dramatically reduced to only 1.1% to 1.8%…”