A Gas Chromatographic Analysis of Fecal Short-Chain Fatty Acids, Using the Direct Injection Method

✍ Scribed by Albert Tangerman; Fokko M. Nagengast

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 104 KB
• Volume: 236
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1006/abio.1996.0123

✦ Synopsis

techniques to measure fecal SCFA concentrations are A simple, reproducible, and rapid gas chromatorather cumbersome and time-consuming. Most procegraphic method for short-chain fatty acid determinadures involve some kind of pretreatment of the fecal tion in human feces was developed. It involves direct samples followed by gas chromatography (GC). Feces injection of fecal supernatants into the gas chromatohave been pretreated by extraction in organic solvents graph, without any pretreatment. Contamination of (9-11), ultrafiltration (12, 13), and derivatization (14, the gas chromatographic column with nonvolatile fe-15), steam distillation ( 16), and vacuum distillation (3, cal material was prevented by the use of a glass liner [17][18][19]. At present, the latter method of vacuum disin the injector. This liner, which acted as a precolumn, tillation followed by GC of the aqueous SCFA solutions was stoppered with a glass wool plug at the lower end is used most often. Although GC on capillary columns of the liner. Injection was performed against the glass has been used more and more, GC on packed columns wall of the liner, ensuring an immediate contact of the is still the method of choice for the separation of fecal injected sample with the hot glass wall. More than 100 SCFA. In addition to GC, high-performance liquid chroinjections of fecal supernatants could be carried out matography has also been applied to the analysis of before the liner had to be replaced by a new one. Peak fecal SCFA (13,20). A major drawback of the abovetailing and ghosting was prevented by the use of formentioned methods is the time-consuming pretreatmic acid in the fecal samples. The method gave sharp ment procedures, e.g., for the vacuum distillation techpeaks with baseline separation for all the fatty acids.