Determination of short chain fatty acid by capillary zone electrophoresis

• Main Authors: Szu-Yu Lai, 賴思羽
• Other Authors: Young-Chong Chang
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/86549144410785434509

碩士 === 國立宜蘭大學 === 食品科學系碩士班 === 98 === Short-chain fatty acids (SCFAs) are organic fatty acids with 2 to 6 carbon atoms. SCFAs have attracted much attention recently because of their positive physiological effects. SCFAs can be used to as indicator for intestinal health with regard to they can lower colonic pH, which is thought to protect against cancer of the colon by reducing the bioavailability of toxic amines. Therefore, it is necessary to development high efficiently quantitative method for SCFAs. Capillary electrophoresis is a well-developed technology for materials separation in the past few years. By capillary electrophoresis, the analytes have different moving velocity due to different charge to mass ratio under applied electric field, therefore the separation was achieved. This technology has some advantages, such as having high separating efficiency, shorting analytic time, few samples and chemicals are needed, having good reproducibility, and easily operation. In this research, capillary zone electrophoresis(CZE) was used to build up a analysis method to determine SCFAs. SCFAs have (almost) no UV absorption. Therefore, the developed CZE method for quantification was based on indirect UV detection. The proposed conditions: fused-silica capillary (100 cm, 76 m I.D.); buffer, 15 mM benzoate and 0.5 mM CTAB(N-Cetyl-N,N,N-trimethyl ammonium bromide), pH 11.0; voltage -20 kV; detected wavelength, 226 nm; temperature 25℃. The developed method was successfully applied to determine the SCFAs (acetate, propionate, n-butyrate, i-butyrate, valerate). As a result, the linear range of SCFAs is 0.01–3.0 mM（R2 = 0.9987–0.9999）, limit of detection 5–10 M, recovery 100.1–102.2%, reproducibility(coefficient of variation) 0.76%–2.11%. The analysis of real samples of chyme and dairy products(cheese, sheep milk, cream, condensed milk) was performed. The established GC method was applied to evaluate the CZE method, and compatible results were obtained.