气相色谱-质谱联用法分析粪便中碱性和中性挥发性代谢产物

建立了一种快速分析人和大鼠粪便中碱性和中性挥发性代谢产物的气相色谱-质谱联用法(GC-MS).粪便样品采用75%甲醇溶液提取,加入氨水,使溶液中氨水的终浓度为1%(pH=10)后,GC-MS检测分析.采用CP-Sil 5毛细管柱(25 m × 0.25 mm × 0.12 μ);载气: 高纯氦气,流速1 mL/min;程序升温;使用电子轰击(EI)离子源,电子能量:-70 eV;进样口温度: 220℃,离子源温度: 230℃,传输线温度: 280℃;电子倍增器电压: 0.95 kV,全扫描模式,扫描范围: m/z 10~600;溶剂延迟: 3 min.通过检索NIST标准谱库,采用对照品比对及质谱数据解析的方法,在人的粪便样品中检测到11种碱性和中性挥发性代谢产物,在大鼠的粪便样品中检测到7种碱性和中性挥发性代谢产物.本方法处理过程简单,灵敏度高,适用于人和大鼠粪便中碱性和中性挥发性代谢产物的快速分析.

Analysis of Alkaline and Neutral Volatile Metabolites in Fecesby Gas Chromatography-Tandem Mass Spectrometry

A rapid gas chromatography-tandem mass spectrometric (GC-MS) method was developed for the analysis of alkaline and neutral volatile metabolites of human and rat feces.Feces were extracted by 75% (V/V) methanol solution.After addition of ammonia solution (pH 10, final concentration of 1%), the supernatant was subjected to GC-MS analysis.In the experiment, a CP-Sil 5 (25 m × 0.25 mm × 0.12 μm) capillary column was utilized to separate the interesting compounds.Helium was employed as a carrier gas at a constant flow rate of 1 mL/min.Oven temperature was programmed as follows: the initial temperature was set at 50℃ and held for 1 min, then increased at 25℃/min to 150℃, sustained for 1 min;increased at 20℃/min to 200℃, held for 2 min;and finally increased at 10℃/min to 270℃, maintained for 5 min.The MS was operated in the electron impact ionization mode at -70 eV.The injector, ion source and transfer line temperatures were maintained at 220℃, 230℃ and 280℃, respectively.Mass data were acquired in full scan mode from m/z 10 to 600.The solvent delay time was set for 3 min.A total of 11 volatile components were identified in the feces from human and 7 in the feces from rats by retrieving the NIST library, comparing with the standards and analyzing the MS data.The method was simple and sensitive in the detection of alkaline and neutral volatile metabolites of feces from human and rats.