固相微萃取-GC-MS定量检测白酒中两种异嗅物质

Quantification of Two Odor Components in Chinese Liquor by SPME-GC-MS

建立利用固相微萃取技术结合气相色谱-质谱联用法测定白酒中两种异嗅物质——二甲基二硫和二甲基三硫的方法,并对前处理的条件进行优化。结果表明,最佳前处理条件为：100μm PDMS萃取头、萃取温度50℃、萃取时间20 min、Na Cl添加量1.5 g、解吸时间5 min;该方法简便、快速,对于二甲基二硫（R2=0.999 1）和二甲基三硫（R2=0.999 5）具有良好的线性,其检出限分别为0.04μg/L和0.06μg/L,相对标准偏差均不高于3.98%,加标回收率在93.17%~112.07%之间。该方法适用于白酒中二甲基二硫和二甲基三硫两种异嗅物质的定量分析。

A method for the quantification of two odor components, dimethyl disulfide（DMDS） and dimethyl trisulfide（DMTS）, in Chinese liquor using headspace solid-phase micro extraction（SPME） coupled with gas chromatography-mass spectrometry（GC-MS） was established. Results indicated that the optimal pretreatment conditions were determined as follows： 100 μm PDMS extraction fiber, 20 min extraction at 50 ℃ after addition of 1.5 g of Na Cl, and 5.0 min desorption. The linear correlation coefficients for DMDS and DMTS were 0.999 1 and 0.999 5, respectively, and the limits of detection were 0.04 and 0.06 μg/L, respectively, with relative standard deviation（RSD） less than 3.98%. The average recovery rates for spiked samples were between 93.17% and 112.07%. The method established in the study is applicable to the determination of DMDS and DMTS in Chinese liquor.