采用固相微萃取-气相色谱-质谱法分析啤酒中醛类化合物

建立了顶空固相微萃取-气相色谱-质谱(HS-SPME-GC-MS)结合邻-五氟苄基羟胺(PFBHA)衍生以测定啤酒中与老化味相关的13种醛类化合物的方法。样品前处理不同于文献报道的方法,衍生试剂直接加入到啤酒样品中,然后插入SPME装置,一步完成衍生和萃取过程。经优化的固相微萃取条件为:65μmPDMS/DVB萃取头,萃取温度50℃,萃取时间60min。GC-MS分析采用选择离子模式(SIM)并以内标法定量,所建方法的定量重复性较好,样品重复测定的RSD在2.5%-19.5%;回收率在55.3%-108.8%。在测定新鲜和老化啤酒时,显示出该方法具有较好的适用性。

Analysis of Aldehydes in Beer Using Headspace Solid Phase Microextraction with Gas Chromatography/Mass Spectrometry

A method for the determination of 13 stale-flavor aldehydes in beer was developed with o-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine(PFBHA) derivation by Headspace Solid Phase Microextraction (HS-SPME) and GC-MS analysis. Different from the former studies, derivation and extraction process were performed in one step as the deriving reagent was directly added in beer sample and SPME fiber was then exposed into the sample vial. The opti-mized SPME conditions were at 50℃ for 60min with 65um PDMS/DVB fiber. GC-MS analysis was achieved by SIM mode using E-2-heptenal as internal standard. The method was shown good repeatability with RSD between 2. 5%-19.5% and the recoveries were ranged from 55.3 to 108.8%. The method was successfully applied to fresh and aged beer with good applicability.