顶空-毛细管气相色谱法测定葡萄酒中的甲醇

Determination of Methanol in Wine by Head Space GC with Capillary Column

摘要:

本文对炉温、保温时间、气液相比和盐析试验4个方面对测定葡萄酒中甲醇的顶空—毛细柱气相色谱法进行摸索，确定最优的顶空气相色谱分析条件为：以ZB-WAX毛细柱为分析用色谱柱，分流进样(分流比20:1、2 mm分流衬管)；载气流速2.0 mL/min；炉温70 ℃；保温时间15 min；测定液5 mL；不加盐析剂，FID为检测器。方法在甲醇浓度范围10.2~407.6 mg/L之间线性良好，r=0.9997；平均回收率99.2%，样品重现性RSD为1.4%，检出限为8.5 mg/L，本方法与国标GB/T 15038-2006方法相比简便、高效，测定结果可靠。

Abstract:

In this paper, through four factors such as temperature, time, the ratio of gas-liquid phase and salting out, the determination of methanol in wine by head space GC with capillary column was studied and the optimal conditions were found as following: using a Phenomenex ZB-WAX chromatographic column and a FID detector. The split ratio was 20 with split liner tube (2mm I.D) and the flow rate of carrier gas was 2.0 mL/min. The heated temperature was 70℃ with head space sampling used and vial equilibration time was 15 min and sample volume was 5 mL in a 20mL vial. The linear of this method was satisfied when the concentration of methanol was at the range of 10.2~407.6 mg/L (r=0.9997). The lowest method detection limit was 8.5 mg/L and the average recovery rate was 99.2%. RSD of Repeat was 1.4%. It was shown that this method is more simple and efficient than GC method in GB/T15038-2006, and the result was reliable.