顶空气相色谱法测定新面醑中甲醇量

Determination of the Content of Methanol in Xinmian Xu by Headspace Gas Chromatography

目的建立顶空气相色谱法(headspace gas chromatography,HS-GC)测定新面醑中甲醇量。方法气相模块:气相色谱柱(Agilent DB-624,30 m×0.53 mm,3μm),设定柱温条件为程序升温(0→8 min,50℃;8→13 min,50→65℃;13→18.4 min,65→200℃,18.4→28.4 min,200℃),进样口温度为200℃,N_(2)载气,色谱柱流量为3 ml/min,火焰离子化检测器(flame ionization detector,FID)温度为220℃,氢气流量和空气流量分别为30 ml/min和300 ml/min,分流比为30∶1。顶空模块:加热箱、定量环、传输线温度分别为85℃、95℃和110℃,样品平衡时间、循环时间分别为20 min和40 min,进样体积为1 ml。结果甲醇在0.0005%~0.1%ml/ml线性关系良好,y=2832.30x+0.48(R^(2)=0.999);加样回收率≥98.55%,相对标准偏差(relative standard deviation,RSD)≤1.39%;中间精密度RSD为0.89%。结论本研究建立了HS-GC测定新面醑中甲醇量,具有良好的线性和准确性,适用于新面醑中甲醇量的测定。

Objective To establish a method for determining the content of methanol in Xinmian Xu by headspace gas chromatography.Methods The part of gas chromatograph:gas chromatographic column(Agilent DB-624,30 m×0.530 mm,3μm)and the column temperature was programmed(0→8 min,50℃;8→13 min,50→65℃;13→18.4 min,65→200℃;18.4→28.4 min,200℃),the injector temperature was 200℃,N_(2) was the carries gas and the flow rate was 3 ml/min,the temperature of flame ionization detector(FID)was 220℃,the flow rate of H_(2) and air were 30 ml/min and 300 ml/min,respectively,the split ratio was 30∶1.The part of headspace:the temperature of heating box,quantitative ring and transmission line were 85℃,95℃,and 110℃,respectively,the balance time of samples and cycle time were 20 min and 40 min,respectively,the injection volume was 1 ml.Results Methanol has a good linear relationship in 0.0005%~0.1%ml/ml,y=2832.30x+0.48(R^(2)=0.999);the sample recovery rate was≥98.55%,and the relative standard deviation(RSD)was≤1.39%;the RSD of median precision was 0.89%.Conclusion A method for determining the content of methanol in Xinmian Xu has been developed in this study,it has good linearity and accuracy and can be used to determine the content of methanol in Xinmian Xu.