顶空气相色谱法测定新面醑中乙醇浓度

Determination of Ethanol in Xinmian Xu by Head Space-gas Chromatography

目的建立顶空气相色谱法(head space-gas chromatography,HS-GC)测定新面醑中乙醇浓度。方法采用Agilent DB-624型色谱柱(30 m×0.53 mm,3.0μm),柱温为程序升温(起始温度为40℃,维持2 min,以每分钟3℃的速率升温至65℃,再以每分钟25℃的速率升温至200℃,维持10 min),进样口温度200℃,N载气,柱流速为4 ml/min,火焰离子化检测器(flame ionization detector,FID)温度220℃,H流量30 ml/min,空气流量300 ml/min。顶空加热箱温度85℃,定量环温度95℃,传输线温度110℃,样品平衡时间20 min,进样体积1 ml,分流比30∶1。结果乙醇在1×10^(-3)%~8×10^(-2)%(ml/ml)线性关系良好,Y=50.4118X-0.0011(R^(2)=1.0000);检测限和定量限分别是5×10^(-5)%和1×10^(-4)%(ml/ml);加样回收率≥94.40%,相对标准偏差(relative standard deviation,RSD)≤1.37%;中间精密度RSD为1.10%。结论本文建立了HS-GC测定新面醑中乙醇浓度,具有良好的专属性、线性、检测器灵敏度和准确度,适用于新面醑中乙醇浓度的测定。

Objective To establish head space-gas chromatography(HS-GC)to determine the concentration of ethanol in Xinmian Xu.Methods Agilent DB-624 column(30 m×0.53 mm,3.0μm)was used,and the column temperature was programmed(the initial temperature was 40℃and maintained for 2 minute,then increased to 65℃at the speed of 3℃/min,then to 200℃at the speed of 25℃/min for 10 minute),the sample inlet temperature was 200℃,Ncarried gas and the flow rate was 4 ml/min.The flame ionization detector(FID)temperature was 220℃,the flow rate of Hwas 30 ml/min,air flow was 300 ml/min.The temperature of the head-space heating was 85℃,the temperature of quantitative ring was 95℃,the temperature of transmission line was 110℃,the balance time of samples was 20 minute,the injection volume was 1 ml,and the split ratio was 30∶1.Results The linear range of ethanol at 1×10%-8×10%(ml/ml)was great,Y=50.4118X-0.0011(R~2=1.0000).The limits of detection and quantitation were 5×10%and 1×10%(ml/ml)respectively;the sample recovery rate was≥94.40%,and the relative standard deviation(RSD)≤1.37%;the RSD of median precision was 1.10%.Conclusion A method for determining the concentration of ethanol in Xinmian Xu has been developed.This method has good specificity,linearity,detector sensitivity and accuracy,which can be used to determine the concentration of ethanol in Xinmian Xu.