气相色谱法测定食用酵素产品中乙醇含量

Determination of ethanol content in edible Jiaosu products by gas chromatography

目的建立气相色谱法测定食用酵素产品中乙醇含量,为完善酵素检测方法标准提供技术支撑。方法称取2 g食用酵素产品,加入超纯水定容至20 mL,涡旋混匀1 min,以8000 r/min离心5 min,经0.22μm滤膜过滤后上机测定。结果乙醇含量的保留时间为7.765 min,在0.2~6.0 g/L范围内线性关系良好,相关系数为1.0000;对10种酵素样品重复测定5次,所得相对标准偏差(relative standard deviations,RSDs)在0.02%~1.46%之间,3个平行样品在0.0024、0.2000、5.0000 g/L的添加水平下回收率在95.5%~102.5%之间。方法的检出限低至2.4 mg/L。采用该法分析10种食用酵素产品中的乙醇含量,结果表明,60%的酵素产品中乙醇含量>0.5 g/100 g,超出QB/T 5323—2018《植物酵素》的要求。结论该法简便快捷、精密度和准确度高,适用于食用酵素产品中乙醇含量的测定。

Objective To establish a method for the determination of ethanol content in edible Jiaosu products by gas chromatography,and provide technical support for improving the standards of Jiaosu detection methods.Methods Two grams of edible Jiaosu product was weighed,fixed in volume to 20 mL by adding ultra pure water,vortex mixed for 1 min,centrifuged at 8000 r/min for 5 min,and filtered through a 0.22μm filter membrane before being measured on the computer.Results The retention time of ethanol was 7.765 min,and the linear relationship was good within the range of 0.2-6.0 g/L,with the correlation coefficient of 1.0000;the determination of the 10 kinds of Jiaosu samples was repeated 5 times,and the obtained relative standard deviations(RSDs)were within 0.02%-1.46%,the recoveries of the 3 parallel samples at the addition levels of 0.0024,0.2000 and 5.0000 g/L were within 95.5%-102.5%.The limit of detection for the method was as low as 2.4 mg/L.The method was applied to analyze the ethanol content in 10 kinds of edible Jiaosu products,the results showed that the ethanol content in 60%Jiaosu products was more than 0.5 g/100 g,which exceeded the requirements of QB/T 5323—2018 Plant Jiaosu.