气相色谱内标法测定白酒中甲醇含量

Determination of methanol in liquor by internal standard method of gas chromatography

中文关键词:  气相色谱法  内标法  白酒  甲醇

英文关键词:gas chromatography  internal standard method  liquor  methanol

中文摘要:

      目的 建立气相色谱内标法测定白酒中甲醇含量的方法。方法 选择色谱柱为HP-INNOWAX石英毛细管柱, 载气为氮气, 流速为2.0 mL/min。检测器为火焰离子化检测仪(flame ionization detector, FID), 温度为250 ℃; 进样口温度为200 ℃;分流比为5:1; 采用液体直接进样, 溶剂为40%(V/V)乙醇, 内标物质为叔戊醇。结果 被测物甲醇和内标物质叔戊醇均能得到很好的分离,空白溶剂无干扰; 在线性范围100.9~ 1008.6 mg/L内, 方法线性方程为Y=0.002155X+0.012511, 相关系数为0.9999; 方法检出限为5.0 mg/L、定量限为16.7 mg/L; 平均回收率分别为96.8%~99.6%, 相对标准偏差(relative standard deviation, RSD)不超过0.45% 结论 方法操作简单, 进样时间短, 数据准确, 重复性好, 适用于白酒中甲醇含量的检测。

英文摘要:

      Objective To develop a method for determination of methanol in liquor by internal standard method of gas chromatography. Methods HP-INNOWAX quartz capillary column was chosen as the chromatographic column, and the carrier gas was nitrogen, with the 2.0 mL/min flow rate. The detector was flame ionization detector(FID) and the temperature was 250 ℃; The inlet temperature was 200 ℃ and the split ratio was 5:1. The sample was directly injected by liquid, the solvent was 40%(V/V) ethanol, and the internal standard material was tert-amyl alcohol. Results Both the test substance methanol and the internal standard substance tert-amyl alcohol were well separated without the interference from blank control. In the linear range of 100.9-1008.6 mg/L, the linear equation of the method was Y=0.002155X+0.012511, with a correlation coefficient 0.9999. The detection limit was 5.0 mg/L and the quantitative limit was 16.7 mg/L. The average recoveries were 96.8%-99.6%, and the relative standard deviation (RSD) no more than 0.45%. Conclusion The method has the advantages of simple operation, short injection time, accurate data, and good repeatability and can be used for the determination of methanol content in liquor.