毛细管气相色谱法测定牛奶中的甜蜜素

The Application of Capillary Gas Chromatography in Determination of Sodium Cyclamate in Milk

目的：研究用毛细管气相色谱法测定牛奶中甜蜜素含量的分析方法,通过对沉降剂用量、酯化时间等条件的优化,降低方法的检出限。方法：利用甜蜜素（环己基氨基磺酸钠）在硫酸介质中与亚硝酸钠反应后生成环己醇亚硝酸酯,用正己烷萃取,并用气相色谱检测环己醇亚硝酸酯的含量。结果：甜蜜素的线性范围为0.05-0.4 mg/mL,方法检出限为2μg,加标回收率在99.4%-102.5%之间,RSD为1.4%。结论：该方法简便、快捷、准确度高、重现性好,方法检出限低,优于GB/T5009.97-2003法的4μg检出限。

Objective： To study the analysis method of capillary gas chromatography in determination of sodium cyclamate content in milk and to lower the detection limit of the method by optimizing the settling agent dosage, esterification time and other conditions.Methods： Sodium cyclamate reacted in the medium of sulfuric acid with sodium nitrite and cyclohexanol nitrite was produced and extracted with n-hexane, and its content was determined by capillary gas chromatography. Results： Linear range was from 0.05 to 0.4 mg/mL, the detection limit was 2 μg, recovery of standard addition was 99.4%-102.5%, and RSD was 1.4%. Conclusion： The method was simple, rapid and accurate, with good reproducibility and low detection limit, much better than detection limit of 4 μg by GB/T5009.97-2003 method.