食品中甜蜜素气相色谱方法测定的研究

采用组校准数据处理方法,建立食品中甜蜜素(环己基氨基磺酸钠)准确定量气相色谱方法。甜蜜素在酸性介质中与亚硝酸钠反应生成环己醇亚硝酸酯,气相色谱法测定食品中甜蜜素发现,测定的反应产物有2个色谱峰,目前通常认为第一个峰为环己醇亚硝酸酯,第二峰为环己醇,并以第一峰作为主产物峰定量计算甜蜜素含量。但是主产物峰会随着时间和反应条件变化逐渐转变为副产物峰,试验发现用主峰进行定量造成检测结果极其不准确。通过大量试验数据与CNAS比对结果验证,采用主副产物峰面积之和进行数据处理,能准确测定食品中甜蜜素含量。甜蜜素在0.01～0.6mg/mL范围内线性关系良好,相关系数r=0.9995;该方法的检出限为0.005mg/mL,试样中5个添加水平回收率为97.4%～103.6%,方法精密度和准确度高,分离度好,能很好地避免样品中各种成分的干扰。

Determination of sodium cyclamate in food by gas chromatography

A group’s calibration capillary column gas chromatography method is established to quantify sodium cyclamate in food.Sodium cyclamate can react with sodium nitrite and produce cyclohexanol nitrite in acidic condition.There are two peaks in the chromatogram of the reaction products,the first peak(the main product peak) is cyclohexanol nitrite and the second one(the by-product peak) is cyclohexanol.Generally the first peak is used to give the content of sodium cyclamate.This will make the result inaccurate because gradually the main product peak will turn to the by-product peak.In this article the method is optimized by the group’s calibration,compared with CNAS both the main product peak and the by-product peak are used to give the content of sodium cyclamate.The results show that this method can give the content of sodium cyclamate accurately,the linearity of the calibration curve is very good in the range of 0.01～0.6 mg/mL,the correlation coefficient(R-square value) is 0.9995,the detection limit is 0.005 mg/mL,the recovery is 97.4%～103.6% when five additions are carried out.This method has good precision,accuracy and separation and can avoid the disturbing of other components.