毛细管电泳法测定糖果及调制酒中10种人工合成色素

Simultaneous Determination of Ten Synthetic Food Colorants in Alcoholic Beverages and Candies by Capillary Electrophoresis

建立了糖果及调制酒中10种常用人工合成色素的毛细管电泳-二极管阵列检测新方法。以75μm×70 cm(有效长度60 cm)未涂敷石英毛细管为分离柱,25 min内实现了10种人工合成色素的同时分离与测定。分离电压18 kV,检测波长为214 nm。研究了影响10种人工合成色素分离的因素,如分离缓冲溶液的浓度、pH值及添加剂的浓度等。调制酒样品过膜后直接进样,粉碎后的糖果样品经提取液提取,离心后取上清液直接进样。10种人工合成色素的质量浓度分别在1.0~40.0、1.5~60.0、2.0~80.0、3.0~120.0 mg/L范围内与其对应的校正峰面积呈良好线性关系(r≥0.999 6)。检出限(RSN=3)在0.3~1.0 mg/L之间,定量限(RSN=10)在1.0~3.0 mg/L之间。方法回收率在92.1%~106.5%之间,相对标准偏差(n=5)在0.5%~4.4%之间。本方法简便、准确,适用于常规实验室中糖果及调制酒中常用10种人工合成色素的检测。

A new method for the simultaneous determination of ten synthetic food colorants in alcoholic beverages and candies by capillary electrophoresis(CE) with photodiode array(PDA) detection was established. The separation was carried out using an uncoated capillary with 75 μm(i.d.) and total length of 70 cm(60 cm to the detector) within 25 min. The separation voltage was 18 kV. The detection wavelength was set at 214 nm. The key factors that affect the separation such as the concentration and pH of the running buffer,the concentration of additives were investigated in detail. The alcoholic beverage was directly injected after filtration. The candy sample was first ground and then extracted with sample buffer. The extract was centrifuged and the supernatant could be directly injected. Good linear relationships between the corrected peak areas and mass concentrations of the ten synthetic food colorants were obtained in the range of 1.0–40.0,1.5–60.0,2.0–80.0,3.0–120.0 mg/L,respectively,with correlation coefficients all above 0.999 6. The limits of detection(RSN =3) were 0.3–1.0 mg/L,and the limits of quantitation(RSN =10) were 1.0–3.0 mg/L,respectively. The average recoveries were between 92.1%–106.5% with relative standard derivations of 0.5%–4.4%. This method is simple and accurate. It can be applied to the routine analysis of 10 synthetic colorants in alcoholic beverages and candies.