磺胺类人工合成甜味剂的毛细管电泳/电导法分离检测

采用15 mmol/L Tris-10 mmol/L H3BO3-0.2 mmol/L EDTA为电泳运行液,0.2%四乙烯五胺为电渗流抑制剂,融硅石英毛细管(45 cm×50 μm),负高压分离(-15 kV),柱端接触式电导检测,建立了磺胺类人工合成甜味剂(糖精钠、安赛蜜、甜蜜素)的高效毛细管电泳/电导法分离检测方法.糖精钠、安赛蜜、甜蜜素的线性检测范围分别为0.8 ～120、1.1 ～120、1.5 ～120 μmol/L,检出限分别为0.3、0.4、0.6 μmol/L.详细讨论了电泳运行液的组成、浓度以及进样方式对灵敏度和分离度的影响.该法用于市售饮料中3种甜味剂的分离检测,结果满意.

Separation and Determination of Sulfanilamide Artificial Sweeteners in Beverages by Capillary Electrophoresis with Conductivity Detection

A new method for the rapid separation and sensitive determination of sulfanilamide artificial sweeteners,including saccharin sodium,acesulfame potassium and sodium cyclamate,by capillary electrophoresis with conductivity detection was developed.The optimum conditions were as follows:running buffer:15 mmol/L Tris-10 mmol/L H3BO3-0.2 mmol/L EDTA,electrocsmotic flow(EOF) inhibitor:0.2% tetraethylenepentamine,separation voltage:-15 kV,electrokinetic injection:-10 kV×10 s.Three analytes could be well separated within 11 min in a fused-silica capillary under the optimal conditions.The linear response ranges were 0.8-120,1.1-120,1.5-120 μmol/L with the LODs of 0.3,0.4,0.6 μmol/L for saccharin sodium,acesulfame potassium and sodium cyclamate,respectively.The relative standard deviations for the intra- and inter- day precisions were below 4.0%.Effects of the component of the running buffer and its concentration,and the injection mode on the sensitivity and separation for the method were discussed in detail.The established method was used to determine the analytes contents in different commercial beverages with satisfactory results.