胶束在线扫集毛细管电泳法测定三聚氰胺

研究胶束在线扫集毛细管电泳法测定三聚氰胺的可行性,结果表明,与区带毛细管电泳相比,胶束在线扫集毛细管电泳法富集倍数提高约60倍。缓冲体系为140 mmol/L SDS+20 mmol/L NaH2PO4(pH 2.20)+10%(体积分数)甲醇,分离电压-18 kV,进样时间30 s,测量波长214 nm。考察了SDS浓度、pH、进样时间、运行电压等因素对分离测定的影响情况。在优化条件下,三聚氰胺在9 min时出峰,峰面积RSD≤3.7%。方法检出限、线性范围、相关系数分别为:0.13μg/mL、0.50~32.0μg/mL、0.9997。方法可用于奶粉中三聚氰胺的分离测定。

Determination of melamine in powdered milk by on-line sweeping micellar electrokinetic chromatography

On-line sweeping micellar electrokinetic chromatography(sweeping-MEKC) and capillary zone electrophoresis(CZE) were used for the determination of melamine.Compared to CZE,the sensitivity was improved about 60 times by sweeping-MEKC.The buffer medium contains 140 mmol/L SDS+20 mmol/L NaH2PO4(pH 2.20)+10% methanol,separation voltage was-18 kV,sample injection time was 30 s,and the samples were detected at 214 nm.The effect of SDS concentration,pH in background solution,sample injection time and applied voltag...