摘要
优化了反相高效液相色谱测定奶粉中三聚氰胺的方法。样品制备:采用乙酸铅对奶粉中的蛋白质进行沉淀,用1%的三氯乙酸代替水对阳离子交换固相萃取柱进行活化和洗涤;色谱条件:提高缓冲离子对试剂pH值为3.0,增加流动相中乙腈比例。结果:用外标法定量分析,标准曲线的相关系数为0.9997,平均回收率为95.8%～101.5%。证明优化后的方法具有较好的回收率和重现性,可以准确地测定奶粉中的三聚氰胺。
The RP-HPLC method for determining melamine in milk powder has been developed. However, the differences in chromatography instrument and column performance and status may lead to the occurrence of disagreement among determination results from different labs. To enhance the accuracy, reproducibility and efficiency of melamine detection by HPLC, sample preparation and chromatographic conditions were optimized in the present study. Milk powder samples were extracted using 1% trichloroacetic acid and 2% lead acetate solution in an ultrasonic field and cleaned up on an SCX solid phase extraction column which was activated and leached using 1% trichloroacetic acid instead of water. The optimization of chromatographic conditions was achieved by increasing the ion-pairing buffer containing 10 mmol citric acid and 10 mmol heptane- 1-sulfonic acid sodium salt to pH 3 and adjusting the proportion of acetonitrile in the mobile phase consisting of it and the ion-pairing buffer to 28% （V/V）. The external standard method was adopted for the quantitative analysis of melamine. The correlation coefficient of linear equation was 0.9997 and the limit of detection of melamine was 0.15 mg/kg by this method. The recoveries for melamine in blank milk powder spiked at five levels were within 95.8%- 101.5 %. The optimized method has high reproducibility and allows accurate detection and high recovery for melamine in milk powder.
出处
《食品科学》
EI
CAS
CSCD
北大核心
2009年第14期227-229,共3页
Food Science
