高效阴离子交换色谱-积分脉冲安培检测法测定原料乳中的硫氰酸钠

Determination of Sodium Thiocyante in Raw Milk by High Performance Anion Exchange Chromatography with Integrated Pulsed Amperometric Detection

建立了原料乳中硫氰酸钠的离子色谱-积分脉冲安培检测器分析方法。样品经无水乙醇沉淀蛋白，离心后经ENVI-18固相萃取小柱净化，采用IonPacAG21保护柱（50×2mm）和IonPacAs21分析柱（250×2mm）进行分离，在优化的安培检测波形条件下，硫氰酸钠在0．01～0．50mg／L浓度范围内与峰面积呈良好的线性关系，相关系数为O．9999，检出限为0．005mg／L。在1．00mg／kg和5．00mg／kg两个水平添加时的平均回收率分别为92．4％和105．0％，相对标准偏差分别为9．94％和6．79％。该方法灵敏度高、快速准确、经济环保，可用于原料乳样品中硫氰酸钠测定。

A new method for analysis of sodium thiocyanate in raw milk was proposed. Sodium thioeyanate was extracted from milk samples with anhydrous ethanol and cleaned-up by a ENVI-18 SPE column. The target analyte was separated on a Dionex IonPac AS21（250 × 2 mm） analytical column and IonPac AG21 （50 × 2 mm） guard column with 35 mmol/L sodium hydroxide, and detected by an integrated pulsed amperometric detector（IPAD）. The recoveries for the spiked level of 1.00 and 5.00 mg/kg were 92.4% and 105%, respectively, with relative standard deviations of 9.94% and 6.79%, respectively. The detection limit of the method was 0. 005 mg/kg（S/N=3）.