离子色谱法测定乳粉中的高氯酸盐

Determination of Perchlorate in Milk Powder by Ion Chromatography

建立了乳粉中痕量高氯酸盐的固相萃取离子色谱分析方法。在碱性条件下,乙腈提取、浓缩,0.22μm尼龙滤膜+RP柱净化,AS20阴离子分析柱(150mm×4.0mm)分离,流动相为氢氧化钠溶液(30~70mmol/L),流速1.0mL/min。结果表明,高氯酸盐在0.4~20μg/L内具有良好的线性关系,相关系数0.999 8,样品检出限20μg/kg,加标回收率在77.2%~108%。测定了41个乳粉中的高氯酸盐含量,高氯酸盐检出率为31.7%。对质监部门用来检测乳粉中高氯酸盐的方法是一个补充,为食品安全提供了参考数据。

An ion chromatographic method was developed for the determination of perchlorate in milk powder. Sample was first extracted by acetonitrile under basic condition, then purified on an RP column after concentration and filtration, and finally separated on an AS20 column （150 mm ×4.0 mm） with the eluent of 30--70 mmol/L NaOH solution at the flow rate of 1.0 mL/min. Perchlorate concentration with conductivity showed good linearity in the range from 0.4 to 20 μg/L, with the correlation coefficient of 0. 999 8. The rate of recovery ranged from 77.2% to 108%, and limit of detection was 20 μg/kg. The method had been applied to determine perchlorate content in 41 milk powders and the detection rate of 31.7% was achieved.