液相色谱-串联质谱联用法测定食品中三聚氰胺残留量

Determination of Residual Amount of Melamine in Foodstuffs by Hyphenation of Liquid Chromatography and Mass Spectrometry in Tandem

提出了液相色谱-串联质谱联用法测定动物源性食品中三聚氰胺残留量的方法。样品采用乙腈进行提取,饱和氯化钠溶液进行分配经反相色谱分离后,串联质谱法进行测定,同位素内标法进行定量,方法的测定下限(10S/N)为0.05 mg·kg^(-1),以5类食品样品为基体,加入4种不同浓度水平的三聚氰胺标准作回收试验,测得回收率在72.9$～104.1%之间,测定值的相对标准偏差(n=6)在4.7%～15.2%之间。

It was reported that residual amount of melamine in foodstuffs of animal origin was determined by LC-MS/MS. Melamine was separated from the sample, in which standard melamine labelled with 15N3 was added as internal standard, by extraction with acetonitrile and partitioned with saturated sodium chloride solution. After centrifugation, an aliquot of the supernatant was taken for separation by reverse phase liquid chromatography and the content of melamine was determined by MS/MS. Lower limit of determination （10S/N） of the method was found to be 0. 05 mg ·kg -1. Tests for recovery were made by addition of standard melamine at 4 different concentration levels to 5 kinds of foodstuffs as matrixes, values of recovery found were in the range of 72. 9%- 104. 1% , with values of RSD＇s （n=6） in the range from 4. 7% to 15.2%.