婴幼儿配方乳粉中甲醛的测定及实验室间协同验证

Determination of Formaldehyde in Infant Formula Milk Powder and Collaborative Verification Between Laboratories

建立了婴幼儿配方乳粉中甲醛的检测方法并对其方法进行实验室内和实验室间验证。该方法以2,4-二硝基苯肼(DNPH)作为衍生剂,在室温下进行衍生,采用同位素稀释LC-MS/MS法测定了乳粉中甲醛的含量。经过统计分析,用散点图和箱线图直观地展示了实验室间测定数据的差异。甲醛浓度为0~6 mg/kg时,该方法在5个协同实验室中得到的线性相关系数均大于0.999,线性良好;最低检出限均≤0.6 mg/kg;添加回收率在95.4%~109.3%;相对标准偏差为0.41%~6.45%(n=6),实验室间无显著性差异。结果表明该方法适用于婴幼儿配方乳粉中甲醛的检测。

A method for determination of formaldehyde in infant formula milk powder was established and confirmed by 5 laboratories.Formaldehyde (FA) was analyzed in milk powder by isotope dilution LC-MS/MS using 2,4-dinitrophenylhydrazine (DNPH) as the derivatization agent at room temperature.After statistical analysis of the test results,scatter diagram and box-whisker plots were used to show the difference between laboratories.Good linearity for formaldehyde was obtained with a correlation coefficient (r) of 0.999 in the range of (0~6) mg/kg;the limit of detection (LOD) was 0.6 mg/kg;the relative recoveries ranging from 95.4% to 109.3%;and the relative standard deviation (RSDs) was 0.41%~6.45% (n=6),there was no significant difference between laboratories.This method is efficient for the determination of formaldehyde in infant formula milk powder for its good linearity and high accuracy.