液相色谱-串联质谱法测定婴幼儿配方乳粉中六种消毒剂残留

建立了婴幼儿配方乳粉中苯扎溴铵、C12-苯扎氯铵、C14-苯扎氯铵、C16-苯扎氯铵、二癸基二甲基氯化铵和四丁基硫酸氢铵等6种消毒剂的液相色谱-串联质谱测定方法。样品经水超声提取,乙腈除蛋白,液相色谱-串联质谱仪测定,基质外标法定量。结果表明,6种消毒剂的线性范围为0.5～20μg/L,相关系数(r2)均大于0. 99。方法的检出限(LODs,信噪比为3)在0.2μg/kg,定量限(LO?Qs,信噪比为10)在0.5μg/kg。基质中3个加标水平的回收率都在87.3%～104.6%之间,加标含量范围为0.5～5.0μg/kg,相对标准偏差(RSD,n=6)在2.96%～9.87%之间。采用建立的方法对市面上销售的50种婴幼儿配方乳粉中6种消毒剂进行了筛查,达到了预期效果。方法能满足婴幼儿配方乳粉消毒剂残留的检测工作的要求。

Determination of six disinfectants in infant milk powder by high performance liquid chromatography-tandem mass spectrometry

A rapid method for the determination of benzalkonium bromide, C12-benzalkonium chloride, C14-benzalkoniumchloride, C16-benzalkonium chloride, didecyl dimethyl ammonium chloride, tetrabutyl ammonium hydrogen sulfate in infant milk powder was established using high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS).The samples were ultrasonic extracted with water, Acetonitrile remove protein.The separation of the analytes was carried out on an Hypersil GOLD C18(4.6×50 mm, 1.9 μm) using the mobile phases of 0.2% Formic acid 20 mmol/L Ammonium acetate aqueous solution and methanol with elution. The detection of six disinfectants were carried out in the positive multi-reaction monitoring(MRM)mode. The linearities were excellent in the range of 0.5-20 μg/L with the correlation coefficients above 0.99.The limits of detection( LODs,S/N = 3) of the method was 0.2 μg/kg,and the limits of quantification( LOQs,S/N =10) was 0.5 μg/kg. The recoveries of disinfectants spiked were between87.3% and 104.6% at the spiked levels ranged from 0.5 μg/kg to 5.0 μg/kg.The relative standard deviations( RSDs,n= 6) were in the ranges of 2.96%~9.87%.The developed method was successfully applied for disinfectants analysis in more than 50 samples.The method can meet the requirements of the daily work for the determination of disinfectants in infant milk powder.