Abstract: An ultra-high performance liquid chromatography tandem triple quadrupole mass spectrometry (UPLC-MS/MS) method was established for the determination of six quaternary ammonium disinfectant residues in milk-containing food for special medical purposes. The sample was extracted with 80% acetonitrile in water and the extract was separated on a RRHD Eclipse Plus C18 column, detected in the positive ion mode using an electrospray ionization source with multiple reaction monitoring (MRM), and quantified by matrix-matched standard calibration. The calibration curves for the six quaternary ammonium disinfectants was linear in the concentration range of 0.1–5.0 ng/mL with correlation coefficient higher than 0.996 0. The limit of detection (LOD) was 0.5 μg/kg and the limit of quantification (LOQ) was 1 μg/kg. The recoveries were 72.8%-102.3% for spiked solid matrix samples, and 71.8%–100.8% for spiked liquid matrix samples with relative standard deviations (RSDs) in the range of 0.25%–3.88% and 0.19%–2.51%, respectively. The proposed method is simple, efficient, rapid, sensitive, and suitable for the qualitative and quantitative analysis of quaternary ammonium disinfectant residues in food for special medical purposes.

Key words: food for special medical purposes; disinfectants; quaternary ammonium; ultra-high performance liquid chromatography-tandem triple quadrupole mass spectrometry

摘要： 基于超高效液相色谱-串联三重四极杆质谱法建立含乳成分的特殊医学用途配方食品中6 种季铵盐类消毒剂残留的检测分析方法。使用80%乙腈水溶液作为提取溶液对样品进行提取，采用RRHD Eclipse Plus C18色谱柱进行分离，选择电喷雾离子源，在正离子模式下（ESI＋）采用多反应监测模式进行检测，用基质匹配工作曲线进行定量。结果表明：6 种季铵盐类消毒剂在0.1～5.0 ng/mL质量浓度范围内具有良好的线性关系，线性相关系数＞0.996 0，检出限为0.5 μg/kg，定量限为1 μg/kg；固体基质中加标回收率为72.8%～102.3%，相对标准偏差（relative standard deviation，RSD）为0.25%～3.88%；液体基质中加标回收率为71.8%～100.8%，RSD为0.19%～2.51%。方法简单、高效、快捷、灵敏，能够很好地用于特殊医学用途配方食品中季铵盐类消毒剂的分析测定。

关键词: 特殊医学用途配方食品；消毒剂；季铵盐；超高效液相色谱-串联三重四极杆质谱法