UPLC-MS/MS法测定冰淇淋与雪糕中3种季铵盐类化合物

Determination of Three Quaternary Ammonium Compounds in Ice Creams by Solid Phase Extraction and Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

基于固相萃取（SPE）技术和超高效液相色谱-质谱／质谱仪（UPLC—MS／MS），建立了-种测定冰淇淋和雪糕中3种季铵盐消毒剂（十二烷基二甲基苄基氯化铵、十六烷基二甲基苄基氯化铵和苄索氯铵）残留量的方法。样品融化混匀后，用乙腈提取和沉淀蛋白，提取液经弱阳离子交换（WCX）固相萃取柱净化，氮吹浓缩后，采用亲水色谱柱（HILIC）在0．1％甲酸乙腈-10mmol／L乙酸铵流动相体系中等度分离，在质谱的电喷雾（ESI）离子源正模式和多反应监测（MRM）模式下测定。结果表明，3种季铵盐在0．5—20μg/L范围内线性关系良好，相关系数均大于0．999，方法的定量下限（S／N=10）为3．0—5．5μg／kg，3个加标水平的平均回收率为90．7％～102．2％，相对标准偏差（RSD，n=6）为2．4％～6．4％。该方法简单，准确灵敏，重现性好，适用于冰淇淋和雪糕中3种季铵盐消毒剂的检测。

A new method was developed for the determination of three quaternary ammonium com- pounds（QACs） residues, including dodecyl dimethyl benzyl ammonium chloride （C12 -BAC）, hexadecyl dimethyl benzyl ammonium chloride（ C16 -BAC） and benzethonium chloride in ice creams using solid phase extraction（SPE） and ultra performance liquid chromatography- tandem mass spec- trometry（ UPLC -MS/MS）. The samples were melted and mixed, and then added into acetonitrile to extract target compounds and precipitate protein. The supernatant was purified with weak cationic ex- change solid phase extraction cartridge （WCX） and concentrated in nitrogen stream. The separation of three quaternary ammonium compounds was performed on a Waters BEH HILIC column（50 mm× 2. 1 mm, 1.7 μm） by isocratic elution using acetonitrile（ containing 0. 1% formic acid） -10 mmoL/ L ammonium acetate as mobile phase. The targets were analyzed under the multiple reaction monito- ring（MRM） mode in positive electrospray ionization. The results showed that the calibration curves of three QACs were linear in the range of 0. 5 -20 μg/L with correlation coefficients greater than 0. 999. The method quantitation limits （ LOQs, S/N = 10 ） of three analytes ranged from 3.0 μg/kg to 5.5 μg/kg. The average recoveries were in the range of 90.7% - 102.2% , and the relative standard de- viation（RSD, n =6） were 2. 4% -6. 4% at three spiked levels of standard. With the advantages of sim- plicity, accuracy, sensitivity and good reproducibility, the method could be used for the determination of QACs residues in ice creams.