液相色谱-串联质谱法测定食品包装PE材料中荧光增白剂残留量

Determination of fluorescent whitening agent residues in PE materials for food packaging by liquid chromatography tandem mass spectrometry

目的建立同时测定食品包装PE材料中荧光增白剂WS、PF、OB、EBF、EGM、KCB、KSN、OB-1等8种荧光增白剂含量的检测方法。方法采用液相色谱-串联质谱法建立食品包装PE材料中8种荧光增白剂同时测定方法。食品包装PE材料中的荧光增白剂经四氢呋喃和N,N-二甲基甲酰胺提取后,采用Discovery C18柱(150 mm×4.6 mm,5μm)色谱柱,以乙腈和5 mmol/L乙酸铵-甲酸溶液作为流动相,梯度洗脱,液相色谱-串联质谱法(liquid chromatography-tandem mass spectrometry,LC-MS/MS)电喷雾电离源,正离子多反应监测模式测定,外标法定量。结果本文建立的食品包装PE材料中8种荧光增白剂检测低限均可达到0.01 mg/kg;在0.01~6.25 mg/L浓度范围内相关系数均大于0.995,线性关系良好;在0.05、0.25、1.25 mg/kg 3个浓度水平加标回收,回收率在70.8%~99.6%之间;相对标准偏差在1.56%~9.66%之间。结论该方法净化效果好、灵敏度高,且快速简便,可应用于食品包装PE材料中荧光增白剂残留量的检测分析。

Objective To establish a method for the simultaneous determination of fluorescent whitening agent WS,PF,OB,EBF,EGM,KCB,KSN,OB-1 in PE materials for food packaging.Methods The simultaneous determination of 8 fluorescent brighteners in PE materials for food packaging was established by liquid chromatography tandem mass spectrometry.The fluorescent whitening agents in food packaging plastic materials were extracted by tetrahydrofuran and N,N-two methylformamide,then was separated on a discovery C18(150 mm×4.6 mm,5μm)column with acetonitrile and 5 mmol/L ammonium acetate formic acid as mobile phase for gradient elution,detected by liquid chromatography-tandem mass spectrometry(LC-MS/MS)electrospray ionization source,positive ion multiple reaction monitoring mode,and quantified by external method.Results The detection limits of 8 fluorescent whitening agents in food packaging PE materials established in this paper were all 0.01 mg/kg.The correlation coefficient was greater than 0.995 in the concentration range of 0.01–6.25 mg/L,and the linear relationship was good.The recovery rate was 70.8%–99.6%in the concentration levels of 0.05,0.25 and 1.25 mg/kg,and the relative standard deviation was 1.56%–9.66%.Conclusion The method has the advantages of good purification effect,high sensitivity,fast and simple,and can be applied to the determination of fluorescent whitening agent residues in PE materials for food packaging.