应用液相色谱―串联质谱仪和四极杆―轨道阱高分辨质谱仪检测饲料中克伦普罗干扰的原因分析与确证技术研究

Reason analysis and confirmation technology of clenbuterol interference in feed detected by liquid chromatography-tandem mass spectrometer and quadrupole-orbital well high resolution mass spectrometer

目的探究液相色谱―串联质谱仪(liquid chromatography-tandem mass spectrometer,LC-MS/MS)检测饲料中克伦普罗时,环天冬氨酰苯丙氨酸对试验干扰的原因,在此基础上探究出应用LC-MS/MS分析的确证技术与方法。方法应用四极杆―轨道阱高分辨质谱仪和LC-MS/MS对环天冬氨酰苯丙氨酸、克伦普罗对照品以及含有环天冬氨酰苯丙氨酸的饲料样品进行分析。结果饲料中含有环天冬氨酰苯丙氨酸对克伦普罗的检测干扰的原因为二者母离子及2个子离子的质荷比很接近,且二者离子丰度比也很接近。应用LC-MS/MS分析的确证技术与方法为梯度碎裂离子片段依次匹配比较法。结论应用LC-MS/MS检测会遇到假阳性的问题,这是串联质谱结构与方法原理决定的;建议调整克伦普罗的2个子离子为263.07>168.04,263.07>132.06;用LC-MS的梯度碎裂离子片段依次匹配比较法准确、实用。

Objective To study the cause of interference of cycloaspartyl phenylalanine in the detection of clenbuterol in feedstuffs by liquid chromatography-tandem mass spectrometry(LC-MS/MS),and on this basis to study the confirmation technology and method of LC-MS/MS analysis. Methods Quadrupole-orbital trap high resolution mass spectrometer and LC-MS/MS were used to analyze cycloaspartyl phenylalanine,clenbuterol reference substance and feed samples containing cycloaspartyl phenylalanine. Results The reason for the interference of cycloaspartic phenylalanine in the feed to the detection of clenbuterol was that the plasma-charge ratio of the parent ion and the two daughter ions were very close,and the ion abundance ratio of the two was also very close. The confirmation technique and method of LC-MS/MS analysis are gradient fragmentation ion fragment matching comparison method. Conclusion The application of LC-MS/MS will encounter the problem of false positives,which is determined by the structure and principle of tandem mass spectrometry. It is suggested to adjust the two sub-ions of clenbuterol to 263.07>168.04 and 263.07>132.06. It is accurate and practical to use LC-MS gradient fragmentation ion fragments to match comparison method in sequence.