气相色谱-质谱法测定猪可食性组织中3种β-兴奋剂残留的基质效应

Matrix effects in analysis of three β-agonist residues in pig edible tissues using gas chromatography-mass spectrometry

建立了气相色谱-质谱法测定猪可食性组织中克伦特罗、沙丁胺醇及莱克多巴胺3种β-兴奋剂残留的分析方法,评价了基质的状态和重量等因素对基质效应的影响.用N,O-双三甲基硅基三氟乙酰胺衍生,气相色谱-质谱选择离子监测模式测定猪肝和肌肉组织及其相应冻干粉中3种药物残留及其基质效应强度,均显示显著的基质增强效应,特别是莱克多巴胺的基质效应超过1000％.方差分析表明,不同基质重量的基质效应差异显著（P＜0.05）,样品重量在1～5g范围内,3种药物的基质效应随样品重量增加而增大;猪肝和猪肉鲜样与其相应冻干粉的基质效应差异均不显著（P＞0.05）.选择猪组织的冻于粉配制基质匹配标准溶液,能够有效、方便地校正气相色谱-质谱测定β-兴奋剂残留的基质效应.

A gas chromatography-mass spectrometry （GC-MS） method was established for the determination of the residues of three β-agonists （ clenbuterol, salbutamol and ractopamine） in pig edible tissues. The matrix effects （MEs） in the analysis of the three compounds with the developed method were determined. The influences of matrix state and its weight on MEs were evaluated statistically. The analytes in pig liver and muscle and their corresponding freeze-dried powders were derivatized with N, O-bis （trimethylsilyl） trifluoroacetamide. Then the derivatives were determined in selected ion monitoring mode and the intensities of MEs of the three β- agonists were obtained. Significant matrix enhancement was observed for the three analytes, and especially, the ME of ractopamine was more than 1000%. The results of analysis of variance （ANOVA） demonstrated that MEs were significantly different for the three analytes in two matrices among different matrix weights （P 〈 0.05）, and MEs of the three analytes increased from I g to 5 g with the increase of matrix weight. MEs for the three analytes were not signifi- cantly different between fresh pig tissues and its freeze-dried powder matrices （P 〉 0.05）, indicating that the freeze-dried powder matrices might be used to conveniently prepare the matrix-matched calibration solution, which could efficiently compensate the MEs of the β- agonists in GC-MS analysis.