莱克多巴胺ELISA检测假阳性原因分析

The false positive analysis of ractopamine detection by enzyme-linked immunosorbent assay

目的对酶联免疫吸附测定法(enzyme-linked immunosorbent assay,ELISA)检测莱克多巴胺假阳性结果产生的原因、影响因素和质量控制方法进行分析研究。方法应用经验证可靠的ELISA方法对进口猪肉产品进行莱克多巴胺兽药残留初筛检测,对阳性可疑样品采用液相色谱.串联质谱分析方法进行确证检测,并对两种方法的检测结果进行对比分析。结果样品在腐败变质后产生含有可以产生非特异性显色内源性辣根过氧化物酶的细菌,从而造成假阳性,干扰检测结果。结论莱克多巴胺检测中造成酶联免疫吸附(ELISA)方法假阳性结果的主要原因包括莱克多巴胺的代谢速度快,ELISA检测所用抗体与莱克多巴胺的交叉反应性高,以及样品因素的影响。

Objective To research the reasons, influence factors and quality control methods of the false-positive results for ractopamine detection by enzyme-linked immunosorbent assay (ELISA). Methods The ractopamine residues in imported porcine products was detected using ELISA, and positive samples were further determined by HPLC-MS/MS confirmatory method. Furthermore, the results of those two methods were compared and analyzed. Results The bacteria could thrive in the spoilage samples and gendogenous horseradish peroxidase contained in it. It caused nonspecific coloration resulting in false positive results and interference of the detection. Conclusion The reasons which cause the false positive by ELISA to detect ractopamine are the fast metabolic rate of ractopamine, the high cross reactivity of ractopamine antibody by ELISA and the effect of sample factors.