Enzyme-linked immunoassay of malachite green in aquatic products: elimination source of matrix interference and elimination strategy

Malachite green ( MG) is now considered one of the most important hazards in aquatic products. The efficiency of enzyme-linked immunosorbent assay (ELISA) for MG in aquatic products was investigated and validated by using Scophthalmus maximus,Pseudosciaena crocea and Penaeus vannamei as samples. The results indicated that, the presence of matrix components could significantly interfere the ELISA,and some proteins were proved to contribute greatly to the matrix interference investigated. A pretreatment of the samples with 9% trichloroacetic acid was demonstrated to be able to remove the proteins effectively,therefore significantly improve the accuracy of the ELISA. At a spiking concentration of 0.5 μg / kg,the average recovery for the three kind of aquatic products was demonstrated in the range of 120%-130 % ,with all relative standard deviations below 11.2% ,which indicated the application prospect of the technique for fast screening of the MG residue in aquatic products.