THE APPLICATION OF IMMUNOAFFINITY CHROMATOGRAPHY FOR THE ANALYSIS OF TETRACHLORODIBENZO-P-DIOXIN IN BOVINE MILK

An immunoaffinity column generated by cross-linking a polyclonal chicken antibody with CNBr-activated Sepharose 4B was used for isolation of 1,3,7,8-tetrachlorodibenzo-p-dioxin (1,3,7,8-TCDD) from bovine milk. Direct application of a milk sample, even if diluted 1:50 with 0.05% Triton X-100, interfered with the binding of 1,3,7,8-TCDD to the column. Pre-immunoaffinity column clean-up using liquid-liquid extraction followed by solid phase extraction produced excellent retention of 1,3,7,8-TCDD by the column. The TCDD was easily eluted by increasing the Triton X-100 concentration to 0.5%. Although analysis of milk samples requires more stringent clean up than serum samples, the immunoaffinity chromatography column procedures provide specific clean-up for these samples.