Differential serum protein binding of benzidine- and benzidine-congener based dyes and their derivatives.

Environmental dyes and their derivatives, some of which are genotoxic, must be transported within the body to the tissues which they affect. One mechanism for this can be observed directly by crossed immunoelectrophoresis (X-IEP). Binding of these chemicals to certain serum proteins changes electrophoretic and immunoprecipitation morphology in X-IEP patterns. This is demonstrated here for four azo dyes derived from benzidine, 3,3'-dimethylbenzidine, and 3,3'-dimethoxybenzidine, and their parent aromatic amines. Direct Red 2 (a 3,3'-dimethylbenzidine-based dye), Direct Blue 15 (a 3,3'-dimethoxybenzidine-based dye), Direct Black 38 (a benzidine-based dye), and Evans Blue (a 3,3'-dimethylbenzidine-based dye) all bound to albumin, alpha 1-lipoprotein, beta-lipoprotein, and hemopexin. Direct Red 2 only slightly affected the mobilities of these proteins. Direct Blue 15 bound also to prealbumin and alpha 1-antichymotrypsin, and degraded C3 globulin. Direct Black 38 and Evans Blue bound to numerous additional proteins. Evans Blue bound variably to proteins of sera from different individuals, suggesting that there are individual differences in serum protein binding capabilities for these chemicals. Of the three derivatives of the benzidine dyes, only 3,3'-dimethylbenzidine caused changes in X-IEP patterns, indicating its binding to the serum proteins. This chemical differentially affected sub-populations of alpha 1-lipoprotein, either by altering its electrophoretic mobility or inhibiting its recognition by antibodies. Autoradiographic analyses demonstrated the binding of benzidine and 3,3'-dimethylbenzidine to both alpha 1- and beta-lipoproteins.

Benzidine and congeners: analytical chemical properties and trace analysis in five substances.

Spectrophotofluorimetric (SPF) methods are described for the trace analysis of benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, and their dihydrochloride salts in microbiological growth media, waste water, potable water, human urine, and rat blood. The salient elements of the methods for these known or suspected carcinogens are: extraction of the residues as the free amine with benzene, rapid cleanup on an alumina column, and quantification of the free amine in methanol via SPF. Potable water solutions of the salts are diluted with buffer (pH-4) and quantified directly by SPF. Ancillary analytical information concerning the solubility and stability of these compounds in water, p-values, gas chromatographic analysis of the free amines, and thin layer chromatographic data in ten solvent systems are also presented.

[Detection of antigens containing benzidine groups in the blood of persons having contact with aniline dyes]. / Opredelenie antigenov, soderzhashchikh gruppirovku benzidina, v krovi u lits, imeiushchikh kintakt s anilinovymi krasiteliami

The paper is concerned with the study of a possibility to record 2-naphtylamine and benzidine in serum and formed blood elements of workers being in contact with dyes, which molecule contain radicals of carcinogens. The Ouchterlony method of precipitation in gel in micromodification and the method of a delay in the precipitation reaction have indicated the presence of benzidine as a haptene in blood serum of 25 among 103 workers and in blood clot extracts in 42 among 116 workers from a textile factory under examination. But 2-naphtylamine was not found in the same subjects.