Zenovia Moldovan
University of Bucharest, Faculty of Chemistry, Department of Analytical Chemistry,
4-12 Regina Elisabeta Blvd, 703461 - Bucharest, Romania
 

Laurenţia Alexandrescu
Research Development National Institute for Textile and Leather - Division Leather and Footwear Research Institute, 93 Ion Minulescu St., Sect 3, 74259 - Bucharest, Romania
 
 

Abstract
A method for the determination of 2-mercaptobenzimidazole (MB) in mixtures by derivative spectrophotometry has been developed. MB is used as antioxidant in the manufacture of industrial rubber. Derivative spectrophotometry has been applied for the elimination of the mutual interferences of the other polymer additives in the MB estimation. Thus, the procedure works whitout any separation step of MB from the other polymer additives. The second derivative spectrum of MB was measured at  304 nm while the third derivative was measured at 308 nm. At these wavelengths, the spectra of the other additives cross the zero line or are insignificant. The derivative spectrophotometric procedure was applied for MB determination in synthetic mixtures of polymer additives and in rubber samples.