Abstract
The first method (method A) is based on the reaction of ETM with ferric chloride in DMF medium to form a colored species with a λmax at 655 nm. The second method (method B) is based on the oxidative coupling reaction involving ETM, 3-methyl-2-benzothiazolinone hydrazone (MBTH) and ferric chloride in the presence of sodium acetate which yielded a bright pink colored chromogen with λmax.at 520 nm.
