A modified and highly sensitive spectrophotometric method for the determination of nitrate in trace quantities in environmental samples is described. The method is based on the reaction of nitrate ion with brucine and 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in sulfuric acid medium to yield a violet-colored product which is stable for over two days. The optimum photometric ra...

A novel spectrophotometric enzymlc procedure for estimating oxalic acid in urine is described. Oxalate oxidase, prepared from moss species, converts oxalic acid to hydrogen peroxide and carbon dioxide. Hydrogen peroxide is determined enzymatically with horseradish peroxidase, by oxidative coupling of 3-methyl-2-benzothiazolinone hydrazone with N,N-dimethylaniline; the resulting indamine dye is ...

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-( - )-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. Th...

Four simple and sensitive methods for the assay of prazosin hydrochloride (PRH) are developed. These methods are based on the formation of coloured species by treating it either with excess N-bromosuccinimide (NBS) and determining the unconsumed NBS with p-N-methyl aminophenol sulphate (metol)-sulphanilamide (SA) reagent (method A, lambda(max) 520 nm): with 3-methyl-2-benzothiazolinone hydrazon...