Spectrophotometric determination of hydrazine, hydrazides, and their mixtures with trinitrobenzenesulfonic acid

Abstract

A method has been developed to measure hydrazine, hydrazides, and their mixtures using a modification of the trinitrobenzenesulfonic acid method [T. Okuyama and K. Satake (1960) J. Biochem. (Tokyo) 47, 654–660]. After incubation of the sample containing hydrazine and hydrazide with trinitrobenzenesulfonate at pH 8.5 at room temperature for 40 min, the reaction mixture was diluted with a Na 2CO 3-NaHCO 3 buffer (0.1 m, pH 10.8) rather than with 0.5 m HCl. Different chromogens were produced from the reaction of hydrazine (λ max = 570 nm) and hydrazides (λ max = 385 and 500 nm) with trinitrobenzenesulfonic acid. The method allowed simultaneous determination of hydrazine (5 to 60 nmol) with hydrazide (10 to 120 nmol) in a mixture with a standard deviation of less than 5%. The presence of amino compounds (except for amino sugars) did not interfere with the measurement of hydrazine or hydrazides. Interference by amino sugars in the determination of hydrazine or hydrazides was eliminated by pretreatment of the sample with NaBH 4 to reduce the amino sugars to 2-amino-2-deoxyhexitols.