Title: A method for preparing analytically pure sodium dithionite. Dithionite quality and observed nitrogenase-specific activities
Abstract: Sodium dithionite (Na2S2O4) is widely used as a reductant in biochemical studies, but has not been available in its pure form. A convenient, detailed procedure is given for the recrystallization of commercial dithionite from 0.1 M NaOH-methanol under anaerobic conditions. Twice-recrystallized dithionite had a purity of 99 ± 1% by UV spectroscopy (A315) and elemental analysis. The influence of dithionite quality on the apparent reduction activities of the nitrogenase components (Av1 and Av2) from Azotobacter vinelandii was investigated.