Determination of proteins by using the color reaction with pyrocatechol violet-molybdenum(VI) complex.

Abstract

A method for the determination of proteins (as albumin) with pyrocatechol violet (PV)-molybdenum (VI) [Mo (VI)] complex in the presence of polyvinyl alcohol was established. This method is based on the formation of the PV-Mo (VI)-protein complexes, which have absorption maxima at around 680 nm in weakly acidic media. The method could be used to determine up to ca. 300 μg/10 ml of albumin at 680 nm, and is superior to the Coomassie brilliant blue method and the pyrogallol red (PR)-Mo (VI) method in terms of sensitivity and reproducibility. Recovery of albumin added to human urine was good.