Extraction and spectrophotometric determination of mercury with N-p-chlorophenylbenzohydroxamic acid (N-p-Cl-BHA)

Extraction and spectrophotometric studies of tracer amounts of mercury with N-p-chlorophenylbenzohydroxamic acid are described. The yellow color mercury complex was extracted from chloroform at pH 9.0. The spectral measurement was made at 388 nm and the molar absorptivity of the complex is 6.0 × 10² liters mol^?1 cm^?1. It gives a clean separation from many commonly occurring metal ions. Effects of pH, solvents, electrolytes, and reagent concentration on the extraction of mercury have been discussed. The mercury is determined in drug samples and industrial effluents. From the extraction data an attempt has been made to calculate the stability constant of mercury complex.