Determination of copper in biological tissue by means of photochemically generated (Z)-2-thiophenaldehyde 2-pyridylhydrazone

Abstract

An improved and sensitive photometric determination of copper, based on the formation of a coloured chelate with photochemically generated (Z)-2-thiophenaldehyde 2-pyridylhydrazone [(Z)-TAPH], is described. The calibration graph is linear over the range 0.017–1.2 µg ml^–1 of Cu and the method has a detection limit of 5 ng ml^–1 and a relative standard deviation of 0.70%. Colour development is instantaneous and remains stable for at least 4 h; the stoicheiometry of the chelate is 3 : 1 (L : M). The influence of reaction variables and the effect of foreign ions are also discussed. The method is sensitive for the determination of copper(II) and has been satisfactorily applied to the determination of copper in pig liver tissue.