Catalytic test determination of copper on a solid support

A test procedure was developed for the determination of 5 × 10−7−1 × 10−3 M copper with the use of the copper-catalyzed reaction of the reduction of molybdophosphoric acid by thiourea on a solid support (paper). The conditions of the indicator reaction and the technique for its conduction were optimized; the pH range in which the acidity of the solution does not affect the time of the reaction was revealed. The calibration plot for the determination of copper was constructed in reaction time-pCu coordinates. The effect of different components on the rate of the indicator reaction was studied. The procedure was approved in the analysis of real and model solutions.