Analytical application of porphyrins-I Spectrophotometric determination of ultramicro amounts of copper with alpha,beta,gamma,delta-tetra-(3-N-methylpyridyl)porphine

A new water-soluble porphyrin, alpha,beta,gamma,delta-tetra(3-N-methylpyridyl)porphine T(3-MPy)P], has been synthesized, and its reaction with copper(II) studied spectrophotometrically. Sensitive methods for the determination of copper at ppM level have been established. The spectrophotometric sensitivity and relative standard deviation of the recommended procedure for copper are 0.18 ng/cm(2) (for A = 0.001) and 1.0%, respectively. The interference of 19 ions and 20 salts has been examined, and found to be minimal. The methods established could be applied to the determination of copper in water samples with satisfactory results.