Determination of copper with neocuproine by thermal-lens spectrometry

Conditions for the spectrophotometric determination of copper with 2,9-dime thyl-1,10-phenanthroline (neocuproine) in the presence of ascorbic acid in a water-ethanol solution (9 : 1) at pH 4.5-5.0 have been found. The detecti on limit is 3 x 10(-6) M. The concentration range is from 4.4 x 10(-6) to 3 x 10(-4) M. Conditions for the determination of copper(I) with neocuproine by thermal lens spectrometry have been proposed. The detection limit is 4 x 10(-7) M. The concentration range is from 7 x 10(-7) to 6 x 10(-5) M. Iro n(II) at concentrations as high as n x 10(-4) M does not interfere with the determination of copper. Changes in the conditions for the photometric rea ction associated with passing from spectrophotometric measurements to therm al lensing are discussed.