Extraction-Spectrophotometric Determination of Cu(II) with 6,7-Dihydroxy-4-Methyl-2-Phenylbenzopyrylium Chloride in Waters of Various Categories

The extraction conditions of the Cu(II) complex with 6,7-dihydroxy-4-methyl-2-phenylben-zopyrylium chloride having component ratio 1 : 2 and formed in the solution at pH 4.5 have been optimized. Isoamyl alcohol was shown to be the most effective extractant. It was established that the extraction equilibrium was achieved during one minute, while the optimal ratio of organic and aqueous phases was equal to 1 : 5. The values determined of distribution coefficient (D) and complex recovery ratio ( R ) amounted to 61 and 92%, respectively. A high sensitivity extraction-spectrophotometric technique for determining Cu(II) by using 6,7-dihydroxy-4-methyl-2-phenylbenzopyrylium chloride was developed. This technique is relatively simple and features the detection limit of 0.007 μg/cm 3 . The calibration graph is linear in the range 0.02–0.96 μg/cm 3 . This technique was approbated in the process of analyzing different categories of water.