Simultaneous determination of copper and iron by flow-injection catalytic kinetic spectrophotometry with multi-channel detector

The simultaneous determination of copper and iron by catalytic kinetic spectrophotometric method with back propagating artifical neural net (BP-ANN) was studied based on the catalysis of Cu(II) and Fe(III) to the reaction of rhodamine B hydrogen peroxide in the range of pH 3-9. The determination was performed by the construction of pH gradient and a CCD-diode array detector with a microcomputer. The optimum conditions of reaction and flow injection were studied. The determination limits for copper and iron were 0.10 and 0.21 mug.L-1, respectively. The sampling rate was 10 samples per hour. The proposed method has been used to determine Cu(II) and Fe(III) in certified reference materials and food samples with satisfactory results. The average values of spiked recovery were 93.3 % -100.2 % with RSD of 0.6 % -7.5 %.