title: Manual and fia methods for the determination of cadmium with malachite green and iodide.
abstract: A sensitive and rapid spectrophotometric method for the determination of cadmium is described, based on the formation of a blue complex at pH 4 between the anionic iodide complex of cadmium(II) and Malachite Green; the colour is stabilized with poly(vinyl alcohol). The calibration graph for measurement at 685 nm is linear over the range 1-50 mug of cadmium per 25 ml of final solution, with a relative standard deviation of +/-1.7% for 1 mug/ml cadmium. The molar absorptivity is 6.1 x 10(4) 1.mole(-1).cm(-1). The method can be successfully adapted for FIA, the peak height being proportional to the cadmium concentration over the range 0.1-3 mug/ml; a two-channel manifold is used and an improvement in selectivity is obtained. The use of a gradient tube is demonstrated to give a good calibration for Cd(II) over the range 2 x 10(-2) -2 x 10(-6)M.
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Murcia, 30001 Murcia, Spain.
authors.forename: I L
authors.initials: IL
authors.lastname: Garcia
authors.forename: P
authors.initials: P
authors.lastname: Navarro
authors.forename: M H
authors.initials: MH
authors.lastname: Cordoba