MULTICOMPONENT ANALYSIS BY FLOW-INJECTION USING A PARTIAL LEAST-SQUARES CALIBRATION METHOD - SIMULTANEOUS SPECTROPHOTOMETRIC DETERMINATION OF IRON, COBALT AND NICKEL AT SUB-PMM LEVELS

A partial least-squares multivariate calibration method for:the analys is of binary and ternary mixtures of Fe, Co and Ni, based on their rea ction with 2,2'-dipyridyl ketone picolinoylhydrazone in a flow injecti on manifold was developed. The parameters controlling the behaviour of the system were investigated. For individual determinations, molar ab sorptivities of 6.64 x 10(3) (Fe, 367 nm, 3.89 x 10(3) (Co, 410 nm) an d 5.17 x 10(3) I mol(-1) cm(-1) (Ni, 385 nm), mere obtained, the limit s of detection:being 1.062, 1.489 and 0.685 mu mol l(-1), for Pe, Co a nd Ni, respectively, The optimized method was applied to the analysis of two samples with complex matrices (a washing solution used in an au tomotive factory and a waste acidic mine effluent).