Evaluation of multicomponent flow-injection analysis data by use of a partial least squares calibration method

This paper reports on the use of a flow-injection analysis technique for the simultaneous spectrophotometric resolution of binary and ternary mixtures with the aid of a multivariate calibration method, and its application to the simultaneous determination of Co(II), Cu(II) and Zn(II) with 2-carboxyl-2-hydroxy-5-sulfoformazylbenzene (Zincon) over the concentration range 0.397–1.590, 0.268–1.879 and 0.240–1.612 μg/ml, respectively. Multicomponent analysis was implemented by using a modified version of the partial least squares program. The influence of various chemical and FIA variables affecting the reaction was evaluated. The proposed method was successfully applied to the determination of cobalt, copper and zinc in synthetic mixtures; copper and zinc in blood serum; and cobalt, copper and zinc in veterinary formulations.