Simultaneous spectrophotometric determination of lead, copper and nickel using xylenol orange by partial least squares

Abstract

A partial least squares (PLS) calibration model was developed for the simultaneous spectrophotometric<br />determination of Pb (ΙΙ), Cu (ΙΙ) and Ni (ΙΙ) using xylenol orange as a chromogenic reagent. The parameters<br />controlling behavior of the system were investigated and optimum conditions were selected. The calibration<br />graphs were linear in the ranges of 0.0–9.091, 0.0–2.719 and 0.0–2.381 ppm for lead, copper and nickel,<br />respectively. The experimental calibration matrix was designed with 21 mixtures of these chemicals.<br />Absorbance data were taken between 350-650 nm and absorbance data were autoscaled. A set of synthetic<br />sample mixtures were used to validate the proposed method. The root mean square errors of predictions<br />(RMSEPs) and percent of relative prediction errors (RSEPs) are 0.2164, 0.0744, 0.0735 ppm and ±7.1855, ±<br />6.3193, ± 7.0806% for lead, copper and nickel, respectively.