Multivariate calibration applied to simultaneous chemiluminescence determination of cobalt and chromium

Abstract

The simultaneous determination of chromium and cobalt in water samples has been studied. Chemiluminescence registers based on the luminol-hydrogen peroxide reaction have obtained by a batch procedure. PLS algorithms have employed to model the time-response (formation and destruction of emitter). The influence of the presence of two metals and the non-linearity relationship between response and concentration have been evaluated in the signal. Different experimental designs and the selection of variables have been tested. The calibration set has been selected based on two criteria: unicomponent and/or bicomponent standard solutions and the slope calculated from linear univariate calibration. The response has been modelled providing high percentages of explained variance, robust models and low prediction errors. The proposed methodology has been validated using test standard solutions and a standard reference material of fresh water. Accurate results have proved the advantages of this method for the simultaneous determination of chromium and cobalt in water samples.

Determination of Trace Cobalt in Water by Microwave Digestion-Catalytic Fading Spectrophotometry

“…The focus of the determination of trace cobalt is to improve the sensitivity of method and reduce analysis cost. Methods used to determinate cobalt were adsorptive stripping voltammetry [1], solid phase spectrophotometry [2], ultrasonic slurry sampling graphite furnace atomic absorption spectrophotometry [3], chemiluminescence method [4], catalytic kinetic spectrophotometry by artificial neural network [5], fluorescence method [6], membrane filtration-atomic absorption spectrometry [7] and and so on. Some of these methods have complex operation process and the others requires using expensive analysis apparatus.…”