Sequential Determination of Mono- and Divalent Copper in Water by Flow-Injection Analysis

Abstract

A simple and sequential method is presented for the fast speciation of copper in aqueous media. The use of a spectroelectrochemical flow-cell allows the quantification of individual copper oxidation states using a combination of spectroscopical and electrochemical techniques. The proposed method is based on a reverse flow injection system (r-FIA) for the spectrophotometric determination of Cu (II) with cuprizone, with a linear fit between 1.2 and 12 μg mL−1 and a detection limit of 0.11 μg mL−1. Amperometric determination of Cu (I) is synchronized with the optical measurement to avoid interferences and has a linear behavior ranged from 0.04 to 0.8 μg mL−1 and a detection limit of 7.7 ng mL−1.