Equilibrium Sampling through Membranes of Freely Dissolved Copper Concentrations with Selective Hollow Fiber Membranes and the Spectrophotometric Detection of a Metal Stripping Agent
- 26 October 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in Analytical Chemistry
- Vol. 77 (23), 7605-7611
- https://doi.org/10.1021/ac050763a
Abstract
A sensitive spectrophotometric method for the determination of freely dissolved copper concentrations in aqueous samples after preconcentration with hollow fiber membrane extraction has been developed. The method is based on the equilibrium sampling through a selective membrane into an acceptor solution containing 4-(pyridyl-2-azo)resorcinol (PAR), which serves as stripping agent and metal indicator. Negligible extraction of interferences and equilibrium enrichment of copper allowed for selective spectrophotometric determination of the Cu−PAR complex. Some important extraction parameters such as acceptor composition, shaking, equilibrium time, and sample volume were studied. The optimized methodology showed good linearity in the range of 5−100 μg/L, an enrichment factor of 93, good repeatability and reproducibility (RSDs < 6%, n = 6), and a detection limit of 4 μg/L. The cationic metals Ni2+, Co2+, Cd2+, Fe3+, Pb2+, Zn2+, and Mn2+ were shown not to interfere with the measurement of Cu2+. Measurements on samples containing mixtures of various ligands and cations were in good agreement with theoretically calculated concentrations, and the method was also applied to environmental samples. The developed technique requires less labor and less sophisticated equipment than conventional methods typically based on atomic absorption spectrometry or ICP.Keywords
This publication has 22 references indexed in Scilit:
- Permeation liquid membrane as a tool for monitoring bioavailable Pb in natural watersScience of The Total Environment, 2004
- Developments in hollow fibre-based, liquid-phase microextractionTrAC Trends in Analytical Chemistry, 2004
- Copper(II)-selective membrane electrode based on hydrotris(3-isopropylpyrazolyl)methane in a poly(vinyl chloride) matrixAnalytica Chimica Acta, 2003
- Peer Reviewed: Equilibrium Sampling DevicesEnvironmental Science & Technology, 2003
- Determination of copper in seawater based on a liquid membrane preconcentration systemAnalytica Chimica Acta, 2002
- Sensing Dissolved Sediment Porewater Concentrations of Persistent and Bioaccumulative Pollutants Using Disposable Solid-Phase Microextraction FibersEnvironmental Science & Technology, 2000
- Technology Solutions: An array of possibilities for evaluating environmental healthEnvironmental Science & Technology, 2000
- Hollow fiber based supported liquid membrane: a novel analytical system for trace metal analysisAnalytica Chimica Acta, 1997
- Detection of bias in method comparison by regression analysisAnalytica Chimica Acta, 1997
- Statistical Estimation of Linear Calibration RangeAnalytical Letters, 1996