Automated flow analysis system based on multicommutation for Cd, Ni and Pb on-line pre-concentration in a cationic exchange resin with determination by inductively coupled plasma atomic emission spectrometry

A flow system for on-line pre-concentration of Cd, Ni and Pb and determination by inductively coupled plasma atomic emission spectrometry is presented. The manifold comprised a set of three-way solenoid valves, which were controlled by a microcomputer running software written in Quick Basic 4.5 by means of an A/D board. Since the flow network was based on the multicommutation concept pre-concentration and elution steps could be simultaneously performed in several columns in parallel with significant analytical throughput improvement. Comparing obtained results with certified values, no significant difference at 95% confidence level was observed. Other valuable features such as an analytical throughput of 90 determinations per hour, relative standard deviation <4% (n = 10), sample consumption of 7.8 ml per determination were also achieved. (C) 2002 Elsevier Science B.V. All rights reserved.