Rapid analysis of ultra trace amounts of anions in water by solid phase extraction and ion chromatography

Abstract

The use of solid phase extraction (SPE) technique prior to ion chromatography (IC), for relative enrichment of inorganic anions is reported. The SPE is directly coupled with the IC and comparison has been made between the -detection limits of IC, both on its own, and in combination with-SPE. It has been shown that detection limits can be reduced 100 fold using this combined technique. A number of parameters such as eluent strength , <i>p</i>H and flow rate have been studied.. The suppressed and non-suppressed SPE/IC have been examined for the analysis of aqueous samples. The suppressed SPE/IC is found to have lower detection limits than the non-suppressed method. Recovery data and matrix dependencies have been studied at concentration levels ranging from 1 to 10μg/l. Comparing to off line SPE method, on line SPE/IC reduces the analysis time by at least factor of two.