Automatic on-line coupling of supercritical fluid extraction and capillary electrophoresis.
An interface for the automatic coupling of a supercritical fluid extractor (SFE) with capillary electrophoretic (CE) equipment, both commercially available, was developed with a view to improving sample treatment, which is a crucial step in capillary electrophoresis. Extracted analytes were collected in a trap following depressurization in the SFE and were transferred to the CE equipment across the interface. The key elements of the experimental assembly are a laboratory-made programmable arm and the autosampler of the CE equipment, both of which are controlled by a built-in microprocessor using an appropriate electronic interface and customized software. This combined system was successfully used to determine cresols and chlorophenols in liquid samples (river water and human urine) with increased precision, throughput, and automatability. The proposed arrangement opens up interesting prospects for the direct determination of analyte traces in solid samples without human intervention.
Mardones
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Analytical Chemistry Division, University of Córdoba, Campus Rabanales, Spain.
Ríos
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Valcárcel
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