On-line membrane extraction liquid chromatography for monitoring semi-volatile organics in aqueous matrices

Membrane extraction is an attractive alternative to conventional extraction methods, such as liquid-liquid extraction and solid phase extraction, beca use the analytes can be isolated in a continuous fashion. On-line detection can be carried out using a suitable analytical instrument. The objective o f this study is to study the enrichment of semi-volatile organic compounds (SVOCs) from an aqueous matrix by on-line membrane extraction, to be follow ed by liquid chromatographic (ME-LC) analysis for continuous monitoring. Th e membrane serves as an interface across which liquid-liquid extraction tak es place. The SVOCs transfer from the aqueous phase and are concentrated in an organic extractant. The enriched solvent is intermittently injected int o an HPLC for analysis. In this paper, the enrichment into the organic phas e under different operating conditions and the performance characteristics of the instrumentation are presented. (C) 2000 Elsevier Science B.V. All ri ghts reserved.