Selective immuno-supported liquid membrane (ISLM) extraction, enrichment and analysis of 2,4,6-trichlorophenol

2,4,6-Trichlorophenol (2,4,6-TCP) was extracted from liquid samples (standards and spiked river water) using immuno-supported liquid membrane (ISLM) extraction followed by fluorescence flow immunoassay (FFIA) detection of the immuno-extracted analyte. ISLM–FFIA involves simultaneous on-line sample clean-up, enrichment and detection of analytes. The analyte is transported from a continuously flowing aqueous sample phase (donor) through a supported liquid membrane (SLM), containing an immobilised organic solvent, to a stagnant aqueous phase (acceptor), containing excess anti-analyte antibody, where it is trapped as analyte–antibody complex. The acceptor content is then dispensed and mixed on-line with a fluorescent analyte tracer (2,4,6-TCP/NH/(CH2)3/CO/EDF) and the resulting labelled fraction, separated from the mixture by restricted access column, is an indirect measure of the analyte amount extracted in the acceptor. The performance of ISLM–FFIA was compared with a similar FFIA (without the extraction step) with the following results: the ISLM–FFIA configuration leads to improved assay sensitivity (LOD 27.92 ± 2.44 and 224 ± 5.86 μg L−1 for ISLM–FFIA and FFIA, respectively) and improved selectivity and recovery for 2,4,6-TCP in presence of other chlorophenols (e.g. 2,4,5-trichlorophenol and 4-chlorophenol) compared to FFIA alone.