Sensitivity enhancement of chlorinated phenols by continuous flow liquid membrane extraction followed by capillary electrophoresis

This paper describes a new analytical system, based on the combination of continuous flow liquid membrane extraction (CFLME) enrichment and capillary electrophoresis (CE) separation, for analysis of chlorinated phenols in water samples. Five chlorinated phenols including 3-chlorophenol (3CP), 4-chlorophenol (4CP) 2,4-dichlorophenol (DCP), 2,4,6-trichlorophenol (TCP), and pentachlorophenol (PCP) were separated by CE with Tris/sodium dihydrogen phosphate solution containing methanol 1% (v/v) as the run buffer. CFLME related parameters were investigated and optimal enrichment was obtained by using 0.3 mol L-1 Tris as acceptor and with a sample pH 5.0, a sample flow rate of 4.0 mL min(-1), and an enrichment sample volume of 150 mL. The detection limit (S/N = 3) was 6.9, 1.0, and 1.7 ng mL(-1) for DCP, PCP, and TCP, respectively. The reproducibility (RSD%, n = 6) was 5.7 for DCP, 2.5 for PCP, and 2.8% for TCP (n = 6). The proposed method was applied to the determination of chlorinated phenols in spiked water samples with relatively satisfactory recoveries.