On-line methodology for the trace level determination of the chlorinated phenol family in water samples

Abstract

On-line solid-phase extraction – liquid chromatography (SPE-HPLC) methodology was developed for the trace level determination of phenol and 19 chlorophenols in water samples. A small precolumn packed with polymeric adsorbent was placed in a switching valve and used for sample extraction and preconcentration; the trapped compounds were further on-line eluted and analyzed by reversed phase HPLC with UV and coulometric detection. Because of wide differences in hydrophobic character, SPE of the least (phenol and monochlophenols), the medium (di- and trichlorophenols) and the most chlorinated phenols (tetra- and pentachlorophenol) was performed using different sample volume (15-25 mL) and sample composition (0-10% methanol addition). Under these conditions, solute recoveries were ≥ 82% (except phenol, 72%) for concentrations in the range ~3-75 ng/mL. Applying recovery factors, excellent accuracy (100%) and precision (RSD < 6.5%) were achieved for the 20 compounds of interest in replicate analysis (n = 7) of spiked reagent water samples. Method detection limits were 0.5-1 ng/mL with the UV detector and 0.1-0.3 ng/mL with the coulometric detector.