Trace enrichment of phenols by on-line solid-phase extraction and gas chromatographic determination

An on-line gas chromatographic pretreatment module for the preconcentration/determination of phenols in waters is proposed. A solid-phase extraction system using different sorbents packed in a minicolumn is coupled on-line with a gas chromatograph equipped with flame ionization detection (FID). The XAD-2 sorbent selected provides detection limits from 0.3 to 2 mu g/l for 100 ml of water at an acid pH. The relative standard deviations for eleven analyses of samples containing 10 mu g/l phenols were 2.3-4.5%. The proposed method can be used for the routine analysis of natural and drinking waters containing phenols at trace levels.