Determination of phenols at low levels in water samples using automatic flow injection analysis coupled with on-line solid-phase extraction

An automatic flow injection method was proposed using the on-line solid-phase extraction of trace phenols and color development with 4-aminoantipyrine. Phenols at low levels in water samples were pre-concentrated onto OASIS HLB for 20 min at 2 ml min(-1). After elution, color development occurred in the merging zone with 4-aminoantipyrine buffered at pH 10 and hexacyanoferrate(III). The absorbance was measured at 505 mn. The calibration graph for phenol was linear over the range of 0.25 similar to 10 ng ml(-1) with RSD < 1%. The proposed method could be applicable to the analysis of phenols in tap and river water.