Spectrophotometric determination of phenols in water samples by the GHPSAMmethod

The generalized H-point standard-additions method (GHPSAM) is proposed in o rder to obtain the phenol concentration in water samples when the matrix is completely unknown. The procedure involves solid-phase extraction in BondE lut PPL cartridges and data handling of the UV-visible spectrophotometry me asurements. The spectral regions where the unknown interferent behaviour ca n be considered as linear are found and the analyte concentration free from bias error is estimated. The percentages of recovery of phenols in spiked samples were similar to those obtained by HPLC. Cresols or chlorophenols ca n be also determined in real samples by this method. The concentration rang e tested was 0.075 - 12.5 mg L-1 and the limits of detection found were in the 2.4 - 5.4 mug L-1 range. The method has been applied to real harbour wa ter samples. The results obtained are compared to those provided by HPLC.