Simultaneous determination of ammonia, aliphatic amines, aromatic amines and phenols at μg l−1 levels in environmental waters by solid-phase extraction of their benzoyl derivatives and gas chromatography-mass spectrometry

Abstract

Low concentrations of phenols and amines in environmental waters and their low breakthrough volume during solid-phase extraction (SPE) hinder the detection of phenols and aromatic amines, whereas ammonia and aliphatic amines are not suitable for SPE. Pre-column derivatization to arylbenzoates and N-alkyl- or N-arylbenzamides and their GC-MS is proposed to separate and determine phenols and amines in aqueous samples in the range 0.1–100 μg l⁻¹ with correlation coefficients in the range 0.9910–0.9992. The limit of detection ranged from 7 to 39 ng l⁻¹ for most analytes (90 ng l⁻¹ for 2,3,6-trichlorophenol and 20 μg l⁻¹ for ammonia) when 80 ml of sample were preconcentrated, after derivatization, on a styrene–divinylbenzene copolymer sorbent. The developed method was applied to spiked drinking water, groundwater and river water samples, and was used to detect halo-phenols in paper mill effluents. The average recovery ranged from 96 to 110% with RSD of 4–12%. The described method is rapid and can be applied to control the water quality of environmental waters with respect to three important classes of organic pollutants and ammonia.