Analysis of nonylphenol polyethoxylates and their degradation products in river water and sewage effluent by gas chromatography-ion trap (tandem) mass spectrometry with electron impact and chemical ionization

A method is presented for the analysis of nonylphenol polyethoxylate (NPEO) residues and their degradation products, nonylphenol polyethoxy carboxylates and carboxyalkylphenol ethoxy carboxylates, in the samples of river water and sewage effluent. The method involves extraction of the samples by graphitized carbon black (GCB) cartridge, propylation by a propanol/acetyl chloride derivatization procedure, and separation, identification and quantitation by ion-trap GC-MS with electron impact ionization (EI), liquid-chemical ionization (CI) and CI-MS-MS modes. The large-volume injection technique provides high precision and sensitivity for both NPEO residues and their degradation products, to quantitation at ≥0.01 μg/l in 100 ml of water samples. Dicarboxylic acids of NPEO residues were identified by the CI-MS-MS technique with relatively high concentrations in the samples of river water and sewage effluent. Recovery of nonylphenol and octylphenoxyacetic acid in spiked water samples ranged from 81 to 107%. Relative standard deviations of replicate analyses ranged from 2 to 12%. Copyright (C) 1998 Elsevier Science B.V.