Determination of microcontaminants in sediments by on-line solid-phase extraction-gas chromatography-mass spectrometry

Two simple and straightforward analytical procedures for the screening of s ediment samples are reported. They involve extraction with ethyl acetate or methanol and subsequent analysis by means of gas chromatography-mass spect rometry (GC-MS) using large-volume injection (LVI) or solid-phase extractio n (SPE). The latter, which was originally developed for the analysis of aqu eous samples, can be used without any modification. In general, 10 ml of or ganic solvent were added to 2 g of sediment, and the mixture was shaken and allowed to stand overnight. The methanolic extracts were then diluted in w ater and subjected to preconcentration and analysis using on-line SPE-GCMS. The ethyl acetate extracts were injected directly into the GC using LVI. B oth methods were used for the detection and identification of microcontamin ants during a monitoring study of the river Nitra (Slovak Republic). They i ncluded polyaromatic hydrocarbons (PAHs), chlorofluorohydrocarbons, alkoxyl ated and alkylated phenols and benzothiazole derivatives. Semi-quantitative profiles of the contaminants were constructed and provisionally interprete d. The results indicate that SPE-GC-MS, and also LVI-GC-MS, have good poten tial for a rapid screening of sediment samples and the identification of mi crocontaminants. The analytical procedures pose no problems, and the on-lin e set-up is user-friendly. (C) 2000 Elsevier Science Ltd. All rights reserv ed.