HEADSPACE SOLID-PHASE MICROEXTRACTION FOR THE DETERMINATION OF VOLATILE AND SEMIVOLATILE POLLUTANTS IN WATER AND AIR

In this work we report the use of solid-phase microextraction (SPME) t o extract and concentrate water-soluble volatile as well as semi-volat ile pollutants. Both methods of exposing the SPME fibre were utilised: immersion in the aqueous solution (SPME) and in the headspace over th e solution (HSSPME). The proposed HSSPME procedure was compared to con ventional static headspace (HS) analysis for artificially spiked water as well as real water samples, which had been, equilibrated with vari ous oil and petroleum products. Both techniques gave similar results b ut HSSPME was much more sensitive and exhibited better precision. Dete ction limits were found to be in the sub-ng/ml level, with precision b etter than 5% R.S.D. in most cases. To evaluate the suitability of SPM E for relatively high contamination level analysis, the proposed HSSPM E method was applied to the screening of run-off water samples that ha d heavy oil suspended in them from a tire fire incident. HSSPME result s were compared with liquid-liquid extraction. Library searches were c onducted on the resulting GC-MS total ion chromatograms to determine t he types of compounds found in such samples. Both techniques found sim ilar composition in the water samples with the exception of alkylnapht halenes that were detected only by HSSPME. A brief study was carried o ut to assess using SPME for air monitoring. By sampling and concentrat ing the volatile organic compounds in the coating of the SPME fibre wi thout any other equipment, this new technique is useful as an alternat ive to active air monitoring by means of sampling pumps and sorbent tu bes. (C) 1998 Elsevier Science B.V All rights reserved.