Fibre selection based on an overall analytical feature comparison for the solid-phase microextraction of trihalomethanes from drinking water.
This paper describes the optimization of solid-phase microextraction (SPME) conditions for three different fibres (Carboxen-polydimethylsiloxane (CAR-PDMS), divinylbenzene-Carboxen-polydimethylsiloxane (DVB-CAR-PDMS) and polydimethylsiloxane-divinylbenzene (PDMS-DVB)) used to determine trihalomethanes (THMs) in water by headspace solid-phase microextraction and gas chromatography (HS-SPME-GC). The influence of temperature and salting-out effect was examined using a central composite design for each fibre. Extraction time was studied separately at the optimum values found for temperature and sodium chloride concentration (40 degrees C and 0.36g mL-1). The HS-SPME-GC-MS method for each fibre was characterised in terms of linearity, detection (LOD) and quantification (LOQ) limits and repeatability. The fibre PDMS-DVB was selected as it provided a broader linear range, better repeatability and lower detection and quantification limits than the others, particularly CAR-PDMS fibre. The accuracy of the proposed method using the PDMS-DVB fibre was checked by a recovery study in both ultrapure and tap water. A blank analysis study showed the absence of memory effects for this fibre. The reproducibility (expressed as a percentage of relative standard deviation) was 6-11% and the detection limits were between 0.078 and 0.52microgL-1 for bromoform and chloroform, respectively. Finally, the method was applied to determine THM concentration in two drinking water samples.
San Juan
Pedro Manuel
PM
Department of Chemistry, University of La Rioja, C/Madre de Dios 51, 26006 Logroño (La Rioja), Spain.
Carrillo
José David
JD
Tena
María Teresa
MT
D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D052617:Solid Phase Microextraction / Q000379:methods*; D022882:Trihalomethanes / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000032:analysis
D022882:Trihalomethanes; D014874:Water Pollutants, Chemical