Benzotriazole and its derivatives are toxic heterocyclic compounds which are nowadays indispensable for industry. They have been found in environment, causing harmful effects on plants, aquatic organisms, and humans. Their determination usually includes extraction and preconcentration, coupled to sensitive analytical techniques, such as LC-MS/MS, occasionally also HPLC-DAD. One of the existing microextraction techniques is hollow fiber microextraction (HFME), which was used in this work for extraction of six polar benzotriazoles from tap water and further from different river samples. Due to efficient preconcentration, this technique provides high enrichment factors and is a good substitute for classical techniques. Additionally, with the use of HFME, the consumption of harmful organic solvents is decreased to a minimum.
In this work, pH of the sample and concentration of EDTA added as a ligand for metal ions in tap water were optimized. Furthermore, impact of organic solvent (methanol) on extraction efficiency was examined. Optimization was carried out with liquid chromatography coupled with diode array detector (HPLC-DAD). The most efficient extraction was achieved when the pH of the sample was 6 and 100 μL of 0.1 M EDTA was added.
After optimization, matrix effects for the determination of benzotriazoles in Glinščica river water were estimated at two concentration levels: 0.1 mg/L and 2 mg/L. Analyses were carried out with liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Matrix effects were considerable, which can be the consequence of other compounds present in the extract.
Finally, the optimized HFME method was used for determination of polar benzotriazole concentrations in river Krka and Ljubljanica. Analyte concentrations were mostly below limit of detection (LOD) of the method, expect for concentrations of BTZ, ClBZ and DMBZ in Ljubljanica, sampled behind the wastewater treatment plant.
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