Özet:

A magnetic solid-phase extraction method has been developed for the extraction and analysis of some fungicides in environmental water samples. Azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin were the target fungicides selected. First, a carbon material was obtained from the raw coal sample collected from Zonguldak region by ash removal process and then a magnetic C/Fe3O4 composite was produced from the carbon material using a single-step thermal method. The magnetic C/Fe3O4 composite was characterized by N2 adsorption-desorption, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. This composite was then used as an adsorbent for the magnetic solid-phase extraction of fungicides from water samples followed by high-performance liquid chromatographic analysis. Experimental parameters affecting the extraction efficiency such as adsorbent amount, type and volume of desorption solvent, adsorption and desorption time, ionic strength, and pH were optimized. Under the optimized conditions, the extraction efficiency for azoxystrobin, chlorothalonil, cyprodinil and trifloxystrobin was found to be 71%, 44%, 41% and 70%, respectively. The method detection limits for fungicides were found to be in the range of 0.4-1.1 µg L-1. The relative standard deviations were found to be lower than 6.6% and 6.9% for intra-day and inter-day precisions, respectively. The extraction of related fungicides from water samples collected from Zonguldak region was carried out efficiently. The recoveries obtained from spiked water samples were in the range of 71–106%.

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