Analysis of cypermethrin residues and its main degradation products in soil and formulation samples by gas chromatography-electron impact-mass spectrometry in the selective ion monitoring mode |
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Authors: | Hasnae Garoiaz Mohammed Berrabah Abderahmane Elidrissi Belkheir Hammouti |
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Institution: | Department of Chemistry, Faculty of Sciences , University Mohamed Premier , Oujda , BP 717- 60000-Morocco |
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Abstract: | A fast, simple and inexpensive sample preparation method based on the matrix solid-phase extraction (SPE) technique is proposed for the isolation of cypermethrin and its metabolite residues from soils. Both the extraction and clean-up procedures were carried out in two steps and target compounds were determined by gas chromatography coupled with electron-impact mass spectrometry (GC-EI/MS). The characteristic ions and fragmentation mechanism of cypermethrin were evaluated by electron impact ionization mass spectrometry (EI/MS). After the optimization of different parameters, such as the extraction solvent, the pesticide was extracted from the matrix with methanol/acetone in a Soxhlet extractor, cleaned up on a Florisil column by elution with a mixture of 30% ethyl acetate in n-hexane and analyzed by gas chromatography-electron impact ionization mass spectrometry (GC-EI/MS) in the selected ion-monitoring mode (SIM) with permethrin as internal standard. Recovery was in the range 77–118% with relative standard deviations (RSD) between 2.5% and 10.2%. The limit of detection (LOD) was 6.5?µg/kg for cypermethrin. The developed method was linear in the injection range 6–30?ng, with correlation coefficients greater than 0.9957. |
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Keywords: | pesticide residues soils formulations cypermethrin solid-phase extraction gas chromatography-mass spectrometry |
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