Determination of etoxazole residues in fruits and vegetables by SPE clean-up and HPLC-DAD

• Published in: Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes Pesticides, food contaminants, and agricultural wastes, 2013-05, Vol.48 (5), p.331-335
• Main Authors: Malhat, Farag, Badawy, Hany, Barakat, Dalia, Saber, Ayman
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Analytical chemistry; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Chromatography; Chromatography, High Pressure Liquid - methods; Control; Etoxazole in food stuff; Extraction processes; Food Contamination - analysis; Fragaria; Fruit - chemistry; Fruits; Fundamental and applied biological sciences. Psychology; HPLC-DAD; Oxazoles - analysis; Oxazoles - isolation & purification; Pesticide Residues - analysis; Pesticide Residues - isolation & purification; Pesticides; Phaseolus vulgaris; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; solid phase extraction; Solid Phase Extraction - methods; Vegetables; Vegetables - chemistry
• ISSN: 0360-1234; 1532-4109
• DOI: 10.1080/03601234.2013.742371

A method for determination of etoxazole residues in apples, strawberries and green beans was developed and validated. The analyte was extracted with acetonitrile from foodstuff and a charcoal-celite cartridge was used for clean-up of raw extracts. Reversed phase high performance liquid chromatography with photodiode array detector (HPLC-DAD) was used for the determination and quantification of etoxazole residues in the studied samples. The calibration graphs of etoxazole in a solvent or three blank matrixes were linear within the tested intervals 0.01-2 mg L −1 , with correlation coefficient of determination >0.999. The combined solid phase extraction (SPE) clean-up and the chromatographic method steps were sensitive and reliable for simultaneous determination of etoxazole residues in the studied samples. The average recoveries of etoxazole in the tested foodstuffs were between 93.4 to 102% at spiking levels of 0.01, 0.10, and 0.50 mg kg −1 , with relative standard deviations ranging from 2.8 to 4.7%, in agreement with directives for method validation in residue analyses. The limit of detection (LOD) of the HPLC-DAD system was 100 pg. The limit of quantification of the entire method was 0.01 mg kg −1 .