title: Determination of etoxazole residues in fruits and vegetables by SPE clean-up and HPLC-DAD.
abstract: 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).
authors: Pesticide Residues and Environmental Pollution Department, Agriculture Research Center, Dokki, Giza, Egypt. farag_malhat@yahoo.com
authors: Farag
authors: F
authors: Malhat
authors: Hany
authors: H
authors: Badawy
authors: Dalia
authors: D
authors: Barakat
authors: Ayman
authors: A
authors: Saber
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005506:Food Contamination / Q000032:analysis; D005638:Fruit / Q000737:chemistry*; D010080:Oxazoles / Q000032:analysis* / Q000302:isolation & purification*; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification*; D052616:Solid Phase Extraction / Q000379:methods*; D014675:Vegetables / Q000737:chemistry*
chemical_list: D010080:Oxazoles; D010573:Pesticide Residues; C508136:etoxazole