Multiresidue Analysis of Pesticides in Fruits and Vegetables Using Solid-Phase Extraction and Gas Chromatographic Methods

Abstract

Experimental Reagents and solutionsAll solvents used were of HPLC grade. Methanol, acetone, ethyl acetate, acetonitrile, hexane and diethyl ether were purchased from Fischer Scientific, Loughborough, UK. Deionized water and hexane were filtered through a 0.45-μm membrane filter purchased from Millipore. Anhydrous sodium sulfate was purchased from J. T. Baker, NJ, USA.The use of high-purity reagents and solvents helps to minimize interference problems. The pesticide standards (acephate, dimethoate, malathion, diazinon, quinalphos, chlorpyrifos, profenofos, α-endosulfan, b-endosulfan, chlorothalonil and carbaryl) were 90.0 -99.5% pure and purchased from AccuStandard Inc. New Haven, CT, USA.All pesticides were dissolved in hexane at 1000 mg/kg concentrations as stock solutions. A mixture containing 0.01 -0.5 mg/kg of each pesticide in hexane was prepared from the stock solutions and as the working solution. In order to avoid any influence on the results from the possible degradation of pesticides, the working solution was freshly prepared every day.1-Chloro-4-fluorobenzene (1 mg/kg) was used as an internal standard to compensate for any sample and injection volume changes, and was added to the vial prior to GC analysis.

A review on sample preparation and chromatographic determination of acephate and methamidophos in different samples

“…Another GC based method was developed for the sensitive determination of acephate and other organophosphate pesticides by using 5% acetone in hexane as extracting solvent and 1-chloro-4-fluorobenzene as an internal standard in fruits and vegetables. The limit of detection by the method was found in between 0.005 and 0.01 mg/kg and the limit of quantification was 0.01 mg/kg (Lal et al, 2008).…”

Quantification of Pyrethroid Residue in Food, Agricultural and Biological Samples

“…MADHURANI SHUKLA 1,* and KISHORE K. TIWARI 2 chromatography, HPLC-MS [13][14][15] and gas chromatography [16][17][18][19] etc. Several spectrophotometric methods have also been reported for the determination of cypermethrin and fenvalerate insecticides.…”

Simultaneous preconcentration of polar and non‐polar organophosphorus pesticides from water samples by using a new sorbent based on mesoporous silica

“…Method simplification and miniaturization are modern trends in analytical chemistry . SPE is a low‐cost, green, simple and convenient sampling method in comparison to LLE , which had been used successfully as a desirable technique for the preconcentration and clean‐up of pesticides from different samples . In the SPE method, the adsorbents are of major importance because they provide the capacity, selectivity and stability.…”