Determination of triazines residues in fruits and vegetables: Methods comparison of ultrasonic solvent extraction with and without solid phase clean-up

Hopewell Mnyandu ◽  
Precious Mahlambi
2005 ◽  
Vol 88 (3) ◽  
pp. 729-735
Xionghai Yi ◽  
Yitong Lu

Abstract A rapid and simple method using accelerated solvent extraction and solid-phase extraction cleanup was developed and validated for the determination of 15 organophosphorus pesticides in ginkgo leaves by capillary gas chromatography with flame photometric detection. The pesticides were extracted at 100°C under 1500 psi pressure in <20 min. The average recovery from 10 g ginkgo leaves, fortified at 3 levels ranging from 0.05 to 1.00 mg/kg, was 95.2% with a relative standard deviation of 4.6%. The limits of detection ranged from 1.11 × 10−3 mg/kg (dimethoate) to 4.44 × 10−3 mg/kg (dichlorvos). The proposed method showed acceptable accuracy and precision while minimizing environmental concerns, time, and labor. Furthermore, the method could be easily applied to the monitoring of these 15 organophosphorus pesticides in ginkgo leaves.

Abookleesh L Frage , Almrhag M. Omar , Zatout M. Massoud

Headspace solid phase microextraction, fundamental& principle with its application on the determination of various pesticides are reviewed in this article. Pesticides extraction as a sample preparation step prior to subsequent analysis is aimed to achieve a reliable and accurate determination of this contaminants residue in food. Fast and high efficiency extraction process with free solvent consumption and overall cost is achieved through headspace solid phase micro extraction. HSPME is an equilibrium process which depends on the physio-chemical properties of the analyte to be extracted. Sample preparation and extraction condition such as fiber coating, temperature, time etc, have a direct impact on the extraction efficiency and sensitivity of headspace technique.

2000 ◽  
Vol 83 (3) ◽  
pp. 698-713 ◽  
Julie Fillion ◽  
François Sauvé ◽  
Jennifer Selwyn

Abstract A method is described for the determination of 251 pesticide and degradation product residues in fruit and vegetable samples. Extraction of the sample with acetonitrile is followed by a saltingout step. Co-extractives are removed by passing a portion of the acetonitrile extract through an octadecyl (C18) solid-phase extraction cleanup cartridge and then, in a second cleanup, through a carbon cartridge coupled to an amino propyl cartridge. Determination is by gas chromatography with mass-selective detection in the selected-ion monitoring mode, and by liquid chromatography with post-column reaction and fluorescence detection for N-methyl carbamates. The method has been used for analysis of various fruits and vegetables, such as apple, banana, cabbage, carrot, cucumber, lettuce, orange, pear, pepper, and pineapple. Limits of detection range between 0.02 and 1.0 mg/kg for most compounds. Over 80% of the compounds have a limit of detection of ≤0.04 mg/kg.

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