The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organop- hosphorus pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) (G...The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organop- hosphorus pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) (GC-NPD); to select an appropriate solvent system; to conduct a comparison of sonication and shaking extractions; and to select an appropriate procedure for extracting organophosphorus pesticides from soils. Procedure I consisted of n-hexane or petroleum ether together with acetone used as solvents, while Procedure contained several solvents including acetone, methanol, dichloromethane, and n-hexane or petroleum ether. Experimental results indicated that a mixture of petroleum ether/acetone (2:1, v/v) could be used in place of n-hexane/acetone (2:1, v/v) as it was a less expensive solvent system. In addition, shaking under a water bath at 20 °C was more effective than sonication. Also, Procedure I was more effective, safer, and more timesaving than Procedure Procedure I was applied to three soil types of different organic matter content, with recoveries of the OPPs from the yellow-brown soils, which had a higher organic matter content, being lower than those from the yellow and red soils.展开更多
Pesticides have done a great service to human, but their use is not safe for public health. Apart from pesticides acute toxicity, their chronic toxicity can cause various problems for human health. The objective of th...Pesticides have done a great service to human, but their use is not safe for public health. Apart from pesticides acute toxicity, their chronic toxicity can cause various problems for human health. The objective of this work was to validate a liquid-liquid extraction method, which allows a fairly reliable analysis of pesticides using gas chromatography-spectrometry mass （GC/MS） in toxicology laboratory at National Institute of hygiene, Rabat Morocco. The equipment required to perform these analyzes are the biological matrices （blood, gastric fluid）, in which the authors have doped the Organophosphorus pesticides such as Chlorpyrifos, Dichlorvos and Organochlorine pesticide： dichlorodiphenyltrichloroethane （DDT） and Heptachlor. After extracting the mixture with toluene, the supernatant was collected after centrifugation and concentrated in a small volume of 1.5 mL and then analyzed in GC/MS. After analyzing, the authors found that the yields of each pesticide in samples are significant; respectively they represented 73.4% of Chlorpyrifos, 70.8% of Dichlorvos, 47.8% of DDT and 71.6% of Heptachlor. The blood has a strong link with the most pesticides, where it＇s important to use the GC/MS to identify these products. The extraction with toluene was effective, especially to OP, but it＇s also sensitive to OC.展开更多
基金1Project supported by the Outstanding Youth Fund of the National Natural Science Foundation of China (No. 40325001),the National Key Basic Research Support Foundation of China (Nos. 2002CB415203 and 2002CB410805) and the Knowl-edge Innovation Program of
文摘The objectives of this study were to optimize instrumental parameters and conditions for analysis of selected organop- hosphorus pesticides (OPPs) by gas chromatography (GC) with nitrogen-phosphorus detection (NPD) (GC-NPD); to select an appropriate solvent system; to conduct a comparison of sonication and shaking extractions; and to select an appropriate procedure for extracting organophosphorus pesticides from soils. Procedure I consisted of n-hexane or petroleum ether together with acetone used as solvents, while Procedure contained several solvents including acetone, methanol, dichloromethane, and n-hexane or petroleum ether. Experimental results indicated that a mixture of petroleum ether/acetone (2:1, v/v) could be used in place of n-hexane/acetone (2:1, v/v) as it was a less expensive solvent system. In addition, shaking under a water bath at 20 °C was more effective than sonication. Also, Procedure I was more effective, safer, and more timesaving than Procedure Procedure I was applied to three soil types of different organic matter content, with recoveries of the OPPs from the yellow-brown soils, which had a higher organic matter content, being lower than those from the yellow and red soils.
文摘Pesticides have done a great service to human, but their use is not safe for public health. Apart from pesticides acute toxicity, their chronic toxicity can cause various problems for human health. The objective of this work was to validate a liquid-liquid extraction method, which allows a fairly reliable analysis of pesticides using gas chromatography-spectrometry mass （GC/MS） in toxicology laboratory at National Institute of hygiene, Rabat Morocco. The equipment required to perform these analyzes are the biological matrices （blood, gastric fluid）, in which the authors have doped the Organophosphorus pesticides such as Chlorpyrifos, Dichlorvos and Organochlorine pesticide： dichlorodiphenyltrichloroethane （DDT） and Heptachlor. After extracting the mixture with toluene, the supernatant was collected after centrifugation and concentrated in a small volume of 1.5 mL and then analyzed in GC/MS. After analyzing, the authors found that the yields of each pesticide in samples are significant; respectively they represented 73.4% of Chlorpyrifos, 70.8% of Dichlorvos, 47.8% of DDT and 71.6% of Heptachlor. The blood has a strong link with the most pesticides, where it＇s important to use the GC/MS to identify these products. The extraction with toluene was effective, especially to OP, but it＇s also sensitive to OC.
