A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides...A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.展开更多
A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extractio...A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extraction for sample preparation.Rapid qualitative and quantitative analyses was carried out by gas chromatography-mass spectrometry under the selective-ion monitoring mode.The experimental results showed that the correlation coefficients were better than 0.99,the recoveries for spiked standards were 70%-104%,the relative standard deviations were 2.1%-15.9%.展开更多
An efficient and selective analytical method for the determination of 8 organochlorines pesticides residues(α-666,β-666,γ-666,δ-666,op’-DDT,pp’-DDT,pp’-DDD,pp’-DDE) in coffee has been developed.The cof...An efficient and selective analytical method for the determination of 8 organochlorines pesticides residues(α-666,β-666,γ-666,δ-666,op’-DDT,pp’-DDT,pp’-DDD,pp’-DDE) in coffee has been developed.The coffee samples were extracted with hexane-acetone(1 ∶1,by volume) according to a selective extraction step using accelerated solvent extraction(ASE),followed by a clean-up by gel permeation chromatography(GPC) and a column combined with Florisil and GCB.Identification and quantification were performed using gas chromatography with negative chemical ionization mass spectrometric detection(GC-NCI MS).The method detection limits varied between 0.002 and 0.069 ng/g.The calibration curves showed a good linearity for all OCPs(r≥0.999 5) under a concentration of 0.20-50.0 μg/L.When the spiked levels were 0.5 μg/L and 5 μg/L,the average recoveries were range of 94%-110% with RSD of 3.5%-10.6%.The method was accurate,sensitive and suitable for the analysis of pesticides.展开更多
基金The study was financially supported by the National Science and Technology Support Program of China(Grant No.2013BAD16B08).
文摘A convenient,cost-effective and fast method using dynamic microwave-assisted extraction and liquid phase microextraction based on the solidification of a floating drop was proposed to analyze organochlorine pesticides in grains including rice,maize and millet.Twelve samples can be processed simultaneously in the method.During the extraction process,10%acetonitrile-water solutions containing 110μL of n-hexadecane were used to extract organochlorine pesticides.Subsequently,1.0 g sodium chloride was placed in the extract,and then centrifuged and cooled.The n-hexadecane drops containing the analytes were solidifi ed and transferred for determination by gas chromatography-electron capture detector without any further filtration or cleaning process.Limits of detection for organochlorine pesticides were 0.97–1.01μg/kg and the RSDs were in the range of 2.6%–8.5%.The developed technology has succeeded in analyzing six real grains samples and the recoveries of the organochlorine pesticides were 72.2%–94.3%.Compared with the published extraction methods,the developed method was used to analyze organochlorine pesticides in grains,being more environmentally friendly,which is suitable for the daily determination of organochlorine pesticides.
文摘A GC-MS method for the determination of 27 organochlorine pesticides and 15 Pyrethroid pesticides in animal food is established.The method was based on Gel Permeation chromatography combined with solid-phase extraction for sample preparation.Rapid qualitative and quantitative analyses was carried out by gas chromatography-mass spectrometry under the selective-ion monitoring mode.The experimental results showed that the correlation coefficients were better than 0.99,the recoveries for spiked standards were 70%-104%,the relative standard deviations were 2.1%-15.9%.
文摘An efficient and selective analytical method for the determination of 8 organochlorines pesticides residues(α-666,β-666,γ-666,δ-666,op’-DDT,pp’-DDT,pp’-DDD,pp’-DDE) in coffee has been developed.The coffee samples were extracted with hexane-acetone(1 ∶1,by volume) according to a selective extraction step using accelerated solvent extraction(ASE),followed by a clean-up by gel permeation chromatography(GPC) and a column combined with Florisil and GCB.Identification and quantification were performed using gas chromatography with negative chemical ionization mass spectrometric detection(GC-NCI MS).The method detection limits varied between 0.002 and 0.069 ng/g.The calibration curves showed a good linearity for all OCPs(r≥0.999 5) under a concentration of 0.20-50.0 μg/L.When the spiked levels were 0.5 μg/L and 5 μg/L,the average recoveries were range of 94%-110% with RSD of 3.5%-10.6%.The method was accurate,sensitive and suitable for the analysis of pesticides.
