In order to find the effective method to reduce pesticide residues in vegetables, and promote the healthy development of vegetable industry. The paper used chlorothalonil, fenvalerate, dimethoate widely used pesticide...In order to find the effective method to reduce pesticide residues in vegetables, and promote the healthy development of vegetable industry. The paper used chlorothalonil, fenvalerate, dimethoate widely used pesticides as experimental material, using GC method to measure residual dynamics of vegetable pesticide. The results show that： fenvalerate, dimethoate, chlorothalonil pesticide residues in lettuce was higher than that tomato in the application day, respectively reach at 42.9%, 44.9%, 57.8%, pesticide degradation rate in open land were significantly higher than those in greenhouse within 5-20 days. The test showed that： the degradation of pesticide amount is in 8.77%r-19.64% within 1 days. The initial concentration of pesticides on vegetables are relevant with surface area of vegetable edible parts; the degradation speed of pesticide degradation rate in greenhouse vegetable is obviously slower than the open field vegetable; pesticide deposition phenomenon is an important factor affecting the pesticide residues in greenhouse.展开更多
The presence of pesticide residues in food and vegetables is a growing concern for consumers.To monitor these residues reliably,a selective and sensitive multiresidue system has been developed and validated in tomato ...The presence of pesticide residues in food and vegetables is a growing concern for consumers.To monitor these residues reliably,a selective and sensitive multiresidue system has been developed and validated in tomato by gas chromatography–tandem mass spectrometry(GC-MS/MS).Titanium-coated graphite with carbon nanotube(CNT)in acrylonitrile–butadiene–styrene(ABS)used as reversed-dispersive solid-phase extraction materials with modified QuEChERS(Quick,Easy,Cheap,Effective,Rugged,and Safe)method.Titanium-coated graphite with CNT-ABS is synthesized,characterized by X-ray diffraction and scanning electron microscopy.The clean-up performance of titanium-coated graphite with CNT-ABS was demonstrated to be better to primary secondary amine and graphitized carbon black cartridges.The processing of two multiple reaction monitoring transformations for each analyte is done using GC-MS/MS in electron impact mode.Satisfactory purification and recovery effects(74%–100%)of 35 pesticides were achieved in tomato matrices when using 5 mg of titanium-coated graphite ABS-CNT nanocomposite.It was observed that quinolphos and deltamethrin are present above the maximum residue limit.The technique proved to be reliable and sensitive in tomato samples for the routine testing of 35 pesticides.展开更多
文摘In order to find the effective method to reduce pesticide residues in vegetables, and promote the healthy development of vegetable industry. The paper used chlorothalonil, fenvalerate, dimethoate widely used pesticides as experimental material, using GC method to measure residual dynamics of vegetable pesticide. The results show that： fenvalerate, dimethoate, chlorothalonil pesticide residues in lettuce was higher than that tomato in the application day, respectively reach at 42.9%, 44.9%, 57.8%, pesticide degradation rate in open land were significantly higher than those in greenhouse within 5-20 days. The test showed that： the degradation of pesticide amount is in 8.77%r-19.64% within 1 days. The initial concentration of pesticides on vegetables are relevant with surface area of vegetable edible parts; the degradation speed of pesticide degradation rate in greenhouse vegetable is obviously slower than the open field vegetable; pesticide deposition phenomenon is an important factor affecting the pesticide residues in greenhouse.
文摘The presence of pesticide residues in food and vegetables is a growing concern for consumers.To monitor these residues reliably,a selective and sensitive multiresidue system has been developed and validated in tomato by gas chromatography–tandem mass spectrometry(GC-MS/MS).Titanium-coated graphite with carbon nanotube(CNT)in acrylonitrile–butadiene–styrene(ABS)used as reversed-dispersive solid-phase extraction materials with modified QuEChERS(Quick,Easy,Cheap,Effective,Rugged,and Safe)method.Titanium-coated graphite with CNT-ABS is synthesized,characterized by X-ray diffraction and scanning electron microscopy.The clean-up performance of titanium-coated graphite with CNT-ABS was demonstrated to be better to primary secondary amine and graphitized carbon black cartridges.The processing of two multiple reaction monitoring transformations for each analyte is done using GC-MS/MS in electron impact mode.Satisfactory purification and recovery effects(74%–100%)of 35 pesticides were achieved in tomato matrices when using 5 mg of titanium-coated graphite ABS-CNT nanocomposite.It was observed that quinolphos and deltamethrin are present above the maximum residue limit.The technique proved to be reliable and sensitive in tomato samples for the routine testing of 35 pesticides.
