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Objective To develop a method for determination of 18 organophosphorous and carbamate pesticides in human plasma by UPLC-MS/MS. Methods Following deproteinization by acetonitrile, an aliquot of the biological sample was injected into a C18 column(1.7μm 2.1×50mm) using 5mmol/L Ammonium acetate-methanol as the mobile phase with the flow rate of 0.3mL/min, the injection volume was 10μL. Electro spray ionization(ESI) Indicators source was applied and operated in positive ion mode, and multiple reaction monitoring(MRM) mode was used to quantify. Results The limits of detection(LODs) in human plasma ranged from 0.1 to 40ng/mL, and the limits of quantitation(LOQs) ranged from 0.5 to 50ng/mL. An excellent linearity was observed for these LOQs up to 50ng/mL. The average extraction recoveries were with in 64.3%~111.9%, relative standard deviation(RSD) is 3.9%~10.3%. Conclusion This method is specific, sensitive and accurate, and can be used to detect pesticides in forensic.
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Arapidscreeningmethodforthedeterminationofcarbamatepesticides(CBPs)residuesin vegetables by measuring acetylcholinesterase ( AChE ) inhibition rate using electrospray ionization mass spectrometry ( ESI-MS ) has been established. After pretreatment by QuEChERS method, sample solution reacts with AChE using acetylthiocholine as substrate. AChE inhibition rate was calculated by determination of the conversion of substrate to product ( thiocholine) using ESI-MS. The temperature, time and concentration conditions of enzymatic reactions have been optimized. The relationship between the concentration of 10 kinds of common CBPs and AChE inhibition rate was researched. Matrix effects of real vegetables were studied. The limit of detection ( LOD) , which was measured by 3 times of enzyme inhibition rate of pesticide-free vegetable samples, was 0. 01-0. 05 mg/kg. The results showed that the method was better than the current national standard method of china for rapid screening of pesticide residues and fully meet the requirements of maximum residue limits( MRL) for pesticides in food of national food safety standard. False positive results were avoided effectively due to its good ability of resistance matrix interference. The reliability was proved by analyzing vegetables with liquid chromatography-tandem mass spectrometry. The method is simple, rapid, sensitive, reliable, and can be used for the rapid, high-throughput screening of CBPs in vegetables.
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Objective To establish a method for determination of organophosphorus and carbamate pesticide residues in water by GC-MS.Methods Twelve kinds of organophosphorus and carbamate pesticide residues were determined with GC-MS with methylenechloride and petroleum ether(4∶1) as extraction solvent.Results The linear ranges of 12 kinds of pesticides were perfect in the range of 0.01-1.0?g/ml,r≥0.997,the average rates of recovery were 76.0%-111.0%,and RSD were 5.20%-9.20%,the lowest limit detection(S/N=3) of dichlorvos,chinomethionate,parathion,bromophos,carbophenothion,fenthion,isoprocarb,pirimicarb,aminocarb,thiobencarb,pendimethalin,malathion was 0.009,0.003,0.008,0.001,0.003,0.003,0.0025,0.009,0.005,0.010,0.010,0.006 ?g/ml respectively.Conclusion This method is simple,rapid,sensitive and can be applied to the simultaneous determination of 12 kinds of organophosphorus and carbamate pesticides in the water.