5697

5319

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده شيمي

1389

سيزده،79ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمد سراجي، محمد تقي جعفري

21/12/89

علي اصغر انصافي،تقي خياميان

شيمي

ID5319

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Simultaneous determination of phenoxyacid herbicides in water samples using microextraction in packed syringe and ion electrospray ionization ion mobility spectrometry Shila Yousefi s yousefi@ch iut ac ir December 2010 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Lanquage Farsi Supervisers Assoc Prof Mohammad Saraji saraji@cc iut ac ir Assist Prof Mohammad Taghi Jafari jafari@cc iut ac ir Abstract In this research combination of microextraction in packed syringe MEPS and negative mode electrospray ionization ion mobility spectrometry ESI IMS was used for the first time for preconcentration and determination of three phenoxyacid herbicides in environmental water samples simultaneously The MEPS is a novel technique for miniaturized SPE MEPS is very promising because it is fast simple and it requires small volume of samples to produce comparable results to conventional SPE technique MEPS was performed by using 1 4 mg of solid phase material Oasis HLB inserted in to a 250 L gas tight syringe The solid phase material is fixed in the syringe as a plug using polyethylene frits Sample preparation is performed on the sorbent Several factors affecting the performance of MEPS such as water sample pH elution volume sample loading volume and its speed were studied Sample pH was adjusted with 0 02 M sulphuric acid at pH 2 In MEPS sorbent was conditioned first with methanol and then with purified water 2 200 L each solvent before being used for the first time The water sample 200 L in each cycle was drawn through the syringe and discard in waste extract discard with speed of 2 5 L s The extraction cycle was repeated 7 times This step was performed by a variable speed stirring motor which was attached to a circular plate The solid phase was then washed with 100 L purified water to remove interference such as sulphuric acid The sorbent was dried by a gentle stream of nitrogen gas during 5 minutes The analytes were then eluted with 20 L methanol at speed of 1 0 L s The eluent was injected directly to ESI IMS injector The cleaning of the solid phase was performed using 5 200 L methanol then 5 200 L purified water The limits of detection were ranged from 0 04 to 0 08 g L and the relative standard deviations were under 10 The applicability of the proposed methods was demonstrated by analyzing spiked real water samples Recoveries were obtained as higher as 76 to 102 Key Words Microextraction in packed syringe Electrospray ionization ion mobility spectrometry Water samples Phenoxyacid herbicides

محمد سراجي، محمد تقي جعفري

علي اصغر انصافي،تقي خياميان