شماره ركورد كنفرانس :
3550
عنوان مقاله :
Application of dispersive liquid-liquid microextraction in the determination of remained Diazinon and by-products in a combined Fenton-anaerobic biological treatment process
پديدآورندگان :
Rezaei Ali Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran , Aber Soheil soheil_aber@yahoo.com Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran; , Farajzadeh Mir Ali Department of Applied Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
كليدواژه :
Gas chromatography , Diazoxan
عنوان كنفرانس :
بيست و پنجمين سمينار ملي شيمي تجزيه انجمن شيمي ايران
چكيده فارسي :
In this work dispersive liquid-liquid microextraction followed by gas chromatography equipped with flame ionization detector (DLLME-GC-FID) was used to determine Diazinon concentration before and after coupled Fenton-anaerobic biological treatment. Also, dispersive liquid-liquid microextraction coupled with gas chromatography-mass spectrometry (DLLME-GC-MS) was used for the detection of Diazinon’s by-products after the Fenton and biological oxidation steps. In this extraction method, a mixture of 70 μl chloroform (extraction solvent) and 1.0 ml methanol (disperser solvent) was rapidly injected into the 5.0 ml water sample by syringe [1]. Thereby, a cloudy solution was formed. In fact, the cloudy state was created because of the formation of fine droplets of chloroform, which were dispersed in the sample solution. In this step, the Diazinon in water sample was extracted into the fine droplets of chloroform [2]. After centrifuging (5 min at 6000 rpm), the fine droplets of chloroform were precipitated in the bottom of the conical test tube (50±10 μl). The precipitated phase (1.0 μl) was injected into the GC column. The GC-Mass analysis was utilized to characterize the intermediates such as Cyanthoate, Sulfotep, and Diazoxan which are produced during the Fenton step. It was indicated that Fenton process is not capable to mineralize Diazinon, completely and toxic intermediate compounds such as Diazoxan was produced. So, using the integrated processes including biological and chemical oxidation for complete degradation of these intermediates is necessary. Different experiments were done to reach the optimum condition for the integrated treatment. According to the obtained results, treatment by Fenton process which was done by using 1 ppm Fe2SO4.7H2O and 5 ppm H2O2 within 30 minutes followed by biological treatment within 96 hour led to 89.4% removal of Diazinon. Diazinon concentration was determined at each step by using GC-FID analysis.
