title: Development of a new microextraction method based on a dynamic single drop in a narrow-bore tube: application in extraction and preconcentration of some organic pollutants in well water and grape juice samples.
abstract: A novel sample preparation technique, the microextraction method based on a dynamic single drop in a narrow-bore tube, coupled with gas chromatography-flame ionization detection (GC-FID) is presented in this paper. The most important features of this method are simplicity and high enrichment factors. In this method, a microdrop of an extraction solvent assisted by an air bubble was repeatedly passed through a narrow-bore closed end tube containing aqueous sample. It has been successfully used for the analysis of some pesticides as model analytes in aqueous samples. Parameters affecting the method's performance such as selection of extraction solvent type and volume, number of extractions, volume of aqueous sample (tube length), and salt effect were studied and optimized. Under the optimal conditions, the enrichment factors (EFs) for triazole pesticides were in the range of 141-214 and the limits of detection (LODs) were between 2 and 112 μg L(-1). The relative standard deviations (C=1000 μg L(-1), n=6) were obtained in the range of 2.9-4.5%. The recoveries obtained for the spiked well water and grape juice samples were between 71 and 106%. Low cost, relatively short sample preparation time and less solvent consumption are other advantages of the proposed method.
authors: Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran. mafarajzadeh@yahoo.com
authors: Mir Ali
authors: MA
authors: Farajzadeh
authors: Djavanshir
authors: D
authors: Djozan
authors: Parisa
authors: P
authors: Khorram
mesh_terms: D053000:Analytic Sample Preparation Methods / Q000379:methods*; D001628:Beverages / Q000032:analysis*; D005591:Chemical Fractionation / Q000379:methods*; D006863:Hydrogen-Ion Concentration; D009930:Organic Chemicals / Q000032:analysis / Q000302:isolation & purification*; D010573:Pesticide Residues / Q000032:analysis / Q000302:isolation & purification*; D012492:Salts / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D013997:Time Factors; D027843:Vitis / Q000737:chemistry*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000302:isolation & purification; D014881:Water Supply
chemical_list: D009930:Organic Chemicals; D010573:Pesticide Residues; D012492:Salts; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water