پديدآورندگان :
Farajzadeh Mir Ali mafarajzadeh@tabrizu.ac.ir Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran, mafarajzadeh@yahoo.com / , Behboudi Khiavi Elahe Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran , Feriduni Behruz Department of Analytical Chemistry, Faculty of Chemistry, University of Tabriz, Tabriz, Iran
چكيده فارسي :
Phenols are aromatic components which contain one or more hydroxyl groups that are attached to an aromatic ring. The chemical properties of phenols are unique and are used widely in industry [1]. Owing to the increasing production and application of these compounds, they are found in ground waters, rivers, and drinking waters [2]. Due to their toxicity, carcinogenicity and persistence, some of them have been included in the lists of priority pollutants of several countries and are required to be determined [3]. Homogeneous liquid–liquid extraction (HLLE) that extracts the desired solutes existing in a homogeneous aqueous solution into a water–immiscible solvent formed by each kind of phase separation phenomenon [4]. In 2006, Assadi and coworkers developed a novel LPME technique termed dispersive liquid–liquid microextraction (DLLME) [5], which is based on a ternary component solvent system. Some advantages of DLLME are simplicity of operation, rapidity, low sample volume, low cost, and relatively high enrichment factors. In this study, an efficient, simple, and fast method has been introduced for the derivatization, extraction, and preconcentration of some phenolic compounds (phenol, o–, m– and p–cresol, 4–chlorophenol, and 2–nitrophenol) from wastewater samples and their determination by gas chromatography–flame ionization detection. In this method, initially the phenolic compounds are derivatized with acetic anhydride in an alkaline pH. In the following, the derivatized analytes are extracted into mL–volume of acetonitrile during homogeneous liquid–liquid extraction and further enrichment of the target analytes are accomplished by their extraction into µL–volume of 1,1,2–trichloroethane through dispersive liquid–liquid microextraction step. Effective parameters controlling the performance of the proposed method such as type and volume of derivatization agent and catalyst, derivatization reaction time, type and volume of extraction/disperser solvent in homogeneous liquid–liquid extraction, and type and volume of extraction solvent and salt addition in dispersive liquid–liquid microextraction are optimized. Under optimum extraction conditions linear range of the proposed method was obtained in the range of 0.7–4000 µg L–1. Limits of detection and quantification were in the ranges of 0.07–0.20 and 0.23–0.70 µg L–1, respectively. Enrichment factors and extraction recoveries were ranged from 220 to 440 and 44 to 88%, respectively.
