Homogeneous liquid-liquid extraction of trace amounts of mononitrotoluenes from waste water samples |
| |
Authors: | Ebrahimzadeh Homeira Yamini Yadollah Kamarei Fahimeh Shariati Shahab |
| |
Affiliation: | a Department of Chemistry, Shahid Beheshti University, Evin, Tehran, Iran b Department of Chemistry, Tarbiat Modarres University, P.O. Box 14115-175, Tehran, Iran |
| |
Abstract: | Homogeneous liquid-liquid extraction method was studied based on a phase separation phenomenon in a ternary solvent system. According to this procedure, mononitrotoloenes were extracted by single-phase extraction in a water/methanol/chloroform, homogeneous ternary solvent system. Methanol and chloroform were used as consolute and extraction solvents, respectively. The homogeneous solution was broken by the addition of salt and a cloudy solution was formed. After centrifugation, the fine droplets of the extraction solvent were sedimented in the bottom of the conical test tube. Analysis of the extracts was carried out by gas chromatography. The optimization procedure was performed using Box-Behnken design. The variables involved were: sample and extraction solvent volumes, consolute solvent volume and phase separator reagent concentration. Optimum results were obtained under the following conditions: sample volume of 5 mL, extraction solvent volume of 55 μL, consolute solvent volume of 1 mL and phase separator reagent concentration; 5% (w/v). Under these conditions, the enrichment factors of 354, 311 and 300, dynamic linear ranges of 0.5-500, 1-500 and 1-500 μg L−1, and limit of detections (LODs) of 0.09, 0.09 and 0.1 μg L−1 were obtained for o-nitrotoluene, m-nitrotoluene and p-nitrotoluene, respectively. Finally, the method was successfully applied to the extraction and determination of MNTs in the waste water samples in the range of micrograms per liter with R.S.Ds. < 13.2%. |
| |
Keywords: | Homogeneous liquid-liquid extraction Box-Behnken design Mononitrotoluenes Gas chromatography |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|