scholarly journals Hollow-Fibre-Supported Dispersive Liquid-Liquid Microextraction for Determination of Atrazine and Triclosan in Aqueous Samples

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Thabiso Letseka ◽  
Mosotho J. George

We report the application of the dispersive liquid-liquid microextraction coupled to hollow-fibre membrane-assisted liquid-phase microextraction and its application for extraction of atrazine and triclosan. Under optimum conditions, namely, 25 μL of a 1 : 4 chlorobenzene : ethyl acetate mixture dispersed in 1 mL of aqueous sample, 10% (m/v) NaCl, a magnetic stirrer speed at 600 rpm, and 10 minutes’ extraction time with toluene-filled fibre as the acceptor phase, the method demonstrates sufficient figures of merit. These include linearity (R2 ≥ 0.9975), intravial precision (%RSD ≤ 7.6), enrichment factors (127 and 142), limits of detection (0.0081 and 0.0169 µg/mL), and recovery from river water and sewerage (96–101%). The relatively high detection limits are attributed to the flame ionization detector which is less preferred than a mass spectrometer in trace analyses. This is the first report of a homogenous mixture of the dispersed organic solvent in aqueous solutions and its employment in extraction of organic compounds from aqueous solutions. It therefore adds yet another candidate in the pool of miniaturised solvent microextraction techniques.

2014 ◽  
Vol 97 (1) ◽  
pp. 183-187 ◽  
Author(s):  
Run-Zhen Fan ◽  
Congyun Liu ◽  
Wenqing Jiang ◽  
Xiaonan Wang ◽  
Fengmao Liu

Abstract Ultrasound-assisted dispersive liquid–liquid microextraction (UA-DLLME) based on solidification of the floating organic solvent droplets (SFO) combined with HPLC was used for determination of five fungicides in fruit juice samples. 1-Dodecanol, which has a low density and low toxicity, was used as the extraction solvent in UA-DLLME. The solidification of floating organic dropletsfacilitates the transfer of analytes from the aqueous phase to the organic phase. This method was easy, quick, inexpensive, precise, and linear over a wide range. Under the optimized conditions, the enrichment factors for a 5 mL fruit juice sample were 25 to 56, and the LODs for the five fungicides ranged from 5 to 50 μg/L. The average recoveries ranged from 71.8 to 118.2% with RSDsof 0.9 to 13.9%. Application of the DLLME-SFO technique allows successful separation and preconcentration of the fungicides at a low concentration level in fruit juice samples.


2009 ◽  
Vol 7 (3) ◽  
pp. 285-290 ◽  
Author(s):  
Aleksandra Prichodko ◽  
Kristina Jonusaite ◽  
Vida Vickackaite

AbstractA hollow fibre liquid phase microextraction for gas chromatographic determination of some p-hydroxybenzoic acid esters has been developed. Chlorobenzene containing tetradecane as internal standard was used for the extraction. Optimized extraction was carried out at room temperature for 40 min in the presence of 0.4 g mL−1 NaCl in the sample solution. Calibration was linear up to 30 mg L−1. Correlation coefficients were 0.996–0.998. Enrichment factors were 21, 95 and 154, and detection limits were 0.20, 0.03 and 0.01 μg mL−1 for methylparaben, ethylparaben and propylparaben, respectively. Reproducibility was acceptable with relative standard deviations up to 11.7%. The technique was tested for water and urine analysis.


2015 ◽  
Vol 68 (3) ◽  
pp. 481 ◽  
Author(s):  
Mostafa Khajeh ◽  
Leyla Azarsa ◽  
Mansoureh Rakhshanipour

In this study, chitosan–zinc oxide nanoparticles were used as an adsorbent matrix for solid-phase extraction and combined with dispersive liquid–liquid microextraction (SPE–DLLME) for determination of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) in water samples. The eluent of SPE was used as the dispersive solvent of the DLLME for further purification and enrichment of the BTEX prior to gas chromatography-flame ionization detector analysis. The effect of variables, including amount of adsorbent, sample and eluent flow rate, type and volume of extraction and dispersive solvent, salt concentration, and extraction time, was investigated and they were optimized. Under the optimum conditions, good linearity for all BTEX with determination coefficients in the range of 0.9993 < r2 < 0.9997, suitable precision (1.4 % < RSD <1.9 %; where RSD refers to relative standard deviation), and low detection limits (0.5–1.1 µg L–1) were achieved. The current chitosan–zinc oxide nanoparticles SPE–DLLME procedure combines the advantages of SPE and DLLME, and was applied for determination of BTEX in water samples and acceptable recoveries were obtained.


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