Title of article :
Determination of nitroaromatic explosives in water samples by direct ultrasound-assisted dispersive liquid–liquid microextraction followed by gas chromatography–mass spectrometry
Author/Authors :
Carol Cortada، نويسنده , , Carol and Vidal، نويسنده , , Lorena and Canals، نويسنده , , Antonio، نويسنده ,
Issue Information :
ماهنامه با شماره پیاپی سال 2011
Pages :
7
From page :
2546
To page :
2552
Abstract :
A fast, simple, inexpensive, sensitive, efficient and environmental friendly direct ultrasound-assisted dispersive liquid–liquid microextraction (DUSA-DLLME) procedure has been developed to concentrate five nitroaromatic explosives from water samples prior to quantification by gas chromatography–mass spectrometry (GC–MS). An efficient ultrasonic probe has been used to radiate directly the samples producing very fine emulsions from immiscible liquids. A D-optimal design was used for optimizing the factors and to evaluate their influential upon extraction. The optimum experimental conditions were: sample volume, 10 mL; extraction time, 60 s; cycles, 0.6 s(s−1); power of ultrasound energy, 40% (70 W); and, extractant solvent (chlorobenzene) volume, 20 μL. Under the optimized experimental conditions the method presents good level of repeatability with coefficients of variation under 6% (n = 8; spiking level 10 μg L−1). Calculated calibration curves gave high level of linearity with correlation coefficient values between 0.9949 and 0.9992. Limits of detection were ranged between 0.03 and 0.91 μg L−1. Finally, the proposed method was applied to the analysis of two types of water samples, reservoir and effluent wastewater. The samples were previously analysed and confirmed free of target analytes. At 5 μg L−1 spiking level recovery values ranged between 75 and 96% for reservoir water sample showing that the matrix had a negligible effect upon extraction. However, a noticeable matrix effect (around 50% recovery) was observed for effluent wastewater sample. In order to alleviate this matrix effect, the standard addition calibration method was used for quantitative determination. This calibration method supplied recovery values ranged between 71 and 79%. The same conclusions have been obtained from an uncertainty budget evaluation study.
Keywords :
Nitroaromatic explosives , Direct ultrasound-assisted dispersive liquid–liquid microextraction , Gas chromatography–mass spectrometry , D-optimal design , Expanded uncertainty , water
Journal title :
Talanta
Serial Year :
2011
Journal title :
Talanta
Record number :
1663485
Link To Document :
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