Dispersive liquid-liquid microextraction based on solidification of floating organic drop combined with field-amplified sample injection in capillary electrophoresis for the determination of beta(2)-agonists in bovine urine

作者：Us Murat Faruk; Alshana Usama; Lubbad Ibrahim; Goger Nilgun G; Ertas Nusret^*

来源：Electrophoresis, 2013, 34(6): 854-861.

DOI：10.1002/elps.201200348

• Beta(2)-agonists
• Bovine urine
• Capillary electrophoresis
• Dispersive liquidliquid microextraction
• Solidification of floating organic drop

Dispersive liquidliquid microextraction based on solidification of floating organic drop (DLLMESFO) was for the first time combined with field-amplified sample injection (FASI) in CE to determine four 2-agonists (cimbuterol, clenbuterol, mabuterol, and mapenterol) in bovine urine. Optimum BGE consisted of 20 mM borate buffer and 0.1 mM SDS. Using salting-out extraction, 2-agonists were extracted into ACN that was then used as the disperser solvent in DLLMESFO. Optimum DLLMESFO conditions were: 1.0 mL ACN, 50 L 1-undecanol (extraction solvent), total extraction time 1.5 min, no salt addition. Back extraction into an aqueous solution (pH 2.0) facilitated direct injection of 2-agonists into CE. Compared to conventional CZE, DLLMESFOFASICE achieved sensitivity enhancement factors of 411046 resulting in LODs in the range of 1.8037.0 g L1. Linear dynamic ranges of 0.1510.0 mg L1 for cimbuterol and 151000 g L1 for the other analytes were obtained with coefficients of determination (R2) 0.9901 and RSD% 5.5 (n = 5). Finally, the applicability of the proposed method was successfully confirmed by determination of the four 2-agonists in spiked bovine urine samples and accuracy higher than 96.0% was obtained.

• 出版日期2013-3