HOLLOW FIBER LIQUID PHASE MICROEXTRACTION COMBINED WITH HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR PRECONCENTRATION AND DETERMINATION OF CABERGOLINE IN BIOLOGICAL SAMPLES

In this study, a simple and efficient hollow fiber liquid phase microextraction (HF–LPME) method coupled with high performance liquid chromatography has been developed for preconcentration and determination of cabergoline in plasma and urine samples. Cabergoline was extracted from 15 mL of basic sample solution with pH of 10 into an organic extracting solvent (n-octanol) impregnated in the pores of a hollow fiber, and then back-extracted into an acidified aqueous solution in the lumen of the hollow fiber with pH of 3. The extraction was performed due to pH gradient between the inside and outside of the hollow fiber membrane. In order to obtain high extraction efficiency, the parameters affecting the HF–LPME including the type of organic solvent, pH of the donor and acceptor phases, ionic strength, stirring rate, volume ratio of donor to acceptor phase, extraction time, and temperature were studied and optimized. Under the optimized conditions, enrichment factors up to 315 were achieved. The detection limit and relative standard deviation (RSD) (n = 5, c = 2 µg L−1) for cabergoline were 0.01 µg L−1 and 4.5%, respectively. The method was successfully applied to determine the concentration of cabergoline in the plasma and urine samples and satisfactory results were obtained.