Novel approach to improve the detection of colchicine via online coupling of ionic liquid-based single-drop microextraction with capillary electrophoresis.

A novel approach based on ionic liquid-single-drop microextraction (IL-SDME) online coupling with capillary electrophoresis (CE) was used to determine a toxic alkaloid--colchicine. The IL-SDME procedure was optimized by extraction solvent, drop volume controlling, sample volume and pH, extraction time, and ionic strength. Under optimum conditions, enrichment factor was as much as 41-fold with a relative standard deviation of 2.8% (n = 3). Linear range of response was observed from 1 to 100 μg/mL, with detection limit of 0.25 μg/mL and correlation coefficient (R(2) ) of 0.9994. The extraction of colchicine from spiked Lanzhou lily sample was performed and obtaining good result with an average recovery rate of 102.4 and 98.8% at 5 and 50 μg/mL, respectively. Comparing with the previous methods, IL-SDME-CE is really a convenient, economical, and environmentally benign way for determining colchicine.