Determination of anti-malaria agent chloroquine using single drop liquid-liquid-liquid microextraction.

A simple, sensitive, and inexpensive single drop liquid-liquid-liquid microextraction combined with isocratic RP-HPLC and UV detection was developed for the determination of anti-malaria drug, chloroquine. The target compound was extracted from alkaline aqueous sample solution (adjusted to 0.5 mol/L sodium hydroxide) through a thin layer of organic solvent membrane and back-extracted to an acidic acceptor drop (adjusted to 0.02 mol/L phosphoric acid) suspended on the tip of a 25 microL HPLC syringe in the organic layer. This syringe was also used for direct injection after extraction. The linear range was 1-200 microg/L. The LOD and LOQ were 0.3 and 1.0 microg/L, respectively. Intra-and inter-day precisions were less than 2.0 and 2.3%, respectively. The real samples were successfully analyzed using the proposed method. The recoveries of spiked samples were more than 94.6%.