Analysis of filter-paper-absorbed, finger-stick blood samples for chloroquine and its major metabolite using high-performance liquid chromatography with fluorescence detection.

Methodology has been developed to facilitate the collection, transport, and analysis of blood samples in studies of chloroquine absorption and metabolism. The method utilizes high-performance liquid chromatography (HPLC) with fluorescence detection to quantify chloroquine and its major metabolite, desethylchloroquine, in 100-microliters quantities of blood collected on filter paper. Detection limits are 5 ng/ml for both analytes. No loss of either analyte occurred from filter-paper-collected blood spots stored over a twelve-weeks' period at room temperature. Filter-paper-collected, finger-stick blood spots give values for each analyte comparable to corresponding determinations on venous, whole-blood samples. The HPLC mobile phase selected has general applicability to the separation of antimalarial drugs. The methodology permits effective assessment of chloroquine prophylaxis compliance and parasite drug resistance in remote, malaria-endemic regions.