Simple and rapid HPLC of quinine, hydroxychloroquine, chloroquine, and desethylchloroquine in serum, whole blood, and filter paper-adsorbed dry blood.

A simple high-performance liquid chromatographic assay for the measurement of quinine, hydroxychloroquine, chloroquine, and desethylchloroquine in small volumes (50-200 microL) of serum, whole blood, or filter paper-adsorbed dry blood was developed. The analytes are isolated by liquid-liquid extraction and chromatographed on a sulfophenylpropyl-modified silica column under isocratic conditions. The column effluent is monitored by fluorimetry (excitation wavelength, 215 nm; no emission filter). The limit of quantitation is 0.005-0.01 mg/L for chloroquine and hydroxychloroquine and 0.05 mg/L for quinine. No interference from other antimalarial drugs or other compounds commonly used has been observed. Quantitative results can be obtained within 1 hour of receipt of the sample.