No abstract

& A sensitive, specific, and rapid liquid chromatography tandem mass spectrometry (HPLC-MS= MS) method for the determination of lumefantrine (LF) and its metabolite desbutyl-lumefantrine (DLF) was developed and validated over a concentration range of 2-2000 ng=mL using 100 lL of plasma. After a simple solvent precipitation procedure, the samples were loaded onto Oasis HLB 1cc (30 mg) extraction columns. Separation was achieved using XTerra RP18 (2.1 mm  100 mm, 5.0 lm) column with a binary gradient solvent system consisting of 0.1% formic acid in water (solvent A) and acetonitrile (solvent B). Mass detection was performed using a triple quadrupole mass spectrometer operating in positive electrospray ionization mode. The elution of LF (530.2!512.4), DLF (472.3!454.2) and HF (500.3!142.2) was monitored using multiple reaction monitoring. The extraction recovery of LF, DLF, and HF from human plasma was higher than 85%. The intra-and inter-day precision of LF, DLF, and HF were within 8.0% and the accuracy within AE9.0%. The method was applied to the determination of the concentrations of LF and DLF in patients infected with Plasmodium falciparum malaria on day 3 and 7 after treatment with Lumether.

No abstract

& A sensitive, specific, and rapid liquid chromatography tandem mass spectrometry (HPLC-MS= MS) method for the determination of dapsone, chlorproguanil, and their metabolites was developed and validated over a concentration range of 2-2000 ng=mL using 200 lL of plasma. After a simple solvent precipitation procedure, the supernatant was analyzed directly by HPLC-MS=MS method using an XTerra RP18 (2.1 mm  100 mm, 5.0 lm) column with mobile phase consisting of acetonitrile-0.1% formic acid in water (75:25, v=v, pH 3.0) in an isocratic mode at a flow rate of 0.3 mL=min. Mass detection was performed using a triple quadrupole mass spectrometer operating in positive electrospray ionization mode. The elution of chlorproguanil (CPG, 288 ->204), chlorcycloguanil (CCG, 286 ->229), dapsone (DDS, 249 ->156), monoacetyldapsone (MADDS, 291 ->156), and trimipramine-D 3 (TMP-D 3 , 298 ->103) was monitored using multiple reaction monitoring. The lower limit of detection for CPG, CCG, DDS, and MADDS was 0.5 ng mL À1 while the limit of quantification was 2 ng mL À1 in human plasma. The extraction recovery of CPG, CCG, DDS, MADDS, and TMP-D 3 from human plasma was higher than 87%. The method may find its application in therapeutic monitoring of these compounds in biological matrix.