Daniel BlessbornSusanne RomsingYngve BergqvistNiklas LindegardhHogskolan DalarnaUppsala UniversitetMahidol UniversityCenter for Clinical Research DalarnaNuffield Department of Clinical Medicine2018-09-242018-09-242010-11-01Bioanalysis. Vol.2, No.11 (2010), 1839-184717576199175761802-s2.0-79952521150https://repository.li.mahidol.ac.th/handle/20.500.14594/28610Background: More parasites are becoming resistant to antimalarial drugs, and in many areas a change in first-line drug treatment is necessary. The aim of the developed assay is to help determine drug use in these areas and also to be a complement to interviewing patients, which will increase reliability of surveys. Results: This assay detects quinine, mefloquine, sulfadoxine, pyrimethamine, lumefantrine, chloroquine and its metabolite desethylchloroquine in a 100-μl dried blood spot. Most of the drugs also have long half-lives that make them detectable at least 7 days after administration. The drugs are extracted from the dried blood spot with sequential extraction (due to the big differences in physicochemical properties), solid-phase extraction is used as sample clean-up and separation is performed with gradient-LC with MS ion-trap detection. Conclusion: Detection limits (S/N > 5:1) at 50 ng/ml or better were achieved for all drugs except lumefantrine (200 ng/ml), and thus can be used to determine patient compliance. A major advantage of using the ion-trap MS it that it will be possible to go back into the data and look for other drugs as needed. © 2010 Future Science Ltd.Mahidol UniversityBiochemistry, Genetics and Molecular BiologyChemistryHealth ProfessionsPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.4155/bio.10.147