J Chromatogr B Analyt Technol Biomed Life Sci 2013 Dec 16;941:116-22. Epub 2013 Oct 16.
Chromatography and Separation Research Unit, Department of Chemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand; Mahidol-Oxford Tropical Medicine Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.