J. TarningT. SingtorojA. AnnerbergM. AshtonY. BergqvistN. J. WhiteN. P J DayN. LindegardhGoteborg University, Sahlgrenska AcademyMahidol UniversityHogskolan DalarnaNuffield Department of Clinical Medicine2018-08-202018-08-202006-04-11Journal of Pharmaceutical and Biomedical Analysis. Vol.41, No.1 (2006), 213-218073170852-s2.0-33645078879https://repository.li.mahidol.ac.th/handle/20.500.14594/23169A sensitive and specific bioanalytical method for determination of piperaquine in urine by automated solid-phase extraction (SPE) and liquid chromatography (LC) has been developed and validated. Buffered urine samples (containing internal standard) were loaded onto mixed phase (cation-exchange and octylsilica) SPE columns using an ASPEC XL SPE robot. Chromatographic separation was achieved on a Chromolith Performance RP-18e (100 mm × 4.6 mm I.D.) LC column with phosphate buffer (pH 2.5; 0.1 mol/L)-acetonitrile (92:8, v/v). Piperaquine was analysed at a flow rate of 3 mL/min with UV detection at 347 nm. A linear regression model on log-log transformed data was used for quantification. Within-day precision for piperaquine was 1.3% at 5000 ng/mL and 6.6% at 50 ng/mL. Between-day precision for piperaquine was 3.7% at 5000 ng/mL and 7.2% at 50 ng/mL. Total-assay precision for piperaquine over 4 days using five replicates each day (n = 20) was 4.0%, 5.2% and 9.8% at 5000, 500 and 50 ng/mL, respectively. The lower limit of quantification (LLOQ) was set to 3 ng/mL using 1 mL of urine, which could be lowered to 0.33 ng/mL when using 9 mL of urine and an increased injection volume. © 2005 Elsevier B.V. All rights reserved.Mahidol UniversityChemistryPharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1016/j.jpba.2005.10.027