Yahdiana Harahap
Universitas Indonesia, Indonesia
Title: Analysis of Valproic Acid with Dried Blood Spot Method by Ultra Performance Liquid Chromatography – Mass Spectrometer
Biography
Biography: Yahdiana Harahap
Abstract
Valproic Acid is an anticonvulsant, which can be used to treat all types of epilepsy and has also been developed to be used as an adjuvant therapy for bipolar disorder. Valproic acid has narrow therapy index therefore it needs therapeutic drug monitoring with dried blood spot method which is simple, easy, and accurate. The objective of this research is to obtain optimum and validated method of Valproic acid in whole blood as Dried Blood Spot (DBS) using Ultra Performance Liquid Chromatography – tandem mass spectrometry (UPLC-MS/MS). The quality control and calibration samples were obtained by pipetting as much as 20 µL blood sample onto CAMAG DBS paper and then left to dry at room temperature for 1 hour. Then the disc was transferred into micro tube and added 200 µL extraction solution (acetonitrile – methanol mixed solution (1:3) containing benzoic acid as internal standard with concentration of 1000 µg/mL. Chromatographic separation was conducted using Waters Acquity UPLC Class BEH C18 1.7 µm (2.1 x 100 mm) with mobile phase of 0.1% acetic acid - acetonitrile (40-60) under isocratic elution and flow rate of 0.4 mL/minute. Mass detection was performed with an Electrospray Ionization (ESI) source at negative ion mode in the Multiple Reaction Monitoring. Detection of Valproic acid was performed at m/z 142.95 > 142.95 value; and benzoic acid was at m/z 121.1 > 77.1. This method was linear on range concentration of 0.5 – 100 µg/mL with r > 0.9991. Dried Blood Spot sample was stable for minimum of 16 days in room temperature and the validated analysis method was applied on one healthy subject.