Method of Preparing Blood Samples on Solid Sorbents for Quantitative Determination of Valproic Acid with Gas Chromatography and Mass Spectrometric Detection

Purpose. Development of technique of preparation of biological objects for detection and
quantitative determination of valproic acid in blood with gas chromatography and mass
spectrometric detection (GC/MS).
Materials and methods. Blood serum of patients aged 25–30 years; valproic acid (Valproic acid,
"Sanofi") in the form of tablets 500 mg, chloroform, ethyl acetate, the systems for extraction: EXtrelut®
(Merck, Germany), EVIDEX-BOX 50% 3 ml tubes, 300 mg (Agilent, USA); Agilent 6890N Network GC
System gas chromatograph, Agilent 5975C VL VSD mass-selective detector (Agilent, USA).
Results. The method is proposed for preparing blood samples using traditional liquid-liquid
extraction, solid-liquid extraction based on natural diatomaceous limestone sorbent (exclusive
chromatography), and solid-phase extraction based on the universal sorbent selikogel C18, for
determination of valproic acid based on gas chromatography with mass-selective detection in the
SIM monitoring mode.
Conclusion. During the research, the effectiveness of application of various sorbents used in
liquid-liquid, solid-phase and solid-liquid extraction for isolation of valproic acid from biological
material (blood) for further quantitative determination with gas-liquid chromatography – mass
spectrometry was established. The method for quantitative determination of VPA in the mode of
selective monitoring, using gas chromatography with mass-selective detection, was developed,
and the optimal conditions for preparation of blood samples and eluents for isolation of valproic
acid from biological objects were established.