Problems of Forensic Sciences 2005 Vol. 61 (LXI) 64-71
METHODOLOGY OF STEREOSELECTIVE DETERMINATION OF VERAPAMIL IN SERUM
Jolanta WILIMOWSKA1, Wojciech PIEKOSZEWSKI2, Ewa FLOREK3
1Department of Analytical Toxicology and Therapeutic Drug Monitoring, Collegium Medicum, Jagiellonian University, Krakow
2Institute of Forensic Research, Krakow
3Laboratory of Environmental Research, Department of Toxicology, University of Medical Sciences, Poznań
Streszczenie
Verapamil was extracted from serum by liquid-liquid extraction (pH 9) with hexane. For the analysis of extracts, high performance liquid chromatography with fluorescence detector was used (excitation at 230 nm, emission at 312 nm). Oxprenolol was used as an internal standard. The stereoselective separation of verapamil was carried out on a ChiraDex column. More than 60% of the enantiomers of verapamil were separated from each other using a mobile phase of 5% triethylamine acetate – methanol (80:20, v/v). The flow rate of the mobile phase was 1 ml/min. The method developed was characterised by linearity of concentration ranging from 2.5 to 200 ng/ml for each of the verapamil enantiomers. The enantiomers were identified at an average retention time of 10.8 min for S(–)-verapamil and 11.7 min for R(+)-verapamil. The limit of detection equalled 0.7 ng/ml and 0.6 ng/ml for S(–)- and R(+)-verapamil respectively. The limit of quantitation was 2.5 for both verapamil isomers. Intra and inter-day precision ranged from 3.1–8.5%. This method was applied to analysis of verapamil in one case of fatal poisoning, one acutely poisoned patient and in three pregnant women who had received verapamil for therapeutic purposes.
Słowa kluczowe
Stereoselectivity; Chiral chromatography; Verapamil.