Stereoselective determination of pyridoglutethimide enantiomers in serum with a chiral cellulose-based high-performance liquid chromatographic column using solid phase extraction and UV detection.
A sensitive method for the separation and determination of R(+)- and S(-) enantiomers of pyridoglutehimide in serum by high performance liquid chromatography (HPLC) with UV detection was developed. The assay involves the use of a solid-phase extraction for serum sample clean-up prior to HPLC analysis using a C18 Bond-Elute column. Chromatographic resolution of the enantiomers was performed on a reversed-phase cellulose-based chiral column (Chiralcel OD-R, 250 x 4.6 mm I.D.) under isocratic conditions using a mobile phase of 25:75 v/v acetonitrile-0.3 M aqueous sodium perchlorate (pH 6.2 adjusted with perchloric acid) at a flow rate of 0.8 ml/min. Recoveries for R(+)- and S(-)-pyridoglutethimide enantiomers were in the range 86-91% at 300-900 ng/ml level. Intra-day and inter-day precision calculated as %R.S.D. were in the ranges of 2.9-3.9 and 1.5-4.7% for both enantiomers, respectively. Intra-day and inter-day accuracies calculated as percentage error were in the ranges of 1.9-3.3 and 1.5-3.9% for both enantiomers, respectively. Linear calibration curves in the concentration ranges of 100-1500 ng/ml for each enantiomer show correlation coefficient (r) of more than 0.9995. The limit of quantification (LOQ) of each enantiomer was 100 ng/ml using 1 ml of serum. The detection limit (LOD) for each enantiomer in serum using a UV detection set at 257 nm was 50 ng/ml (S/N = 2).
Hefnawy
M M
MM
Department of Analytical Chemistry, Faculty of Pharmacy, University of Mansoura, Mansoura 35516, Egypt. mhefnawy@mans.edu.eg
D000616:Aminoglutethimide / Q000031:analogs & derivatives* / Q000097:blood* / Q000737:chemistry; D000818:Animals; D002138:Calibration; D002417:Cattle; D002482:Cellulose; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism
D000616:Aminoglutethimide; C049837:rogletimide; D002482:Cellulose