title: Determination of alendronate in human urine as 9-fluorenylmethyl derivative by high-performance liquid chromatography.
abstract: A high-performance liquid chromatographic method for the quantitation of alendronate as the 9-fluorenylmethyl derivative (FMOC) in human urine is presented. The sample preparation involved coprecipitation with calcium phosphate, separation on diethylamine (DEA) solid-phase extraction (SPE) cartridge and derivatization with 9-fluorenylmethyl chloroformate in citrate buffer pH 11.9. Liquid chromatography was performed on an octadecylsilica column (150 x 4.6 mm, 3 microm particles); a gradient method with starting mobile phase acetonitrile-methanol-citrate/pyrophosphate buffer (20:15:65 v/v) was employed. The total run time was 21 min. The fluorimetric detector was operated at the following wavelengths: 260 nm (excitation) and 310 nm (emission). Pamdronate was used as the internal standard. The limit of quantitation was 3.5 ng/ml using 5 ml of urine. Within-day and between-day precision expressed by relative standard deviation was less than 8% and inaccuracy did not exceed 9%. The assay was applied to the analysis of samples from a pharmacokinetic study.
authors.affiliation: Pharmakl SRO, Prague, Czech Republic. pharmakl@mbox.vol.cz
authors.forename: P
authors.initials: P
authors.lastname: Ptácek
authors.forename: J
authors.initials: J
authors.lastname: Klíma
authors.forename: J
authors.initials: J
authors.lastname: Macek
mesh_terms: D019386:Alendronate / Q000737:chemistry / Q000652:urine*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005449:Fluorenes / Q000737:chemistry*; D006801:Humans; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
chemical_list: D005449:Fluorenes; C054007:1-(9-fluorenyl)methyl chloroformate; D019386:Alendronate