title: Liquid-chromatographic analysis for esmolol and its major metabolite in urine.
abstract: We describe a simple, reproducible liquid-chromatographic method for determination of esmolol (a short-acting beta blocker) and its major metabolite in human urine. Esmolol is extracted from urine at a pH of 8.4 into methylene chloride; the more polar metabolite remains in the aqueous phase. We then measure esmolol with a muBondapak C18 column and measure ultraviolet absorbance at 229 nm; the metabolite is analyzed with a Spherisorb phenyl column, with absorbance measured at 280 nm. The average extraction recoveries of esmolol and the metabolite were 95 and 92%, respectively. Standard curves were linear and reproducible for esmolol from 0.025 to 5 mg/L and for the metabolite from 1 to 250 mg/L. Within-day CVs for both compounds were less than 6%.
mesh_terms: D002851:Chromatography, High Pressure Liquid; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D011412:Propanolamines / Q000378:metabolism* / Q000652:urine; D012015:Reference Standards; D013997:Time Factors
chemical_list: D011412:Propanolamines; C036604:esmolol