HPTLC and MS for Separation andIdentification of Some b-Blockers in Urine

Abstract

Using high performance thin layer chromatography (HPTLC)coupled with mass-spectrometry (MS) we separated and identified someb-blocker drugs i.e., labetalol and metoprolol in urine. The separationwas performed on silica gel 60 HPTLC (Merck) with toluene-ethyl acetateacetone-NH4OH (25 %), 10 + 20 + 20 + 1 (v/v) as mobile phase. Identificationof the components was performed in ultraviolet light (UV) andby mass-spectrometry. After one dose of drug (metoprolol or labetolol)intake, urine samples were taken from which the eliminated drug isextracted with ethyl acetate. After processing the extract was separated andidentified by HPTLC and MS. Quantitative measurement were performedby photodensitometry of the developed plates at 265 nm by using a Camagphotodensitometer.