GC and MS properties of β-blockers as tert-butyldimethylsilyl derivatives and as ethoxycarbonyl/trimethylsilyl derivatives.

Abstract

Fourteen β-blockers in pre-dried free base forms were simultaneously converted into tert-butyldimethylsilyl (TBDMS) derivatives in one-step. As a different approach, β-blockers were directly transformed into N-ethoxycarbonyl (EOC) derivatives in aqueous solution, followed by extraction and trimethylsilyl (TMS) derivatization. The retention index sets measured by DB-5 and DB-17 dual-column GC were characteristic for each β-blocker as TBDMS- and EOC/TMS derivatives. Their characteristic fragmentation patterns obtained by GC-MS facilitated easier peak identification of each β-blocker. The overall EOC/TMS method for assays of 14 β-blockers in aqueous solution was linear with acceptable precision and accuracy. © 2006 Friedr. Vieweg & Sohn Verlag/GWV Fachverlage GmbH.