Characterization of pharmaceutical drugs by a modified nonaqueous capillary electrophoresis – mass spectrometry method

Abstract

A simple method for the separation and characterization of a group of nine basic compounds, comprising seven tricyclic antidepressant and two bronchodilator drugs, by nonaqueous capillary electrophoresis (NACE) employing ultraviolet and mass spectrometry detection is described. After optimization of the electrophoresis separation conditions, including the compositions of the electrolyte and the organic solvent, a reliable separation of all nine basic analytes was achieved in 80 mM ammonium formate dissolved in a methanol-acetonitrite (80:20 v/v) mixture, having an apparent pH of 8.7. The volatile nonaqueous electrolyte system used with a normal electroosmotic flow polarity also provided an optimal separation condition for the characterization of the analytes by mass spectrometry. When results were compared with reversed-phase gradient and isocratic high-performance liquid chromatography (HPLC) methods, the NACE method provided greater efficiency, achieving baseline resolution for all nine basic compounds in less than 30 min. The NACE method is suitable for use as a routine procedure for the rapid separation and characterization of basic compounds and is a viable alternative to HPLC for the separation of a wide range of pharmaceutical drugs.

Separation and determination of active components inSchisandra chinensis Baill. and its medicinal preparations by non-aqueous capillary electrophoresis

“…More recently, the use of NACE has gained considerable importance in the analysis of pharmaceuticals and more and more applications have been reported Peri-Okonny et al, 2003;Hilder et al, 2002;Sanders and Cunningham, 2002). The advantages of non-aqueous solvents in CE have been discussed from various viewpoints (Riekkola, 2002;Grob and Steiner, 2002;Miller et al, 2000).…”

Nonaqueous capillary electrophoresis in coated capillaries: An interesting alternative for proteomic applications

“…In the presence of some nonaqueous electrolytes, these coated capillaries present an EOF that is not suppressed to low levels as in aqueous media [11,12]. It is important to note that such situation can offer great contributions for bioseparation solutions [13][14][15], since there will be a significant EOF with low analyte -wall interaction.…”

Eletroforese capilar acoplada à espectrometria de massas (CE-MS): vinte anos de desenvolvimento

“…23,24 Os trabalhos pioneiros envolvendo aplicações de CE-MS, utilizando eletrólitos não-aquosos, foram realizados por Tomlinson et al 25 na separação de drogas e metabólitos. Uma das vantagens que estes tipos de eletrólitos oferecem é a formação de um spray estável e compatível com o sistema MS. 26,27 Este fenômeno ocorre principalmente ao se utilizar capilares com revestimento polimérico interno e eletrólitos contendo modificadores orgânicos (como formamida, metanol e acetonitrila), em análises de proteínas e peptídeos. [28][29][30] Outros modos de separação que empregam eletrólitos mais elaborados, como isotacoforese capilar transiente (t-CITP -transient capillary isotacophoresis), focalização isoelétrica capilar (CIEFcapillary isoeletric focusing) e cromatografia eletrocinética micelar (MEKC -micellar electrokinetic chromatography), também podem ser utilizados.…”