Simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceuticals using a carbon paste electrode modified with lead dioxide immobilized in a polyester resin

• Autor(a) principal: Melo,Hélio Corrêa de
• Data de Publicação: 2007
• Outros Autores: Seleghim,Ana Paula D., Polito,Wagner Luiz, Fatibello-Filho,Orlando, Vieira,Iolanda C.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532007000400019
• topic: L-dopa; carbidopa; differential pulse voltammetry (DPV); carbon paste electrode modified with lead dioxide

A carbon paste electrode modified with lead dioxide immobilized in a polyester resin has been developed for simultaneous differential pulse voltammetric determination of L-dopa and carbidopa in pharmaceutical formulations. The analytical curves were linear in the concentration ranges from 2.6 <FONT FACE=Symbol>´</FONT> 10-4 to 1.2 <FONT FACE=Symbol>´</FONT> 10-3 mol L-1 and from 3.2 <FONT FACE=Symbol>´</FONT> 10-5 to 1.5 <FONT FACE=Symbol>´</FONT> 10-4 mol L-1 for L-dopa and carbidopa, respectively. The detection limits were 2.5 <FONT FACE=Symbol>´</FONT> 10-5 mol L-1 and 3.7 <FONT FACE=Symbol>´</FONT> 10-6 mol L-1 for L-dopa and carbidopa, respectively and recoveries of L-dopa and carbidopa from two samples ranged from 98.1 to 103% of the added amount. The relative standard deviations were lower than 2.5% for 1.2 <FONT FACE=Symbol>´</FONT> 10-4 and 1.2 <FONT FACE=Symbol>´</FONT> 10-3 mol L-1 of these catecholamines solutions and the results obtained for L-dopa and carbidopa in pharmaceutical formulations using the proposed voltammetric procedure are in close agreement with the labeled values and/or those obtained using an enzymatic method at the 95% confidence level.