Flow-injection spectrophotometric determination of methyldopa in pharmaceutical formulations
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Data
2005-07-15
Autores
Ribeiro, PRS
Neto, JAG
Pezza, Leonardo [UNESP]
Pezza, Helena Redigolo [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Elsevier B.V.
Resumo
A flow-injection spectrophotometric procedure is proposed for methyldopa determination in pharmaceutical preparations. The determination is based on formation of a yellow product (measured at 410 nm) after complexation of methyldopa with molybdate. Under optimal conditions, Beer's law is obeyed in a concentration range of 50-200 mg l(-1) methyldopa. Typical correlation between absorbance and analyte concentration was 0.9999. Usual excipients used as additives in pharmaceuticals do not interfere with the proposed method. The analytical frequency was 210 h(-1) and the relative standard deviation (R.S.D.) was <= 2% for sample solution containing 150 mg l(-1) methyldopa (n = 11). The analytical results obtained in commercial formulations by applying the proposed FIA method were in good agreement with labeled values and those obtained by the Brazilian Pharmacopoeia procedure at 95% confidence level. (C) 2005 Elsevier B.V. All rights reserved.
Descrição
Palavras-chave
flow-injection analysis, methyldopa, molybdate, pharmaceutical formulations
Como citar
Talanta. Amsterdam: Elsevier B.V., v. 67, n. 1, p. 240-244, 2005.