Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560847 | Talanta | 2005 | 5 Pages |
Abstract
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 lâ1 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 hâ1 and the relative standard deviation (R.S.D.) was â¤2% for sample solution containing 150 mg lâ1 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.
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
P.R.S. Ribeiro, J.A. Gomes Neto, L. Pezza, H.R. Pezza,