Keywords
titration
potenciometry
How to Cite
Abstract
A potentiometric titration method for the determination of minoxidil based on its redox reaction with K2Cr2O7 is described. The best results were observed using 1.00 x 10-3 mol L-1 K2Cr2O7 and 1.00 x 10-2 mol L-1 minoxidil solutions, and the minoxidil as titrant in 2.00 mol L-1 H2SO4 medium. The method was applied to commercial samples and compared with the results from a chromatographic procedure. Recoveries from 97.4 to 98.7 % were observed depending on the sample. Comparison with the chromatographic procedure reveled agreement within 90% confidence level.References
S. S. Budavari, M.J. O’Neil, A. Smith, P.E. Heckelman, J.F. Kinneary, The Merck Index, 13th , erck & Company Incorporated, Whitehouse Station, New Jersey, 2001, 6229p.
Amankwa, L.; Chatten, L.G.; Pons, S.; “Electrochemical studies on minoxidil and determination in tablets by differential-pulse polarography” Analyst, 108: 1221, 1983.
Ruiz-Medina, A.; Fernandez-de Cordova, M.L.; Molina-Diaz, A.; “Integrated flow injection-solid phase spectrophotometric determination of minoxidil”. Talanta, 50 (2): 277, 1999.
J. H. Han, O. S. Kwon, J. H. Chung, K. H. Cho, H. C. Eun, K. H. Kim, J. Dermatol. Sci., 34 (2004) 91.
W. Z. Zhong, P. E. Sanders, M. J. Hauer, J. J. Vrbanae,
J.Chromatogr. B, 705 (1998) 39.
W. Z. Zhong, J. Pharm. Biomed. Anal., 16 (1998) 1179.
Sousa, R. A.; Semaan, F.S.; Fragali, J.A.B.; Cavalheiro
E.T.G.; “Fast Determination of Minoxidil by Photometric Flow Titration”. Eclética Química, 30 (3): 79, 2005.
Sousa, R. A.; Calheiro E.T.G.; “Determinação de minoxidil
em formulações farmacêuticas usando permanganometria”.
Eclética Química, submitted.
Zarghi, A.; Jenabi, M.; Ebrahimian, A. J. “ HPLC determination of the tretonoin-minoxidil solution” Pharm. Acta
Helvet., 73: 163, 1998.
Fanali, S.; Cristalli, M.; Catellani, P.; “Determination of
minoxidil in pharmaceutical forms by capillary isotachophoresis”. J. Chromatogr. A, 405: 385, 1987.
G. Carrum, D.R. Abernethy, M.S.C.E. Wright, J. Chromatogr. B, 381 (1986) 127.
Zarghi, A.; Shafaati, A.; Foroutan, S.M.; Khoddam, A.;
“Rapid determination of minoxidil in human plasma using
ion-pair HPLC”. J. Pharm. Biomed. Anal, 36: 377, 2004.
Skoog, D.A.; Holler, F.J.; Nieman, T.A.; Princípios de
Análise Instrumental, quinta edição, 548, Artmed editora S.A,
Jeffery, G.H.; Bassett, J.; Mendham, J.; Denney, R.C.;
Vogel. Análise Química Quantitativa, quinta edição, 436, LTC, 1992.
Jeffery, G.H.; Bassett, J.; Mendham, J.; Denney, R.C.;
Vogel. Análise Química Quantitativa; quinta edição; 268; LTC Ltda. 1992
Skoog, D.A.; Holler, F.J.; Nieman, T.A.; Princípios de
Análise Instrumental, quinta edição, 548, Artmed editora S.A,
Gran, G.; ”Determination of the equivalent point in potentiometric titrations”. Acta Chemica Scandinavica, 4: 559,
Harris, D.C. Análise Química Quantitativa, quinta edição,
, LTC – Livros técnicos e Científicos Editora AS, 2001. 5: 39, 1998.
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