Abstract
A photometric flow titration based on the redox reaction between KMnO 4 and minoxidil isdescribed. The best titration results were observed at 3.20 x 10 -4 mol L -1 KMnO 4 and 1.00 x 10 -3 mol L -1
minoxidil, using the minoxidil solutions as titrant. The flow rate was fixed at 17 mL min -1 and the titrant
was added to the system in aliquots of 500 μL, the color changes were monitored at 550 nm. The method
was applied to commercial samples and compared with the results from a chromatographic procedure.
Recoveries from 97.6 to 102.8 % were observed depending on the sample. Comparison with the
chromatographic procedure reveled relative errors of 3.5 - 4.0 %.
References
S. S. Budavari, M.J. O’Neil, A. Smith, P.E. Heckelman,
J.F. Kinneary, The Merck Index, 13 th , Merck & Company
Incorporated, Whitehouse Station, New Jersey, 2001,
p.
L. Amankwa, L. G. Chatten, S. Pons, Analyst, 108 (1983)
A. R. Medina, M. L. F. Córdova, A. Molina-Díaz, Talanta,
(1999) 277.
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.
W. Misiuk, H. Puzanowska-Tarasiewics, Anal. Lett., 35
(2002) 1163.
A. Zarghi, M. Jenabi, A. J. Ebrahimian, Pharm. Acta Helvet.,
(1998) 163.
S. Fanali, M.Cristalli.; P. Catellani, J. Chromatogr. A, 405
(1987) 385.
G. Carrum, D.R. Abernethy, M.S.C.E. Wright, J.
Chromatogr. B, 381 (1986) 127.
A. Zarghi, A. Shafaati, S.M. Foroutan, A. Hoddam, J.
Pharm. Biomed. Anal., 36 (2004) 377.
D. A. Skoog, D. M. West, F. J. Hooler, Fundamentals of
Analytical Chemistry, 7 th edn, Saunders College Publishing, Phila-
delphia, 1996, p.581.
Z. Liang, C. Bonneville, T. Senez, T. Henderson, J. Pharm.
Biomed. Anal., 28 (2002) 245.
P. J. Fletcher, J. F. Van-Staden, Anal. Chimica Acta, 485
(2003) 187.
R. S. Honorato, E. A. G. Zagatto, R. A. C. Lima, M. C.
U. Araújo, Anal. Chim. Acta, 416 (2000) 231.
T. Masadome, Talanta, 59 (2003) 659.
L. Sommer, Analytical absorption spectrophotometry in
the visible and ultraviolet – The Principles, Elsevier, Budapeste,
, p.311.
G.D. Christian, Analytical Chemistry, 5 th edn, Wiley &
Sons, New York, 1994, p.365.
D. C. Harris, Análise Química Quantitativa, 5 th edn, LTC,
Rio de Janeiro, 2001, p.130.
R. M. Dyson, P. Jandanklang, M. Maeder, C. J. Mason,
A. Whitson, Polyhedron, 18 (1999) 3227.

This work is licensed under a Creative Commons Attribution 4.0 International License.
Copyright (c) 2018 Eclética Química Journal