Determinação espectrofotométrica de ácido glicólico com ácido cromotrópico assistida por forno de microondas
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Abstract
No presente trabalho foi desenvolvido um método espectrofotométrico rápido, simples e seletivo para análise de ácido glicólico, o qual baseia-se na reação colorida entre o formaldeído liberado pelo ácido glicólico e o ácido cromotrópico, quando a reação é realizada em meio de ácido fosfórico concentrado e com aquecimento, utilizando para isso irradiação em forno de microondas doméstico para acelerar a reação. O composto corado formado apresenta um máximo de absorção a 570 nm, sendo necessários apenas 30 segundos de irradiação em forno de microondas (1100 Watts) para que a reação seja completa. A Lei de Beer é obedecida no intervalo de 0-2208 mg L-1. O método proposto foi aplicado na análise de amostras comerciais de ácido glicólico utilizadas em farmácias de manipulação no preparo de medicamentos de combate à acne, fornecendo bons resultados, com recobrimentos entre 97,0-101,4% e desvio padrão de 0,2-0,4%.
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References
BUDAVARI, S.; FERTIG, M.N.; STROUMTSOS, L.Y.; WINDHOLZ, M. The Merck index. 9th.ed. Rahway: Merck & Co., 1976. p.583. [ Links ]
CHEN, J.C.P.; CHOU, C.C. Cane sugar handbook, 12th.ed. New York: John Wiley & Sons, 1993. p.33. [ Links ]
FEIGL, F. Spot tests in organic analysis. 7th.ed. New York: Elsevier, 1956. p.434-437. [ Links ]
KIRK, R.E.; OTHMER, D.F. Encyclopedia of chemical technology. New York: The Interscience Encyclopedia, 1951, v.7, p.232-237. [ Links ]
KIRK, R.E.; OTHMER, D.F. Encyclopedia of chemical technology. New Yoirk: Wiley, 1981, v.13, p.92. [ Links ]
LEBOULANGER, C.; SERVE, L.; COMELLAS, L.; JUPIN, H. Determination of glycolic acid released from marine phytoplankton by post-derivatization gas chromatography mass spectrometry. Phytochem.l Anal., v.9, p.5-9, 1998. [ Links ]
NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH. NIOSH manual of analytical methods (NMAM): method 3500(2)-formaldehyde. 4th.ed. 1994. p.1-5. [ Links ]
OUNGPIPAT, W.; ALEXANDER, P.W. An amperometric bienzyme sensor for glycolic acid determination based on spinach tissue and ferrocene-mediation. Anal. Chim. Acta, v.295, p.37- 46, 1994. [ Links ]
PORTER, W.H.; RUTTER, P.W.; YAO, H.H. Simultaneous determination of ethylene glycol and glycolic acid in serum by GC/MS. Clin. Chem., v.43, p.485, 1997. [ Links ]
SARFATI, S.R.; SZABÓ, P. Quantitative micro-determination of glycolic acid in complex mixtures obtained from periodate oxidation of carbohydrates. Carbohyd. Res., v.12, p.290-292, 1970. [ Links ]
SCALIA, S.; CALLEGARI, R.; VILLANI, S. Determination of glycolic acid in cosmetic products by solid-phase extraction and reversed-phase Ion-pair high-performance liquid chromatography. J. Chromatogr. A, v.795, p.219-225, 1998. [ Links ]
SOUZA, S.R.; VASCONCELLOS, P.C.; CARVALHO, L.R.F. Low molecular weight carboxylic acids in an urban atmosphere: winter measurements in Sao Paulo City, Brazil. Atm. Environ., v.33, p.2563-2574, 1999. [ Links ]
TAKAHASHI, K. A Colorimetric method for quantitative determination of glycolic acid with 2,7-dihydroxynaphthalene. J. Biochem., v.71, p.563-565, 1972. [ Links ]
VICCARO, J.P.; AMBYE, E.L. Colorimetric determination of glycolic acid with b-naphthol. Microchem. J., v.17, p.710, 1972. [ Links ]
VOGEL, A.I. Análise química quantitativa. 5.ed. Rio de Janeiro: Guanabara Koogan, 1992. p.225-226, 241-242, p. 304-305, 1992. [ Links ]
WILLIAMS, H.E. Oxalic-acid and hyperoxaluric syndromes. Kidney Int., v.13, p.410-417, 1978. [ Links ]