Uv Spectrophotrometry And Chemometrics Methods For Simultaneous Determinations Of Riboflavin (vb2), Thiamine (vb1), Pyridoxine (vb6) And Nicotinamide (vpp) [aplicação De Métodos De Calibração Multivariada Para A Determinação Simultânea De Riboflavina (vb2), Tiamina (vb1), Piridoxina (vb6) E Nicotinamida (vpp)]

In this work, the artificial neural networks (ANN) and partial least squares (PLS) regression were applied to UV spectral data for quantitative determination of thiamin hydrochloride (VB1), riboflavin phosphate (VB2), pyridoxine hydrochloride (VB6) and nicotinamide (VPP) in pharmaceutical samples. For calibration purposes, commercial samples in 0.2 mol L-1 acetate buffer (pH 4.0) were employed as standards. The concentration ranges used in the calibration step were: 0.1 - 7.5 mg L-1 for VB1, 0.1 - 3.0 mg L -1 for VB2, 0.1 - 3.0 mg L-1 for VB6 and 0.4 - 30.0 mg L-1 for VPP. From the results it is possible to verify that both methods can be successfully applied for these determinations. The similar error values were obtained by using neural network or PLS methods. The proposed methodology is simple, rapid and can be easily used in quality control laboratories.30716381643(1984) Kirk-Othmer Encyclopedia of chemical technology, p. 24. , A Wiley-Interscience publication, John Wiley & Sons: New YorkRizollo, A., Polesello, S., (1992) J. Chromatogr, 624, p. 103Hollman, P.C.H., Slanger, J.H., Wagstafe, P.J., Faured, U., Southgate, A.A.T., Finglas, P.M., (1993) Analyst, 118, p. 481Agostini, T.S., Godoy, H.T., (1997) J. High Resol. Chromatogr, 20, p. 245Verma, K.K., Jain, A., Sahasrabuddhey, B., Gupta, K., Mishira, S., (1996) J. AOCS, 79, p. 1236Wu, H., Oguma, K., Yu, R.Q., (1994) Anal. Sci, 10, p. 875Wang, J., Han, J., Su, B., Lin, C., Wamg, N., Hu, J., (1998) Anal.Sci, 14, p. 965Lopes-de-Alba, P.L., Lopes-Martinez, L., Cerda, V., Amador- Hernández, J., (2006) J. Braz. Chem. Soc, 17, p. 715Abeásturi, F.J., Jiménez, I., Arias, J.J., Jiménez, F., (2002) Anal. Lett, 35, p. 1677Hernández, S.R., Ribeiro, G.G., Goicoechea, H.C., (2003) Talanta, 61, p. 743Ferreira, M.M.C., Antunes, A.M., Melgo, M.S., Volpe, P.L.O., (1999) Quim. Nova, 22, p. 724Martens, H., Naes, T., (1989) Multivariate Calibration, , John Wiley & Sons: New YorkWise, B.M., Gallagher, N.B., (1998) PLS-Toolbox 2.1 for use with Matlab, , EigenVector Research Inc: MansonZampronio, C.G., Rohweder, J.J.R., Poppi, R.J., (2002) Chemom. Intell. Lab. Syst, 62, p. 17Despagne, F., Massart, D.L., (1998) Analyst, 123, pp. 157RDemuth, H., Beale, M., (1998) Neural Network toolbox for use with Matlab, , EigenVector Research Inc: Manso

Square Wave Voltammetric Simultaneous Determination Of Nadh And Ascorbic Acid Using Glassy Carbon Electrode And Multivariate Calibration [determinação Simultânea De Nadh E ácido Ascórbico Usando Voltametria De Onda Quadrada Com Eletrodo De Carbono Vítreo E Calibração Multivariada]

In this work, the partial least squares (PLS) method was applied to data obtained by square wave voltammetry for simultaneous determination of ascorbic acid and the b-nicotinamide adenine dinucleotide co-factor (NADH) in synthetic mixtures. The voltammetric curves were obtained in 0.2 mol L- 1phosphate buffer (pH 8.0). From the results it is possible to verify that the PLS method was able to determine these compounds simultaneously in the choose conditions. The results achieved for these determination provided a maximum value for the relative error of 1.7% for NADH and 2.1% for ascorbic acid. The proposed methodology is simple and further studies can make it useful for in vivo analysis.3045158Murthy, A.S.N., Sharma, J., (1998) Talanta, 45, p. 951Tanaka, K., Ikeda, S., Oyama, N., Tokuda, K., Tohsaka, (1993) Analytical Sciences, 9, p. 783Eisenberg, E.J., Cundy, K.C., (1991) Anal.Chem., 63, p. 845Milczarek, G., Ciszewski, A., (2001) Electroanalysis, 13, p. 164Nowall, W.B., Kuhr, W.G., (1995) Anal. Chem., 67, p. 3583Rao, T.N., Yagi, I., Miwa, T., Tryk, D.A., Fujishima, A., (1999) Anal. Chem., 71, p. 2506Martens, H., Naes, T., (1989) Multivariate Calibration, , John Wiley & Sons, New YorkWise, B.M., Gallagher, N.B., (1998) PLS-Toolbox 2.1 for Use with Matlab, , EigenVector Research Inc, W.A Manso

Optimization Of Saponin Extraction Conditions From Ampelozizyphus Amazonicus By Using Experimental Design And Surface Response Methodology [otimização Das Condições De Extração De Saponinas Em Ampelozizyphus Amazonicus Usando Planejamento Experimental E Metodologia De Superfície De Resposta]

METHODOLOGY. This works describes the use of experimental design and surface response methodology for optimization of saponin extraction from Ampelozizyphus amazonicus. For this purpose, a method employing extraction based on maceration assisted by ultrasound technique was utilized. The following factors were studied: extraction length of time and solvent composition. The total saponin was determined by using a gravimetric method and the results expressed by their relative proportion to total crude extract. For the specific condition, 60% hydro-alcoholic solution and 18 minutes extraction length of time has shown the best results. This method can be useful for extraction of substances with biological importance.34916291633Oleszek, W.A., (2002) J. Chromatogr. A, 967, p. 147Simões, C.M.O., Schenkel, E.P., Gosmann, G., Palazzo De Mello, J.C., Ment, L.A., Petrovick, P., (1999) Farmacognosia: Da Planta ao Medicamento, , 1 a ed., Editora UFRGS/Editora UFSC, Porto Alegre - FlorianópolisPrado Martins, E.L., Brandão, M.G.L., (2006) Rev. Bras. Farmacogn., 16, p. 224Vigo, C.L.S., Narita, E., Marques, L.C., (2004) Rev. Bras. Farmacogn., 14, p. 137Sparg, S.G., Light, M.E., Van Staden, J., (2004) J. Ethnopharmacol., 94, p. 219Guterres, S.B., (2005) Dissertação de Mestrado, , Universidade de São Paulo, BrasilJacnezo, Z., Janson, P.E., Sendra, J., (1987) Planta Med., 53, p. 52Diniz, L.R.L., Santana, P.C., Ribeiro, A.P.A.F., Portella, V.J., Pacheco, L.F., Meyer, N.B., Cesar, I.C., Viera, M.A.R., (2009) J. Ethnopharmacol., 123, p. 275Andrade-Neto, V.F., Brandão, M.G.L., Nogueira, F., Rosario, V., Krettli, A.U., (2008) Int. J. Parasitol., 38, p. 1505Brandão, M.G.L., Lacailledubois, M.A., Teixeira, M.A., Krettli, A.U., Wagner, H., (1993) Phytochemistry, 34, p. 1123Chung, H., Ji, X.M., Canning, C., Sun, S., Zhou, K.Q., (2010) J. Agric. Food Chem., 58, p. 4508Korn, M., De Andrade, M.V.A.S., Borges, S.S., (2003) Revista Analytica, 2, p. 34Lin, L., Wu, J., Ho, K., Qi, S., (2001) Ultrasound in Med & Biol., 8, p. 1147Wu, J., Lin, L., Chau, F., (2001) Ultrason. Sonochem., 8, p. 347Box, G.E.P., Hunter, J.S., Hunter, H.G., (1978) Statistics for Experimenters, , John Wiley: New YorkBarros Neto, B., Scarmínio, I.S., Bruns, R.E., (1995) Planejamento e Otimização de Experimentos, , 2a.ed., Educamp: CampinasTeófilo, R.F., Ferreira, M.M.C., (2006) Quim. Nova, 29, p. 338Namba, T., Yoshizaki, M., Tomomori, T., (1974) Planta Med., 25, p. 28Noldin, V.F., Cechinel Filho, V., Monache, F.D., Benassi, J.C., Christmann, I.L., Pedrosa, R.C., Yunes, R.A., (2003) Quim. Nova, 26, p. 331Kwon, J., Bélanger, J.M.R., Paré, J.R., (2003) J. Agric. Food Chem., 51, p. 180