Acetylsalicylic Acid Determination In Pharmaceutical Samples By Fia-potentiometry Using A Salicylate-sensitive Tubular Electrode With An Ethylene-vinyl Acetate Membrane

The construction of a salicylate-sensitive tubular potentiometric electrode for flow injection analysis (FIA) is described, in which an ethylene-vinyl acetate (EVA) copolymeric membrane, 40% in vinyl acetate, is applied directly onto a conducting support consisting of a mixture of an epoxy resin and graphite. The tubular salicylate ion-selective electrode is based on tricaprylyl-trimethyl-ammonium (Aliquat(TM)) salicylate as the ion-exchanger, supported on the polymeric matrix without plasticizer solvent. The tubular electrode showed a response of 58.3mV per concentration decade within the 5.0x10-3-5.0x10-1moll-1 salicylate range in 0.1moll-1 Tris-HCl buffer (pH=7.5). Iodide is the main analytical interferent; the electrode response time was 5s at 25°C. Determinations of acetylsalicylic acid in tablet samples by the proposed method exhibit relative errors lower than 2%, when compared with a spectrophotometric method. The useful lifetime of the tubular sensor is longer than 3 months. Copyright (C) 1998 Elsevier Science B.V.3661-3103109Moore, T.J., Joseph, M.J., Allen, B.W., Coury L.A., Jr., (1995) Anal. Chem., 67, p. 1896Thiessen, J.J., (1992) Acetylsalicylic Acid: New Uses for An Old Drug, pp. 49-61. , in: H.J.M. Barnett, J. Hirsh, J.F. Mustard (Eds.), Raven Press, New York, N.YKibbey, C.E., Park, S.B., Deawyler, G., Meyerhoff, M.E., (1992) J. Electroanal. Chem., 335, p. 135Creager, S.E., Lawrence, K.D., Tibbets, C.R., (1995) J. Chem. Educ., 72 (3), p. 274Li, J.Z., Pang, X.Y., Gao De, Yu, R.Q., (1995) Talanta, 42, p. 1775Liu, D., Chen, W.C., Shen, G.L., Yu, R.Q., (1996) Analyst, 121, p. 1495Hutchins, R.S., Bansal, P., Molina, P., Alajarín, M., Vidal, A., Bachas, L.G., (1997) Anal. Chem., 69, p. 1273Lima, J.L.F.C., Montenegro, M.C.B.M., Silva, A.M.R., (1990) J. Flow Injection Anal., 7 (1), p. 19Katsu, T., Mori, Y., (1996) Talanta, 43, p. 755Longenecker, R.W., Trafton, J.E., Edwards, R.B., (1984) Clin. Chem., 30 (8), p. 1369You, K.S., Bittikofer, J.A., (1984) Clin. Chem., 30 (9), p. 1549Chamarro, J.A., Bartrolí, J., Jun, S., Lima, J.L.F.C., Montenegro, M.C.B.M., (1993) Analyst, 118 (12), p. 1527Rover L., Jr., Neto, G.O., Lima, J.L.F.C., Montenegro, M.C.B.M., (1996) Quím. Nova, 19 (5), p. 549Alçada, M.N.M.P., Lima, J.L.F.C., Montenegro, M.C.B.M., (1992) J. Pharm. Biomed. Anal., 1 (10-12), p. 757Jun, S., Lima, J.L.F.C., Montenegro, M.C.B.M., (1994) J. Trace Elem. Electrolytes Health Dis., 8, p. 93Jamal, A.E., Bouklouze, A.A., Patriarche, G.J., Christian, G.D., (1991) Talanta, 38 (8), p. 929Thomas, J.D.R., (1986) Anal. Chim. Acta, 180, p. 289Fiedler, U., Ruzicka, J., (1973) Anal. Chim. Acta, 67, p. 179Bailey, P.L., (1980) Analysis with Ion-selective Electrodes, pp. 2-3. , in: J.J. Bouma (Ed.), 2nd ed., London, 45-53Valcárcel, M., Castro, M.D.L., (1984) Análisis Por Inyección en Flujo, pp. 47-52. , San Pablo Press, CordobaUmezawa, Y., Umezawa, K., Sato, H., (1995) Pure Appl. Chem., 67, p. 507Aubeck, R., Bräuchle, C., Hampp, N., (1991) Analyst, 116, p. 811Trinder, P., (1954) Biochem. J., 57, p. 301McDonald, R.P., (1965) Standard Methods of Clinical Chemistry, 5, p. 237. , Academic Press, New York, N.Y(1980), p. 733. , British Pharmacopoeia, Her Majesty's Stationary Office, Londo