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This paper describes the construction of an electrode of the second kind, Pt |Hg|Hg2(Salic)2|Graphite, sensitive to salicylate. This electrode responds to the salicylate ion with a sensivity of 58.66 mV/decade over the range 6.0 〈10-4 ‐1.0〈10-1 mol/l at pH 6.0 and an ionic strength of 0.500 ‐3.00 mol/l, adjusted with NaClO4. The electrode is easily constructed, shows a fast response time, is low in cost, has excellent response stability, and has a lifetime greater than 18 months, which is much longer than those reported earlier for other systems. The influence of 10 different carboxylate and inorganic anions on the electrode response showed that there was negligible interference by most of these ions. It was used to determine aspirin in tablets (after hydrolysis of acetylsalicylic acid to salicylate) by means of the standard additions method. The results obtained using this electrode for aspirin determination, in three different samples of antithermic drugs, compared favorably with the results given by the British Pharmacopoeia method.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:49:06Z No. of bitstreams: 0 Made available in DSpace on 2013-08-22T18:49:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-01-01 Made available in DSpace on 2013-09-30T19:39:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-01-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:21:03Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:21:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-01-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação para o Desenvolvimento da UNESP (FUNDUNESP) Este trabalho descreve a construção de um eletrodo de segunda espécie, Pt|Hg|Hg2Ox|Grafite, sensível ao íon oxalato (Ox). O eletrodo é construído facilmente, apresenta um rápido tempo de resposta, é de baixo custo, e tem um tempo de vida útil superior a 12 meses. O potencial molal padrão do eletrodo a 25ºC é 417,3 ± 1,0 mV. A validação do eletrodo foi conseguida pela determinação do produto de solubilidade,T K PS (I=0), do Hg2C2O4 (T K PS = (2,53 ± 0,21) x 10-13 mol². L-2). Uma característica favorável consiste no fato de que o eletrodo pode ser utilizado para determinar a concentração de íons oxalato livres em sistemas complexos de íons metálicos. This paper describes the construction of an electrode of the second kind, Pt|Hg|Hg2Ox|Grafite, sensitive to oxalate ion (Ox). The electrode is easily constructed, shows a fast response time, is low in cost, and has a lifetime greater than 12 months. The standard molal potential of the electrode at 25ºC is (417.3 ± 1,0) mV. The electrode validation has been carried out by determining the solubility product, T K PS (I=0), of Hg2C2O4 (T K PS = (2.53 ± 0.21) x 10-13 mol². L-2). A favorable feature lies in the fact that the electrode can be utilized to determine the concentration of free oxalate ions in complex systems of metallic ions. Universidade Estadual Paulista Instituto de Química Universidade Estadual Paulista Instituto de Química