Construção e avaliação de um eletrodo tubular sensível ao íon hidrogênio como detector em sistemas de análise em fluxo

Martelli, Patrícia Benedini; Reis, Boaventura F.; Zagatto, Elias A.G.; Lima, José Lezama; Lapa, Rui A. S.

doi:10.1590/s0100-40421998000200005

Cited by 4 publications

(3 citation statements)

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“…A review about analytical applications of conducting polymers in potentiometric sensors has been published by Kubota and co-workers. 17 The construction of a hydrogen ion-selective potentiometric electrode based on a tridodecylamine ionophore dispersed in a poly(vinylchloride) (PVC) membrane, 18,19 or poly(1-aminoanthracene) films 20 has been described. In addition, Rodwedder et al 21 and Fatibello and co-workers [22][23][24][25] have shown the use of coated graphite epoxy ion selective electrodes for determinaton of cations using ion-pair formation with tricaprylylmethylammonium cation in a PVC matrix.…”

Section: Potentiometric Sensorsmentioning

confidence: 99%

Electrochemical sensors: a powerful tool in analytical chemistry

Stradiotto¹,

Yamanaka²,

Zanoni³

2003

J. Braz. Chem. Soc.

316

148

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Sensores potenciométricos, amperométricos e condutométricos são sensores eletroquímicos com imensa aplicação nas áreas de meio ambiente, indústria e análises clínicas. O presente trabalho apresenta uma revisão generalizada dos aspectos fundamentais, os desenvolvimento e a contribuição destes sensores na área de química analítica, e reporta alguns aspectos relevantes dos avanços na área de sensores eletroquímicos no Brasil.Potentiometric, amperometric and conductometric electrochemical sensors have found a number of interesting applications in the areas of environmental, industrial, and clinical analyses. This review presents a general overview of the three main types of electrochemical sensors, describing fundamental aspects, developments and their contribution to the area of analytical chemistry, relating relevant aspects of the development of electrochemical sensors in Brazil.

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Section: Potentiometric Sensorsmentioning

confidence: 99%

Electrochemical sensors: a powerful tool in analytical chemistry

Stradiotto¹,

Yamanaka²,

Zanoni³

2003

J. Braz. Chem. Soc.

316

148

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“…A carrier solution of low buffer capacity (pH = 7) was used to avoid zone acidity sample change 15,26 . The effect of the sample volume was investigated from 20 µL to 400 µL (changing the length of the sample loop in the commutator) with injection of buffer solution at pH 3 (see Figure 6).…”

Section: Flow Injection Parameters and Tubular Electrode Characteristicsmentioning

confidence: 99%

“…Tungsten 9,10 and antimony 11 oxides were studied as potentiometric electrodes as pH sensor in flow injection potentiometry. On the other hand, PVC has been used as the matrix and support for immobilization of various neutral carriers and ionophores [12][13][14][15] in the construction of electrodes for pH and acidity determination in FIA. Although the combination of ion selective electrodes and flow injection analysis allows the development of systems capable of eliminating interferences, these sensors exhibit small pH response ranges and short lifetimes.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of a Fe2O3-based graphite-epoxy tubular electrode as pH sensor in flow injection potentiometry

Teixeira¹,

Ramos²,

Cassiano³

et al. 2000

J. Braz. Chem. Soc.

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Uma avaliação sistemática de um eletrodo tubular de Fe 2 O 3 em grafite epóxi foi realizada através de medições de pH em um sistema de injeção em fluxo de linha única. O eletrodo tubular foi obtido pela deposição de uma mistura de óxido de ferro(III), pó de grafite e resina epóxi no interior de um orifício feito previamente no canal de injeção (de resina poliuretana). O efeito da composição do eletrodo e dos parâmetros do sistema de injeção em fluxo (vazão e volume amostra) sobre a resposta do eletrodo foram avaliados em quintuplicata (limite de confiança de 95%). A melhor resposta potenciométrica (E/mV = 178,2 -26,5 pH; r = 0,9995) foi obtida no intervalo de pH de 2 a 12 com um eletrodo de composição em massa 30% de Fe 2 O 3 , 20% de grafite e 50% de resina epóxi, volume de injeção de amostra de 300 µL e vazão de 3,2 mL min -1 . A frequência analítica foi 90 h -1 e um tempo de vida útil de pelo menos 6 meses (mais de 2000 determinações) foi obtido.A systematic evaluation of a Fe 2 O 3 graphite-epoxy tubular electrode was investigated through pH measurements in a single-channel flow injection system. The tubular electrode was obtained by deposition of a mixture of iron(III) oxide, graphite powder and epoxy resin into a hole previously made in the injection channel (of a polyuretane resin block). The effect of electrode composition and flow injection parameters (flow rate and injection sample volume) on the Fe 2 O 3 -tubularelectrode response was initially evaluated in quintuplicate (confidence level of 95%). The best potentiometric response (E/mV = 178.2 -26.5 pH; r = 0.9995) was reached in the pH range 2 to 12 with an electrode composition in mass of 30% Fe 2 O 3 , 20% graphite and 50% epoxy resin, injection sample volume of 300 µL and a flow rate of 3.2 mL min -1 . The frequency rate was 90 h -1 and a useful lifetime of at least six months (more than 2000 determinations) was obtained.

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