Determination of pharmaceutical thiols by liquid chromatography with electrochemical detection: Use of an electrode with a conductive carbon cement matrix, chemically modified with cobalt phthalocyanine

Favaro, Gabriella; Fiorani, Mario

doi:10.1016/0003-2670(96)00265-6

Cited by 59 publications

(25 citation statements)

References 17 publications

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“…A 1 mL portion of the solution was diluted in a voltammetric cell to 10 mL of 0.1 M phosphate buffer (pH 7.00) and 0.1 M LiClO 4 , and the cyclic voltammogram was recorded. Effervescent C tablets: A 100 mg portion of a finely powdered sample was dissolved in a 50 mL flask with bidistilled water.…”

Section: Procedures For Pharmaceutical Preparationsmentioning

confidence: 99%

Electrocatalytic Determination of Ascorbic Acid at the Surface of 2,7‐Bis(ferrocenyl ethyl)fluoren‐9‐one Modified Carbon Paste Electrode

et al. 2006

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A chemically modified carbon paste electrode with 2,7-bis(ferrocenyl ethyl)fluoren-9-one (2,7-BFEFMCPE) was employed to study the electrocatalytic oxidation of ascorbic acid in aqueous solution using cyclic voltammetry, differential pulse voltammetry and chronoamperometry. The diffusion coefficient (D ¼ 1.89 Â 10 À5 cm 2 s À1), and the kinetic parameter such as the electron transfer coefficient, a (¼ 0.42) of ascorbic acid oxidation at the surface of 2,7-BFEFMCPE was determined using electrochemical approaches. It has been found that under an optimum condition (pH 7.00), the oxidation of ascorbic acid at the surface of such an electrode occurs at a potential about 300 mV less positive than that of an unmodified carbon paste electrode. The catalytic oxidation peak currents show a linear dependence on the ascorbic acid concentration and linear analytical curves were obtained in the ranges of 8.0 Â 10 À5 M -2.0 Â 10 À3 M and 3.1 Â 10 À5 M -3.3 Â 10 À3 M of ascorbic acid with correlation coefficients of 0.9980 and 0.9976 in cyclic voltammetry and differential pulse voltammetry, respectively. The detection limits (2d) were determined to be 2.9 Â 10 À5 M and 9.0 Â 10 À6 M with cyclic voltammetry and differential pulse voltammetry, respectively. This method was also examined for determination of ascorbic acid in pharmaceutical preparations.

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Section: Procedures For Pharmaceutical Preparationsmentioning

confidence: 99%

Electrocatalytic Determination of Ascorbic Acid at the Surface of 2,7‐Bis(ferrocenyl ethyl)fluoren‐9‐one Modified Carbon Paste Electrode

et al. 2006

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“…These procedures include capillary electrophoresis [13], high-performance liquid chromatography (HPLC) [3,4,5,9], polarography [10], voltammetry [23], coulometry [20], amperometry [18], conductometry [19], fluorimetry [12] , colorimetry [1,2,7,14,22,24] and flow injection methods. [12,21,28].…”

Section: Introductionmentioning

confidence: 99%

Potentiometric determination of captopril in pharmaceutical formulations

et al. 2003

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A simple, precise, rapid and low-cost potentiometric method for captopril determination in pure form and in pharmaceutical preparations is proposed. Captopril present in tablets containing known quantity of drug was potentiometrically titrated in aqueous solution with NaOH using a glass pH electrode, coupled to an autotitrator. No interferences were observed in the presence of common components of the tablets as lactose, microcrystalline cellulose, croscarmellose sodium, starch and magnesium stearate. The analytical results obtained by applying the proposed method compared very favorably with those obtained by the United States Pharmacopoeia Standard procedure. Recovery of captopril from various tablet dosage formulations range from 98.0 to 102.0%.

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“…The literature shows that high-performance liquid chromatography (HPLC) is a major technique used for the determination of captopril in pharmaceutical formulations [24][25][26], in plasma and urine for pharmacokinetic studies [27,28].…”

Section: Introductionmentioning

confidence: 99%