Adsorptive stripping voltammetry of riboflavin and other flavin analogs at the static mercury drop electrode

Wang, Joseph.; Luo, Den Bai.; Farias, Pércio Augusto Mardini; Mahmoud, Jawad S.

doi:10.1021/ac00279a039

Cited by 88 publications

(24 citation statements)

References 30 publications

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“…The peak potential (E p ) stayed constant in all this experiment. The lowest ionic strength was very effective for the adsorptive accumulation of the Mifepristone on the electrode as described by Wang in the behavior of riboflavine in a medium of 1 mM NaOH [10].…”

Section: Square-wave Voltammetry Swvmentioning

confidence: 74%

Voltammetric Behavior of Mifepristone (RU‐486) Using Square‐Wave and Adsortive Stripping‐Wave Techniques. Determination in Urine Samples

et al. 2004

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The behavior of Mifepristone (RU-486) was studied by square-wave technique, leading to two methods for its determination in aqueous samples and urine samples at pH 2. The application of the square-wave (SW) without the adsorptive accumulation and stripping voltammetric (AdSV) show the maximum response at À 0.896 V using an accumulation potential of À 0.5 V. The effect of experimental parameters that affect this determination are discussed. For the stripping technique, Mifepristone proved to be more sensitive, yielding signals four times larger than those obtained by applying a square-wave scan without the previous accumulation. The calibration plot to determine Mifepristone was linear in the range 2.4 Â 10 À8 and 5.4 Â 10 À7 M by stripping mode with an accumulation time t acc of 30 s. The relative standard deviation obtained for concentration levels of Mifepristone as low as 2.0 Â 10 À7 M with square-wave was 1.17% (n 10) and with stripping square-wave 2.02% (n 10) in the same day. The two proposed methods (SW and SWAdSV) were applied to the determination of Mifepristone in urine.

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Section: Square-wave Voltammetry Swvmentioning

confidence: 74%

Voltammetric Behavior of Mifepristone (RU‐486) Using Square‐Wave and Adsortive Stripping‐Wave Techniques. Determination in Urine Samples

et al. 2004

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“…Based on these results, it can be confirmed that the chemical structure of riboflavin was destroyed in the CL reaction. The reasonable explanation may be that HSO 5 − is decomposed by the catalysis of Co 2+ , and produce reactive species (SO 4 •− , SO 5 •− , etc.) [24], which are strong oxidants leading to the oxidization of riboflavin, and the process of oxidization is a slow reaction comparing with the CL emission.…”

Section: Possible Mechanismmentioning

confidence: 99%

“…Routine methods for the determination of riboflavin were based on its natural fluorescence [1,2]. Additionally, riboflavin was also determined by chemically modified electrode [3,4] depending upon its electrical activity. Certainly, IR [5] and spectrophotometry [6] were used for its determination in the relative literature.…”

Section: Introductionmentioning

confidence: 99%

Determination of riboflavin by enhancing the chemiluminescence intensity of peroxomonosulfate–cobalt(II) system

Wang

Zhao

Liu

et al. 2007

Spectrochimica Acta Part A: Molecular and Biomolecular Spectros

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“…Due to its adsorptive property, electroanalytical measurements of riboflavin were mainly involved in adsorptive stripping voltammetry at mercury electrodes [17 -19] and electrochemically activated glassy carbon electrodes [20 -21]. At static mercury drop electrode [17], i.e., hanging mercury drop electrode (HMDE), the detection limit of 2.5 Â 10 À11 M was obtained, but the toxity of mercury limited its application.…”

Section: Introductionmentioning

confidence: 99%

Adsorptive Stripping Analysis of Riboflavin at Electrically Heated Graphite Cylindrical Electrodes

Sun

Lin

et al. 2007

Electroanalysis

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Electrically heated graphite cylindrical electrodes (HGCEs) made from ground pencil leads have been used to perform adsorptive stripping square wave voltammetry (SWV) measurements of trace riboflavin (RF). The SWV stripping peak current was significantly enhanced with increasing the electrode temperature only during preconcentration step. This enhancement was due to the forced thermal convection induced by heating the electrode rather than the bulk solution. It is the thermal convection that has the ability to improve mass transfer and facilitate adsorption thus enhance stripping responses. It was found that the detection limit of 5 Â 10 À9 M (S/N ¼ 3) could be obtained at an electrode temperature of 72 8C during 5 min accumulation, more than one magnitude lower than that at 22 8C (room temperature), the sensitivity could be enhanced ca. eight or four folds for two different RF concentration ranges. So it is possible to develop a new highly sensitive method to determine riboflavin at HGCEs. Such HGCEs were also successfully used to determine RF in multivitamin tablets.

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Adsorptive stripping voltammetry of riboflavin and other flavin analogs at the static mercury drop electrode

Cited by 88 publications

References 30 publications

Voltammetric Behavior of Mifepristone (RU‐486) Using Square‐Wave and Adsortive Stripping‐Wave Techniques. Determination in Urine Samples

Voltammetric Behavior of Mifepristone (RU‐486) Using Square‐Wave and Adsortive Stripping‐Wave Techniques. Determination in Urine Samples

Determination of riboflavin by enhancing the chemiluminescence intensity of peroxomonosulfate–cobalt(II) system

Adsorptive Stripping Analysis of Riboflavin at Electrically Heated Graphite Cylindrical Electrodes

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