Automatic mercury drop electrode with double solenoid activated valve

Pedrotti, Jairo J.; Angnes, Lúcio; Gutz, Ivano Gebhardt Rolf

doi:10.1002/elan.1140040606

Cited by 13 publications

(14 citation statements)

References 36 publications

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“…A Rainin programmable pipettor, Model EDP Plus of 100 mL, was employed to inject the samples. Slightly modi®ed versions of the AME [28] were employed throughout the work. When not otherwise indicated, the results refer to a drop area of 1.82 mm 2 , calculated from the average of the drop mass determined to 0.01 mg.…”

Section: Instrumentationmentioning

confidence: 99%

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A Batch Injection Analysis System for Ascorbic Acid Determination Using Amperometric Detection on a Sessile Mercury Drop Electrode

Donato

Pedrotti

Gutz³

1999

Electroanalysis

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A batch injection analysis (BIA) system, which uses an automatic mercury electrode (AME) as an amperometric detector, is described. The capillary of this AME was adapted in an inverted position through the bottom of a simple cylindrical electrochemical cell, in order to generate more stable sessile drops and to grant free access for the tip of the programmable micropipettor. The BIA system was evaluated by using the electrochemical oxidation of L-ascorbic acid to dehydroascorbic acid on the sessile mercury drop electrode. Acetate buffer solution (50 mM, pH 4.8) was used as supporting electrolyte. The working electrode was operated at 0.230 V (vs. Ag/AgCl). The effect of the dispensing rate, of the dispensed volume, of the distance between the mercury drop and the pipettor tip, as well as of the solution level in the cell were evaluated. Injections of 50 mL were suitable to reach a detection limit of about 2.5 mM (450 ppb). At the 50 mM ascorbic acid level, an RSD of 1.6 % (N 35) was observed with or without mercury drop renewal between injections. A frequency of 300 injections per hour may be reached when the drop is renewed sporadically. The new BIA method was applied to the determination of ascorbic acid in packedacanned tropical fruit juices. Selectivity was granted by differential measurements of the peak current before and after exposure of samples to ascorbate oxidase (from cucumber).

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Section: Instrumentationmentioning

confidence: 99%

“…An automatic mercury drop electrode (AME), formerly developed [28], works at any position and can be used with the glass capillary upwards to generate sessile drops.…”

Section: Introductionmentioning

confidence: 99%

A Batch Injection Analysis System for Ascorbic Acid Determination Using Amperometric Detection on a Sessile Mercury Drop Electrode

Donato

Pedrotti

Gutz³

1999

Electroanalysis

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“…As noted above, the slope f of the straight lines is rather constant if the mercury flow rate during extrusion, the final drop area and the sampling time (t 1 or t 2 ) are maintained invariant, and its value needs to be determined only once during a calibration experiment (like Table 1). Subsequently, it is sufficient to measure sets of Q ext and DQ as a function of the [18] and (+) Grahame [19].…”

Section: Resultsmentioning

confidence: 99%

“…In principle, other electrodes can be adapted for the determination of surface charge density by the method proposed here, such as the simplified and more compact version of this automatic mercury electrode, designed for electroanalysis [19], or commercial mercury electrodes (e.g. from Metrohm, Radiometer, BAS or EG&G-PAR), operated in static mercury drop electrode (SMDE) mode.…”

Section: Mercury Drop Electrodementioning

confidence: 99%

Determination of the surface charge density of a mercury electrode by extrusion: a new method for correction of the faradaic component

Brito

Angnes

Brett

et al. 1999

Journal of Electroanalytical Chemistry

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The accurate determination of the surface charge density at the mercury solution interface by the method of extrusion of mercury drops is impaired by the faradaic current caused by traces of electroactive species. This paper describes a new design of a hanging mercury drop electrode with accurate control of the extruded electrode area, to within 0.1%, together with a new and reliable procedure for correction of the faradaic current. The procedure is based on first obtaining the correction parameters in the presence of increasing amounts of electroactive species and then using these parameters for correction of the faradaic component so as to obtain the surface charge density of the electrode. Implementation of the method with a microcomputer controlled system provides automatic acquisition of corrected electrode charge density values as a function of the electrode potential. The results obtained with this new method are in excellent agreement with those obtained by other methods, as illustrated for aqueous sodium fluoride solution.

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“…This process initiated by Professor Heyrovsky ¬ resulted in commercially available reliable mercury electrodes suitable for nanomolar and subnanomolar concentrations. Further progress in this field can be documented by the above mentioned articles of Novotny and Kowalski and by papers of Gutz on versatile automatic mercury drop electrode [19,20]. ± Development of measuring techniques that proceeded from classical DC polarography [2], through oscillopolarography [21], Kalousek×s switcher [22], AC polarography [23], tast polarography [24], normal pulse polarography [25], differential pulse polarography [26], square-wave voltammetry [27], cyclic voltammetry [28], anodic stripping voltammetry [29], adsorptive stripping voltammetry [30], convolution techniques [31,32] and elimination methods [33,34].…”

Section: Historymentioning

confidence: 99%

Eighty Years of Polarography – History and Future

Barek

Zima

2003

Electroanalysis

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Since 1922, when Professor Jaroslav Heyrovsky ¬ carried out his pioneering experiment with a dropping mercury electrode, polarography showed remarkable ability to adjust to ever increasing demands on the sensitivity and selectivity and up to now mercury electrodes are among the best sensors for electroanalytical measurements. The aim of this contribution is to show both the historical development of these techniques and their presence and possible future developments and to show that even today in certain cases polarographic and voltammetric techniques on mercury electrodes can successfully compete with modern separation and spectrometric techniques.

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Automatic mercury drop electrode with double solenoid activated valve

Cited by 13 publications

References 36 publications

A Batch Injection Analysis System for Ascorbic Acid Determination Using Amperometric Detection on a Sessile Mercury Drop Electrode

A Batch Injection Analysis System for Ascorbic Acid Determination Using Amperometric Detection on a Sessile Mercury Drop Electrode

Determination of the surface charge density of a mercury electrode by extrusion: a new method for correction of the faradaic component

Eighty Years of Polarography – History and Future

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