ISSN:
1089-7623
Source:
AIP Digital Archive
Topics:
Physics
,
Electrical Engineering, Measurement and Control Technology
Notes:
A PARC174A polarographic analyzer has been transformed into a comprehensive microcomputer controlled electroanalytical system by interfacing it with an IBM PC equipped with a Tecmar LabMaster data acquisition subsystem. Techniques implemented include square wave voltammetry, chronoamperometry, cyclic voltammetry, differential pulse, normal pulse, and sampled dc polarography, and stripping voltammetry which can be used with either linear sweep, differential pulse, or square-wave techniques. The PARC174A functions only as a potentiostat and current to voltage converter. All the potential waveforms are generated by the D/A converter of the LabMaster and the current data are sampled by the A/D converter. The software developed should be easily adaptable to most potentiostats with minor modification. Because no extra circuitry is desired to complicate the system, a small-step staircase waveform is used to approximate the linear dc ramp in cyclic voltammetry, differential pulse, and sampled dc techniques. The discrepancy in results obtained using linear dc ramp and small-step staircase waveforms was carefully examined and proven to be negligible. All the techniques implemented have been shown to give theoretically predicted results. The results are also found essentially the same as those obtained using a conventional PARC174A. This computer controlled system makes available the use of square wave voltammetry, which was otherwise not available on the original machine. Experimental data showed that 4.76×10−8 M Cd2+ could be quantitatively analyzed by square wave voltammetry when a dropping mercury electrode was used.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.1144015
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