PV220TM Pulse Voltammetry Software |
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For a complete description of the features and capabilities of the PV220, click here to open the PV220 brochure. You'll need Adobe Acrobat Reader. The PV 220TM Pulse Voltammetry Software is the electroanalytical tool to perform qualitative and mechanistic analysis of electrochemical species. The PV220 adds Differential Pulse Voltammetry, Square Wave Voltammetry and other recognized pulse voltammetry techniques to the GamryTM software product family. In conjunction with a Gamry Potentiostat and its low current measuring capabilities, the PV220 lowers the concentration limits of measurement. The sensitivity of the pulse techniques, achieved by exploiting the difference in the decay rates between the charging and faradaic currents, allows detection of low concentrations of electroactive species. The PV220 is also capable of stripping analysis to further enhance the detection limit. The PV220 is an excellent companion to Gamry’s PHE200 Physical Electrochemistry Software for cyclic voltammetry, chronoamperometry, chronopotentiometry, and controlled potential coulometry. Physical electrochemists and electroanalytical chemists will find that the PV220-PHE200 will meet most of their electrochemical measurement requirements. The PV220 Pulse Voltammetry System is a compact system that mates to virtually any electrode: solid, rotating, or mercury. The PV220 incorporates the following pulse techniques: Square Wave Square Wave VoltammetryIn recent years, Square Wave Voltammetry has become very popular because the timescale is much faster than other pulse techniques. The scan rate in Square Wave may be as high as 50 V/sec with little or no sacrifice in sensitivity compared to Differential Pulse! In addition, the forward currents, the reverse currents, and the difference currents can be plotted with the PV220. This is useful in determining the reversibility of your redox system. Large forward currents with no corresponding reverse currents indicate a non-reversible or quasi-reversible system. A variety of different electrode configurations can be used with the PV220. These include solid electrodes, mercury drop electrodes, and rotating disk electrodes. Selection is made at the beginning of the experiment with the Electrode Setup panel. If you’re using a mercury drop electrode, you have a choice of configurations; dropping, hanging or static mercury drop, (useful for polarography or stripping analysis.) If you are using a rotating disk electrode, you have full control of the rotation rate from the PV220. When you check the Rotating Electrode radio button, a new dialog box appears enabling you to select the rotation rate. Normal Pulse, Reverse Normal Pulse, and Differential Pulse Voltammetry
During
Normal Pulse Voltammetry, pulses of increasing amplitude are applied
from the Initial Potential. The current response is measured at the end of the pulse and
then plotted against potential. Measurement
of the current at the end of the pulse allows for differentiation between the charging current and the faradaic
current of interest. During Reverse Normal Pulse Voltammetry, the voltage profile is inverted compared to Normal Pulse. The first part of the pulse cycle has the voltage stepped and then the voltage is returned to the Initial Voltage and the current is measured. This profile enhances the response of reaction products whereas Normal Pulse favors the reactants. In Differential Pulse Voltammetry, the pulse waveform is superimposed on a voltage ramp. The current is sampled immediately prior to the application of the pulse and at the end of the pulse and the difference is recorded. This gives rise to a differential current response. This technique is used when very low quantities of compound are present. Sampled D.C.Voltammetry Sample DC Voltammetry involves sweeping the voltage with a staircase waveform and sampling the current immediately prior to each voltage step. The measured voltammogram exhibits a much smoother response than traditional DC polarography, (increasing the detection limit). Generic PulseThe PV220 also incorporates a user-defined pulse technique, which allows you to apply a repeating pulse waveform of any size and duration. This technique works in both potentiostatic and galvanostatic modes. The potentiostatic mode has applications in chromatographic detection and also electrode conditioning. The galvanostatic mode is particularly useful for applications such as pulse plating. Systems InformationThe PV220TM Pulse Voltammetry Software requires a Gamry Potentiostat to conduct experiments. Gamry Instruments can supply complete systems including Potentiostat and Software installed in a desktop or notebook computer. Custom computer configurations, software, training and installation are available by special order. Contact us for further details on these systems.
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Last revised on Tuesday, June 17, 2008
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