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Which Potential steps or waveforms are typically used in PAD?

In PAD of carbohydrates a series of potentials is applied in a continuous cyclic manner.

During time interval t1 the detection potential is applied. The data collection occurs within t1, during time interval ts (sampling time). The time difference t1 - ts is the stabilization time.

During the next time intervals (t2..t4) the electrode is ‘cleaned’ by reductive and oxidative potential steps.

Several considerations are important for the choice of the pulse duration. Optimization is depending on the working electrode material, the sample constituents and the required detection frequency. The impression may arise that the number of variables, 5 potential steps and 6 time settings, may lead to a time-consuming optimization procedure. In practice, the pulse mode is more straightforward and published in several excellent review papers and application notes.

Most often used potential programs are 3 and 4 step PAD waveforms.

A 3 step waveform leads to a faster degeneration of the working electrode than a 4 step waveform. Therefore, we recommend using a FlexCell with easy to exchange gold working electrode whenever a 3 step waveform is used. When a 4 step waveform is used, the lifetime of the working electrode is much longer and therefore we recommend to use a SenCell to get the best sensitivity in 4-step PAD.

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