I am studying the trace elemental analysis of heavy metal ions in water by electrochemical techniques. Literature reports mainly have demonstrated the use of ASV techniques like LSASV (linear sweep), SWASV (square wave) and DPASV (differential pulse). But I find no explanation as to why and how the particular technique was chosen. Can anyone here please explain what are the main differences between these techniques and how do they affect the measurement? Also what advantages/ disadvantages does CV have over ASV techniques?
This links will help you
https://www.edaq.com/w/images/d/d2/EXP001_Anodic_Stripping_Voltammetry_PDF.pdf
https://www.sciencedirect.com/science/article/pii/S1878535209000392
Hi Keya,
The main differences are the detection limits of the assessed metals. The use of DPASV has the avantage using differential pulses to reach low concentrations due to lowring the charge /decharge capacitive current of the double layer. Which is not the case for the other electrochemical techniques.
1. Any ASV vs. CV has the advantage of the deposition/accumulation step. This step acts as a preconcentration step, allowing lower detection limits.
2. DP and SW vs. LS have the advantage of measuring only the faradaic currents (in the right moment when the capacitive current is decayed). Only the faradaic current is related to the analyte concentration. This feature means lower noise during measurements, also allowing lower detection limits.
Please look at the following below links which may help you in your analysis:
https://www.brown.edu/Departments/Engineering/Courses/En123/Lectures/potentiostat.pdf
https://iopscience.iop.org/article/10.1088/1742-6596/466/1/012023/pdf
Thanks
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