Croatica Chemica Acta, Vol. 85 No. 3, 2012.
Original scientific paper
https://doi.org/10.5562/cca2054
Current Minimum in Differential Pulse Polarography
Marina Zelić
; Division for Marine and Environmental Research, Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Ivanka Pižeta
; Division for Marine and Environmental Research, Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Dijana Jadreško
; Division for Marine and Environmental Research, Ruđer Bošković Institute, POB 180, 10002 Zagreb, Croatia
Abstract
Current minimum, which sometimes appears as a part of the net response in differential pulse polarography (DPP), was studied in systems characterized by a pronounced IR drop or reactant adsorption. Experimental results obtained on a static mercury drop electrode (SMDE) clearly indicate that this effect is highly influenced not only by solution resistance (or intentionally added resistors) and reactant concentration, but also by both timing parameters (drop time, pulse duration) and electrode surface area. Presentation of the net response along with its components, demonstrates that the current minimum originates from the maximum on dc component, minimum on pulse component or both. In practice, DPP minimum, obtained in measurements with a SMDE, can be treated as an additional diagnostic parameter for the recognition of reactant adsorption or poor experimental conditions (i.e. high resistance within electrode system or low conductivity of the electrolyte medium). (doi: 10.5562/cca2054)
Keywords
current minimum; IR drop; reactant adsorption; components of the net response; differential pulse polarography
Hrčak ID:
92099
URI
Publication date:
31.10.2012.
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