1 research outputs found
Improving the Voltammetric Quantification of Ill-Defined Peaks Using Second Derivative Signal Transformation: Example of the Determination of Platinum in Water and Sediments
The
determination of trace elements using stripping voltammetry
may be seriously affected by the presence of intensive matrix background
or interfering peaks, leading to poorer detection limits and/or inaccurate
quantitative results. In this work, we have tested the use of signal
transformation (e.g., second derivative) in the analysis of platinum
in seawater and sediment digests by means of catalytic adsorptive
stripping voltammetry. In natural waters, the limit of detection of
Pt is affected by a broad background wave due to the formazone complex
used in the sample matrix for its determination, while in sediment
digests, the Pt peak may be interfered with due to the presence of
elevated concentrations of Zn, affecting the accuracy of the determination.
Results applying second derivative signal transformation revealed
a significant improvement (2ā3-fold) of the detection limit
in water due to the minimization of background effects, therefore
allowing shorter accumulation times and faster determinations. In
the presence of interfering peaks, the inaccuracy resulting from erroneous
baseline selection in the original signal is eliminated when the second
derivative is used. Signal processing should be considered as a useful
tool for other voltammetric methodologies where more accurate or faster
determinations are needed