Three-dimensional voltammetry: Use of chronoamperometric E-t-i data to achieve second-order advantage

Area of Science:

• Analytical Chemistry
• Electrochemistry

Background:

• Developing selective electroanalytical methods is crucial for complex sample analysis.
• Traditional methods often struggle with uncalibrated interferences.
• Three-dimensional voltammetry (E-t-i) offers a richer data source for improved selectivity.

Purpose of the Study:

• To evaluate the potential of three-dimensional voltammetry (E-t-i) data for developing advanced electroanalytical methods.
• To assess the achievement of the "second-order advantage" using multivariate calibration algorithms.
• To determine analytes in complex matrices, such as ferrocyanide and acetaminophen in urine, with minimal interference.

Main Methods:

• Acquisition of potential-time-current (E-t-i) data using chronoamperometry with staircase waveform potentials.
• Application of multivariate calibration algorithms: Parallel Factor Analysis (PARAFAC) and Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS).
• Validation using model systems (ferrocyanide/hydroquinone) and real-world samples (acetaminophen in urine).

Main Results:

• Both PARAFAC and MCR-ALS algorithms successfully achieved the second-order advantage.
• Accurate prediction of analyte concentrations in validation synthetic samples was demonstrated.
• Excellent results were obtained for the direct analysis of acetaminophen in spiked urine samples using E-t-i data and MCR-ALS.

Conclusions:

• Three-dimensional voltammetry (E-t-i) coupled with multivariate algorithms provides a powerful approach for selective electroanalysis.
• The second-order advantage can be effectively leveraged to overcome matrix interferences in complex samples.
• MCR-ALS with E-t-i data shows significant promise for the direct determination of drugs in biological fluids like urine.