Electrochemical Oxidation of Astaxanthin on Glassy-carbon Electrode and its Amperometric Determination Using Batch Injection Analysis (BIA)

Batch injection analysis in tandem with electrochemical detection: the recent trends and an overview of the latest applications (2015–2020)

The purpose of the proposed review is to refer the contemporary capability of automated analytical systems, in particular batch injection analysis (BIA) in connection with electrochemical detection, for widespread applications in analytical chemistry. This combination recently represents an efficient tool for improvement of method parameters, such as speed, selectivity, and sampling rate for sensing of miscellaneous organic and inorganic substances. The review is focused on conception and usage of BIA in tandem with electrochemical detection utilizing various techniques, namely amperometry, voltammetry, and multiple pulse amperometry, as well as design of electrochemical cells constructed for BIA systems is discussed. Finally, this paper also summarizes the comprehensive overview of works published from 2015 to 2020 dealing with the electrochemical determination of different analytes by BIA in various matrices.

Electrochemistry as a screening method in determination of carotenoids in crustacean samples used in everyday diet

Electrochemistry of carotenoids has attracted a lot of interest because it provides an understanding of their oxidative properties. We report the application of electrochemistry in the analysis of carotenoids. Voltammetry of microdroplets immobilized on paraffin impregnated graphite electrode in 0.1 mol dm^-3 HClO₄ and KNO₃ aqueous electrolytes using square-wave voltammetry was applied. Previous studies have shown that carotenoids undergo complex oxidation process when characterized in aqueous media. In this research, the electrooxidation of carotenoid astaxanthin was confirmed. The obtained response allowed the development of an electroanalytical method with a limit of detection of 15.77 µmol dm^-3, the limit of quantification of 47.80 µmol dm^-3 and acceptable relative standard deviations for current (3.69%) and potential (0.41%). Extraction using DMSO and acetone has shown to be appropriate for voltammetric analysis. Astaxanthin content was determined electrochemically in shrimp and soft-shell crab samples (20.63 and 6.59 μg g^-1, respectively), yielding recoveries above 90%.