Liquid-liquid Extraction Coupled to Batch Injection Analysis for Electroanalysis of Levofloxacin at Low Concentration Level

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.

Sol-gel hydrothermal synthesis of nano crystalline silicotitanate and its strontium and cesium adsorption

Crystalline silicotitanate (CST) was synthesized via a sol-gel hydrothermal method using Na₂Si₂O₃·9H₂O and TiCl₄ as silicon and titanium sources. The effects of pH, silicon concentration, hydrothermal temperature, and time on the CST synthesis were studied at a fixed molar ratio of silicon:titanium (0.98:1). Pure nano-CST crystals were synthesized at pH = 12.5, silicon concentration of 5 g L^-1, 170 °C for 7 days. The average CST particle size was < 100 nm, with a Sr²⁺/Cs⁺ distribution coefficient up to 1.9 × 10⁶ mL g^-1/9.4 × 10³ mL g^-1 under the optimum conditions. In addition, nano-CST absorbed Sr²⁺/Cs⁺ over a wide pH range. The nano-CST also displayed a much faster equilibrium time, 4 h, as compared with previous studies. Furthermore, nano-CST adsorption of Sr²⁺/Cs⁺ followed a Langmuir adsorption model and was consistent with pseudo-second-order kinetics.

Boron Doped Diamond Electrodes in Flow-Based Systems

Boron-doped diamond (BDD) electrodes present several notable properties, such as the largest potential window of all electrode materials (especially in anodic potentials), low background and capacitive currents, reduced fouling compared to other electrodes, mechanical robustness, and good stability over time. On the other hand, flow-based systems are known as well-established approaches to minimize reagent consumption and waste generation and with good compromise between sample throughput and analytical performance (mechanization of chemical assays). This review focuses on the use of BDD electrodes for electrochemical detection in flow systems, such as flow injection analysis (FIA), batch injection analysis (BIA), high performance liquid chromatography (HPLC), and capillary electrophoresis (CE). The discussion deals with the historical evolution of BDD, types of electrochemical pre-treatments (cathodically/H-terminated or anodically/O-terminated), cell configurations, and analytical performance. Articles are discussed in chronological order and subdivided according to the type of flow system: FIA, BIA, HPLC, and CE.