Analytics of biologically active derivatives of electrostatically stabilized silanates by isotachophoresis

Analytics, Properties and Applications of Biologically Active Stilbene Derivatives

Stilbene and its derivatives belong to the group of biologically active compounds. Some derivatives occur naturally in various plant species, while others are obtained by synthesis. Resveratrol is one of the best-known stilbene derivatives. Many stilbene derivatives exhibit antimicrobial, antifungal or anticancer properties. A thorough understanding of the properties of this group of biologically active compounds, and the development of their analytics from various matrices, will allow for a wider range of applications. This information is particularly important in the era of increasing incidence of various diseases hitherto unknown, including COVID-19, which is still present in our population. The purpose of this study was to summarize information on the qualitative and quantitative analysis of stilbene derivatives, their biological activity, potential applications as preservatives, antiseptics and disinfectants, and stability analysis in various matrices. Optimal conditions for the analysis of the stilbene derivatives in question were developed using the isotachophoresis technique.

Isotachophoresis: Theory and Microfluidic Applications

Isotachophoresis (ITP) is a versatile electrophoretic technique that can be used for sample preconcentration, separation, purification, and mixing, and to control and accelerate chemical reactions. Although the basic technique is nearly a century old and widely used, there is a persistent need for an easily approachable, succinct, and rigorous review of ITP theory and analysis. This is important because the interest and adoption of the technique has grown over the last two decades, especially with its implementation in microfluidics and integration with on-chip chemical and biochemical assays. We here provide a review of ITP theory starting from physicochemical first-principles, including conservation of species, conservation of current, approximation of charge neutrality, pH equilibrium of weak electrolytes, and so-called regulating functions that govern transport dynamics, with a strong emphasis on steady and unsteady transport. We combine these generally applicable (to all types of ITP) theoretical discussions with applications of ITP in the field of microfluidic systems, particularly on-chip biochemical analyses. Our discussion includes principles that govern the ITP focusing of weak and strong electrolytes; ITP dynamics in peak and plateau modes; a review of simulation tools, experimental tools, and detection methods; applications of ITP for on-chip separations and trace analyte manipulation; and design considerations and challenges for microfluidic ITP systems. We conclude with remarks on possible future research directions. The intent of this review is to help make ITP analysis and design principles more accessible to the scientific and engineering communities and to provide a rigorous basis for the increased adoption of ITP in microfluidics.

Determination of Mercury Content in Surface Waters Using an Environmentally Non-Toxic Terminating Electrolyte

The paper presents results of the research on the dynamics of changes in the concentration of mercury in surface waters. The importance of mercury as an environmental pollutant results from specific properties of this metal, many sources of contamination, volatility, mobility, stability and high toxicity of its specific chemical forms. Samples of surface water collected from three rivers: the Bug, the Liwiec and the Muchawka were analysed. The Muchawka River flows into the Liwiec River, which in turn is a tributary of the Bug River. The technique of isotachophoresis was employed, using a solution of a biodegradable and environmentally non-toxic derivative of electrostatically stabilised silanates as the terminating electrolyte. The highest average mercury concentration of 0.89 μg/dm³ was determined in water samples collected from the Bug River in January, whereas the lowest concentration of 0.42 μg/dm³ was recorded in water collected from the Muchawka River in September.

The challenge of separating and determining biologically active electrostatically stabilized silanates using the high-performance liquid chromatography technique

We present the results of research on the optimal conditions for the separation and determination of newly obtained hypercoordinated compounds, which belong to the group of electrostatically stabilized silanates. The research involved five stationary and four mobile phases. The best selectivity was obtained using the graphite phase and the mobile phase consisting of acetonitrile/water (80/20). The maximum selectivity of the determined electrostatically stabilized silanates was 1.13 and 1.06 for (1), (2), (3); 1.10 and 1.15 for (4), (5), (6); and 1.12 and 1.15 for (7), (8), (9). The octadecyl phase (which is recommended as standard) did not yield satisfactory results.

Analytics and Application of Biologically Active Pentacoordinate Electrostatically Stabilized Silanates

The objective of this study was to synthesize information on the analytics, using two separation techniques, and the application of electrostatically stabilized silanate derivatives. They are biologically active, water-soluble, hydrolytically stable and biodegradable. Some of these compounds are used as plant growth regulators, while others, with higher molecular mass and lower electrophoretic mobility, are used in the form of terminating electrolytes in isotachophoresis, which is regarded as one of the green chemistry techniques. Two compounds were successfully used in the form of terminating electrolyte solutions, i.e. 4,4'-bis{1-(perhydroazepiniomethyl)[spirobi(1-sila-2,5-dioxacyclopentane-3-on)]at}, and 4,4'-bis{1-[(N,N-dimethyl)aminiomethyl]spirobi(1-sila-2,5-dioxacyclopentane-3-on)at} to isolate organic ionic substances with high molecular mass, e.g. derivatives of quinoline, stilbene and electrostatically stabilized silanates (ES-silanates). Establishing the best conditions for the analysis of these derivatives extends the possibilities of conducting research on their biological activity and miscellaneous applications. Furthermore, the terminating electrolytes used in the form of solutions of electrostatically stabilized silanates allow the analysis of both cationic and anionic forms.