The Selection of “Green” Conditions for Components Identification in a Combined Medicine by TLC/HPTLC Methods

Abstract

Aim. To select “green conditions” for identifying components in a combined medicine for the treatment of alcohol intoxication.Materials and methods. Thin-layer chromatography and high performance thin-layer chromatography methods were used. An analytical GREEnness calculator was applied to assess the environmental friendliness of the analytical procedure.Results and discussion. The choice of mobile and stationary phases that comply with the principles of “green chemistry” and can be used to detect glutamic acid and glycine in the composition of a combined medicine has been substantiated. It has been determined that by the indicators Rf, Rs, ΔRf, α, N, H the most effective for the division is the ethanol (96 per cent) – water (70:30) mobile phase (the length of the solvent front is 10 cm, the application volume is 5 μL), which allows, in addition to amino acids, to determine another prescription component – ascorbic acid. The conditions for identification of substances by the high-performance thin-layer chromatography method (the length of the solvent front is 7 cm, the application volume is 2 μL) have been selected. It has been found that to detect chromatographic zones, it is optimal to use ninhydrin solution R1 with further heating of the plate at a temperature of 100-105°С for 5 min. The specificity of determination of glutamic acid, glycine and ascorbic acid in comparison with solutions of standard substances has been proven. While studying the robustness of the method the influence of chromatographic conditions on the final result (the impact of the stationary phase type, chamber saturation, application volume, distance from the “start line” to the “finish line”, the effect of the detection solution, stability of solutions for application) has been researched. The precision of the method on one and three plates of the same type has been studied; the intermediate precision has been researched. The calculated assessment of greenness of the analytical procedure is 0.66.Conclusions. As a result of the studies conducted, “green conditions” for identifying amino acids (glutamic acid, glycine), as well as ascorbic acid in a combined medicine by thin-layer chromatography and high-performance thin-layer chromatography methods have been selected. The validation characteristics of the method (specificity, robustness and precision) have been studied.