RP TLC Analysis of New Antidepressants in Pharmaceutical Preparations

JPC – Journal of Planar Chromatography – Modern TLC - A simple and precise reversed-phase thin-layer chromatographic (RP TLC) method for simultaneous separation of fluoxetine and...     

RP TLC Determination of the Lipophilicity of Anticancer-Active Propargyl Thioquinolines

JPC – Journal of Planar Chromatography – Modern TLC - The lipophilicity of fifteen anticancer-active propargyl thioquinolines has been determined by reversed-phase thin-layer...     

The Use of Encoded Structural Data to Predict the Liquid Chromatographic Retention Behavior of Tetradentate Metal Complexes

Abstract

Retention data for tetradentate metal complexes of copper and nickel are reported for microparticulate silica and reversed phase columns. An attempt is made to relate structure and stability constant data to the retention volume by means of multiple linear regression. The results indicate that if the structure is encoded by means of dummy variables it may be possible to predict retention volumes of metal complexes. There is not a strong correlation between the value of the stability constants for the metal diamine and metal ketone complexes and the retention volume.     

Use of Photocatalytic Reactions to Visualize Drugs in TLC

JPC – Journal of Planar Chromatography – Modern TLC -     

Study of Lipophilicity and Application of Selected Structural Descriptors in QSAR Analysis of Nicotinic Acid Derivatives. Investigations on RP18WF254 Plates. Part II

JPC – Journal of Planar Chromatography – Modern TLC - Nicotinic acid (NAC) and its derivatives methyl nicotinate (MN), ethyl nicotinate (EN), isopropyl nicotinate (IPN), butyl...     

Structural Synthon Approach to Predict the Possible Polytypes of Layered Double Hydroxides

The complete universe of possible polytypes of layered double hydroxides (LDH) is predicted on the basis of symmetry arguments. A single [MX₂] (X = OH) layer, also defined as a structural synthon, belongs to the layer group P$\bar{3}$ 2/m1. These layers can be stacked in such a way as to conserve the unique 3‐axis of the layer in the resultant crystal. The different stacking sequences that facilitate symmetry conservation, yield the different possible polytypes of rhombohedral and hexagonal symmetries. More polytypes can be envisaged by including stacking sequences that systematically destroy the principal symmetry elements of the structural synthon. Thereby, stacking sequences that destroy the 3‐axis, while retaining the 2‐axis, yield possible polytypes of monoclinic symmetry. The nitrate‐containing LDH of zinc and aluminum crystallizes in a faulted structure in which, the planar faults are shown to arise on account of stacking sequences whose local symmetry is monoclinic. This approach to polytype prediction expands on an earlier reported method by Bookin and Drits and is very general with important implications for other classes of layered materials.     

用新定义的结构信息指数mH预测氯代苯类化合物的正辛醇/水分配系数

在分子拓扑理论的基础上,根据分子中原子的结构特征和键的连接性,提出了一个新的结构信息连接性指数^mH,并用^mH研究了多氯联苯、氯代羟基苯甲醛的正辛醇／水分配系数Kow。^mH不仅对这些化合物具有良好的结构选择性,而且与正辛醇／水分配系数的logKow值有优秀的相关性。新指数物理意义明确,计算简单,由方程得出的预测值与实验值之间能很好地吻合。     

Study of the Retention Behavior of Newly Synthesized s-Triazine Derivatives in RP TLC Systems,and the Lipophilicity of the Compounds

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of nine newly synthesized s-tri-azines has been studied by thin-layer chromatography on C18/UV254...     

The Correlations between Capacity Factors k′ and RM Values in Liquid Column and Thin-Layer Chromatography

Abstract

The purpose of this studie being carried out is to define some regularities between Thin-layer and Liquid Column Chromatography; i.e. between experimental obtained and theotetical calculated R_M-values and experimental obtained logk-values for some non-active organic substances in mixed binary solvents systems. It was studied the kind these correlations change with changing mobile phase compositions. The present paper is a certain aspect of new studies on possibilities of the use Thin-layer Chromato-graphy as a pilot technique for Liquid Column Chromatography (1,2). In a study on the optimization of chromatographic process it is necessary to define the correlations between R_M-values which characterize the retention in TLC and k′-values which characterize the retention in in LCC.

In the paper the changes of these correlations with the changes of mobile phase compositions are studied. The conformity between theoretical calculated and experimental obtained R_M-values of chromatographed substances for differemt mobile phase compositions are investigated. A good agreement between theoretical and experimental data makes possible to foresee on the basis of the correlations between log k′- and R_M-values the retention in column chromatography.     

RP TLC Evaluation of log P for Higher Fatty Acids,Hydroxy Acids and their Esters

JPC – Journal of Planar Chromatography – Modern TLC - Higher fatty acids, hydroxy fatty acids, and their esters have been separated by reversed-phase thin-layer chromatography with...     

Use of Two-Dimensional TLC to Identify Phenolic Acids in the Foliage and Fruit of Peucedanum tauricum Bieb.

JPC – Journal of Planar Chromatography – Modern TLC - Two-dimensional planar chromatography (2D TLC) on cellulose layers, solid phase extraction (SPE), and reversed-phase...     

应用量化参数和CoMFA法研究苯甲酸类化合物的结构和其pKa值的相关性

人工神经网;应用量化参数和CoMFA法研究苯甲酸类化合物的结构和其pKa值的相关性     

Determination of Selected Quinolones and Fluoroquinolones by Use of TLC

Abstract

There are many different methods of quinolones determination. The most often used method of quinolones analysis is liquid chromatography. In this work some selected quinolones (cinoxacin, pipemidic acid) and fluoroquinolones (ofloxacin, pefloxacin) were separated with thin-layer chromatography (TLC). The two different mobile phases were used as follows: buffer solution (pH = 5.5)-methanol, 40:10 (v/v) and acetonitrile-water-acetic acid, 6:40:4 (v/v/v), respectively, for quinolones and fluoroquinolones. The following chromatographic parameters were calculated for these separations: R_F, ?R_F, R_M, and R_S. The possibility of qualitative determination of cinoxacin, pipemidic acid, ofloxacin, and pefloxacin using TLC was shown.     

Use of Micelles in the TLC Separation of Polynuclear Aromatic Compounds and Amino Acids

Abstract

The polynuclear aromatic compounds (PNA): anthracene, napthalene, phenanthrene, pyrene, pyrenecarboxaldehyde, benzo (a) pyrene, benzo (e) pyrene, perylene and fluorene can be chromatographed on polyamide TLC sheets using an aqueous micellar solution cf sodium dodecylsulfate (SDS) as the mobile phase. Reversed micellar solutions (of sodium dioctylsulfosuccinate) were used in a reverse phase chromatographic separation of amino acids. Some amino acids tended to streak slightly rather than move as discrete spots. Conditions could be adjusted, however, so that most of the amino acids and all PNA's would move as spots.