Quantitative Structure—Retention Relationships of Some Steroid and Phenanthrene Derivatives on Cyano-, Reversed-Phase,and Normal-Phase Thin-Layer Chromatography Stationary Phases

JPC – Journal of Planar Chromatography – Modern TLC - In the presented study, quantitative structure—retention relationships (QSRR) methodology was used to investigate the...     

Study of the Chromatographic Behavior of Selected Steroid Hormones on Aluminum Oxide Plates Based on Quantitative Structure—Retention Relationships

JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic properties of eight steroids: trans-androsterone, methyltestosterone, testosterone, progesterone, cortisone,...     

Retention Time Locking in the Determination of Narcotic Drugs by Chromatography and Chromatography–Mass Spectrometry

The use of retention time locking (RTL) in the development of unified procedures for the detection and quantitative determination of drugs in biological fluids was considered. With consideration for the use of RTL, a chromatographic procedure with flame-ionization and mass-selective detection was developed for the detection and quantitative determination of opiates and their synthetic analogs; phenylalkylamine derivatives; cocaine; ketamine; and other narcotic drugs, their derivatives, and metabolites in urine. The analytical ranges for chromatography–mass spectrometry were 0.05–1000 and 0.005–1000 g/mL under the conditions of total ion current (TIC) scanning and selected ion monitoring (SIM), respectively. With flame-ionization detection (GC–FID), the analytical range was 0.5–1000 g/mL.     

Application of Two-Dimensional High-Performance Thin-Layer Chromatography to Qualitative and Quantitative Toxicological—Chemical Analysis

JPC – Journal of Planar Chromatography – Modern TLC - The present paper describes various application possibilities of high-performance thin-layer chromatography (HPTLC) for qualitative...     

Rapid Validated Thin-Layer Chromatography—Densitometry for the Simultaneous Determination of Three Co-formulated Drugs Used for Common Cold Treatment

JPC – Journal of Planar Chromatography – Modern TLC - A rapid validated thin-layer chromatography (TLC)—densitometric method has been developed for the simultaneous determination...     

Development and Validation of a High-Performance Thin-Layer Chromatography—Densitometry Method for the Quantitative Estimation of Morphine in the Classical Ayurvedic Formulation Kamini Vidrawan Ras

JPC – Journal of Planar Chromatography – Modern TLC - Kamini Vidrawan Ras is a classical Ayurvedic medicine, referred to in Bhaisjya Ratnavali, a book recognized by the Drugs and...     

Thin-Layer Chromatography—Densitometry and Thin-Layer Chromatography—Image Analysis for Screening Bile Acid-Binding Activities of Thai Edible Plants

JPC – Journal of Planar Chromatography – Modern TLC - Despite the fact that many researchers have developed different methods for the determination and detection of bile acid...     

Ultra-Thin Layer Chromatography (UTLC) — A New Dimension in Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - Miniaturization is general trend in modern analytical methods, with the main targets of increasing sensitivity, shortening analysis...     

The First Normal-Phase High-Performance Thin-Layer Chromatographic Method for the Simultaneous Determination of the Antimalarial Drugs Atovaquone and Proguanil from Malarone® Tablets

JPC – Journal of Planar Chromatography – Modern TLC -     

Quantitative Structure—Property Relationship on Prediction of Surface Tension of Nonionic Surfactants

When a surfactant is solved into a solvent, it will adsorb onto the surface of the solution and reduce the surface free energy to a marked degree. The surface free energy, which is the minimum amount of work required to create that surface, is usually measured by surface tension. The minimum of surface tension 0g is the most useful key for characterizing the activity of surfactant. It is well known that 0g is determined by the molecular structure of surfactant, i.e., the contributions from …     

Application of Thin-Layer Chromatography and Gas Chromatography—Mass Spectrometry for Evaluation of the Chemical Stability of Hexyl Nicotinate

JPC – Journal of Planar Chromatography – Modern TLC - In this study, thin-layer chromatography with densitometry and gas chromatography—mass spectrometry (GC—MS) were used...     

Determination of Fluoroquinolone Antibiotics in Industrial Wastewater by High-Pressure Liquid Chromatography and Thin-Layer Chromatography—Densitometric Methods

JPC – Journal of Planar Chromatography – Modern TLC - Two methods were described for the simultaneous determination of ciprofloxacin HCl (CIP) and moxifloxacin HCl (MOX) in their binary...     

Investigations of Retention Rule in Reversed-Phase High Performance Liquid Chromatography——Theoretical Consideration of Retention Convergence and Experimental Verification

This paper studied the effect of different chromatographic parameters in RP-HPLC (for example,composition of mobile phase, temperature, number of carbon atoms within the solute molecules, solvent molecules and alkyl ligand on bonded phase surface) on the retention convergence based on the displacement adsorption multi-interaction model,and derived a few retention convergent equations by using thermodynamic method,which have been verified by a great deal of experimental data of homologous series.Moreover,we have developed a general method, which can calculate the coordinate values of various retention convergent points by computer directly from experimental data,and the results predicted are in good agreement with that obtained by using plotting method.     

High-Performance Thin-Layer Chromatography and Indirect TLC—HRMS-Based Determination of 20-Hydroxyecdysone in Sesuvium portulacastrum

JPC – Journal of Planar Chromatography – Modern TLC - 20-Hydroxyecdysone (20E), an imperative phytoecdysteroid, regulates several biochemical and physiological processes during the...     

Thin-Layer Chromatography—Image Analysis Method for the Simultaneous Quantification of Andrographolide and Related Diterpenoids in Andrographis paniculata

JPC – Journal of Planar Chromatography – Modern TLC -     

Quantitative Structure—Activity Relationships in the Lithium and Sodium Affinities of n—Alkyl Fluorides

B3L YP/6-31 g(d,p)method was used to calculate the lithium and sodium affinities of n-alkyl fluoride. These affinities were found to obey the Holmes relationship, i.e.they correlate linearly with the quotient n/(n 1), where n is the number of carbon atoms in the alkyl chain. From the correlation the limiting values of lithium and sodium affinities for very long alkyl chain were predicted to be-153.3kJ/mol and -108.4kJ/mol,respectively.     

Effect of Micelle Composition on Acidic Drugs Separation Behavior by Micellar Electrokinetic Capillary Chromatography

Micellar electrokinetic capillary chromatography (MECC) is a branch of capillary electrophoretic techniques, in which surfactant micelles are added to the electrolyte solution as pseudostationary phase. Separation in MECC is based on electrophoretic mobilities of the analytes when partitioned into micelles1. In this work, four acidic drugs similar in structure with aryl carboxylic acid were separated by MECC. The effects of type of surfactant, such as anionic surfactant SDS, nonionic …     

Analysis of the Nucleoside Content of Cordyceps sinensis Using the Stepwise Gradient Elution Technique of Thin-Layer Chromatography

Nucleoside is the main class of active components in Cordyceps sinensis. Thin-layer chromatography (TLC) is one of the most commonly used methods in pharmacopoeias for analyzing chemical components of herbal medicine. Since the isocratic elution method cannot be applied successfully in TLC analysis for separating all the nucleoside components, the stepwise gradient elution has been developed in this work to separate eight nucleoside standards with success. In this way, quantitative analyses of the samples of Cordyceps sinensis were achieved via the proposed TLC procedure coupled with the scanning densitometric techniques of CAMAG and TLCQA methods for qualitative and quantitative analysis.