Ion-Pair Reversed-Phase Thin-Layer Chromatography and High-Performance Liquid Chromatography of Benzoic Acids

The separation of benzoic acids by ion-pair reversed-phase thin-layer chromatography and high-performance liquid chromatography was studied. In the optimization of separation conditions, the effect of the nature and concentration of the organic solvent, acidity of the mobile phase, concentration of salts of quaternary ammonium bases, and the length of their hydrocarbon radical on the retention of benzoic acids was studied. Conditions of the separation of a mixture of benzoic, hydroxybenzoic, aminobenzoic, and nitrobenzoic acids on Silufol plates impregnated with cetyltrimethylammonium bromide were selected; the mobile phase was isopropanol–ammonium acetate buffer solution with pH 5–dodecyltrimethylammonium bromide.     

High-Performance Thin-Layer Chromatography and Reversed-Phase High-Performance Liquid Chromatography Methods for Fingerprinting of Salvadora persica Root Powder Extract Using Benzyl Isothiocyanate as Biomarker

JPC – Journal of Planar Chromatography – Modern TLC - Salvadora persica plant having a number of antimicrobial substances and the roots of the S. persica shrub have been demonstrated to...     

Application of Thin-Layer Chromatography to Evaluate the Lipophilicity of 5,8-Quinolinedione Compounds

JPC – Journal of Planar Chromatography – Modern TLC - Lipophilicity is a very important property while designing new drugs. Its influence on the pharmacological responses of compounds...     

Quantitative Analysis and Chromatographic Fingerprinting of WeiChangShu Tablet Using High-Performance Liquid Chromatography Combined with Chemometric Methods

WeiChangShu tablet is used for the treatment of gastrointestinal motility disorders for more than 10 years. However, no quality control method for this formulation has been established. Hence, it is important to establish a simple and effective method for chromatographic fingerprinting and quantitative analysis to assess the quality of WeiChangShu tablet. In this study, a high-performance liquid chromatography method was developed to obtain a fingerprint chromatogram, and to simultaneously determine 11 indexes including hydroxypaeoniflorin, albiflorin, peoniflorin, benzoylpaeoniflorin, rhein, aloeemodin, physcion, emodin, chrysophanol, liquiritin, and glycyrrhizinic acid. After the methodology validation, the chromatographic fingerprints and the contents of 11 compounds in 10 samples were obtained successfully to evaluate the uniformity of the quality of WeiChangShu tablet. Three chemometric methods including similarity analysis, principal component analysis and hierarchical cluster analysis were applied to classify and differentiate the different samples, and to evaluate the consistency of 10 samples of WeiChangShu tablet. A similar division was observed for 10 samples, and they were divided into three groups: group 1 (S1, S2), group 2 (S6–S9), and group 3 (S3–S5, S10). These results demonstrated that the developed method was suitable for the quality evaluation of WeiChangShu tablet.     

Determination of Carbonyl Compounds by High-Performance Liquid Chromatography

Carbonyl compounds in the form of 2,4-dinitrophenylhydrazones in alcoholic solutions were analyzed by high-performance liquid chromatography. This simple procedure is characterized by high sensitivity and reproducibility.     

Estimation of Alprazolam and Sertraline in Pure Powder and Tablet Formulations by High-Performance Liquid Chromatography and High-Performance Thin-Layer Chromatography

Abstract

This article describes validated high-performance liquid chromatographic (HPLC) and high-performance thin-layer chromatographic (HPTLC) methods for simultaneous estimation of alprazolam (ALZ) and sertraline (SER) in pure powder and tablet formulation. The HPLC separation was achieved on a Nucleosil C18 column (150 mm long, 4.6 mm i.d., and 5-µm particle size) using acetonitrile and phosphate buffer (50 + 50 v/v), pH 5.5, as the mobile phase at a flow rate of 1.0 mL/min at ambient temperature. The HPTLC separation was achieved on an aluminum-backed layer of silica gel 60 F₂₅₄ using acetone/toluene/ammonia (6.0:3.0:1.0, v/v/v) as the mobile phase. Quantification with the HPLC method was achieved with ultraviolet (UV) detection at 230 nm over the concentration range 3–18 µg/mL for both drugs with mean recovery of 101.86 ± 0.21 and 100.57 ± 0.31% for ALZ and SER, respectively. Quantification in HPTLC was achieved with UV detection at 230 nm over the concentration range of 400–1400 ng/spot for both drugs with mean recoveries of 101.32 ± 0.15 and 100.38 ± 0.51% for ALZ and SER, respectively. These methods are rapid, simple, precise, sensitive, and are applicable for the simultaneous determination of ALZ and SER in pure powder and formulations.     

Reversed-Phase Systems for the Separation of Coumarins and Furocoumarins by Thin-Layer and High-Performance Liquid Chromatography

Abstract

The retention behaviour of eleven derivatives of counarin was investigated by reversed-phase (RP) thin-layer and high performance liquid chromatography. The linear relationships between log k'or R_M values and the content of organic modifier in the aqueous mobile phase obtained for wide composition ranges indicate that the plots can be used to determine R_Mw and log k_w values by extrapolation to pure water. The effects of individual substituants on the retention and the correlation between TLC and HPLC data was analysed.     

Determination of Diketopiperazine Alkaloids of the Roquefortine Group by UV Spectroscopy, Thin-Layer Chromatography, and High-Performance Liquid Chromatography

Electronic absorption spectra and the chromatographic retention of six alkaloids from the roquefortine group under conditions of thin-layer chromatography and high-performance liquid chromatography were examined. The applicability of these techniques to the identification of diketopiperazine alkaloids in culture liquid extracts was demonstrated using the fungusPenicillium chrysogenumVKM F-1987 as an example.     

Determination of Tetracycline and Related Compounds by High-Performance Liquid Chromatography

Abstract

An isocratic high-performance liquid chromatography method for the determination of tetracycline and its related compounds is described. The method uses a reverse phase (C₁₈) column, a modified acetonitrile/water mobile phase, and banzoic acid as the internal standard. Elution of all compounds of interest is complete within seven minutes. Results are presented for thirteen commercial capsule formulations and are compared with results by microbiological assay and thin-layer chromatographic methods.     

The use of High-Performance Liquid Chromatography for the Speciation of Organotin Compounds

This review of the use of high-performance liquid chromatography (HPLC) for the speciation of organotin compounds which are primarily of significance in the marine environment is divided into sections on the basis of the different HPLC modes of separation. However, it should be noted that such a classification does not exist in reality. For instance, in an ion-pair reversed-phase system the separation mechanism for the ionic solutes may be ion-pair partitioning, or ion exchange, or both. The relevant practical information (e.g. column type, mobile phase, method of detection and detection limit) is presented in tabular form. A brief overview of the reported detection methods is included, because the delay in development of an easily interfaced, specific and sensitive detector has hindered the use of HPLC for organotin speciation studies. The literature reviewed covers publications from 1977, the year of the first application of HPLC to organotin speciation, to April 1995.     

Application of Thin-Layer Chromatography to High-Performance Liquid Chromatographic Separation of Steroidal Hormones and Cephalosporin Antibiotics

Abstract

High-performance liquid chromatographic (HPLC) separation of steroidal hormones and cephalosporin antibiotics was investigated by adsorption chromatography and reversed-phase chromatography, respectively.

Prior to the HPLC separation of these pharmaceuticals, silica gel thin-layer adsorption chromatography of steroidal hormones and reversed-phase thin-layer partition chromatography of cephalosporin antibiotics with chemically bonded dimethylsilyl silica gel were performed in order to obtain suitable HPLC separation systems.

In the separation of steroidal hormones, the same binary mobile phase ratios of TLC did not give satisfactory results in HPLC. For the sharp separation in HPLC, solvent strength in the binary solvent mixture used for TLC had to be decreased.

The difference in solvent strength for efficient separation between TLC and HPLC might be attributed to the fact that in HPLC the solvent elution power acts in an isocratic manner while in TLC it acts in a gradient manner.

On the other hand, a correlation of mobility between TLC and HPLC separation for cephalosporin antibiotics was obtained, and the possibility of direct transfer of chromatographic systems from TLC to HPLC for separation of these antibiotics was confirmed.     

Identification of 11 Marker Compounds Simultaneously in Herb Lancea tibetica by Using High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatography (HPTLC) method was developed for simple and rapid chemical analysis of Lancea tibetica...     

Simultaneous Determination of Carbinoxamine,Pholcodine, and Ephedrine in Antitussive Preparation by High-Performance Liquid Chromatography and Thin-Layer Chromatography-Densitometry

JPC – Journal of Planar Chromatography – Modern TLC - Simple, accurate, precise, sensitive, and validated high-performance liquid chromatography (HPLC) and thin-layer chromatography...     

Quantitative Analysis of Pentalgin ICN Tablets by Gradient and Isocratic High-Performance Liquid Chromatography

Two procedures were proposed for determining analgin (dipyrone), paracetamol, caffeine, phenobarbital, and codeine in the multicomponent drug Pentalgin ICN with the use of HPLC in gradient and isocratic modes. In the gradient version, columns packed with Nucleosil 100 C18 or Nova-Pak C18 adsorbents were used; at the initial stage, an acetonitrile-water mixture was used as an eluant, and a 0.025 M KH₂PO₄ solution was introduced as a mobile phase constituent after the emergence of all peaks other than that of codeine or immediately after the emergence of the analgin peak. In the isocratic version, a Nova-Pak CN HP column was used; a 1% KH₂PO₄ solution containing 5 vol % acetonitrile was an eluant. The detector wavelength was 212 nm. The separation time was shorter than 10 min (mobile-phase flow rate of 1 mL/min). Model solutions containing all active components and additives of the tablets were analyzed, and the performance characteristics of both procedures were calculated. The procedures ensure reliable analytical results; however, the isocratic version is technically simpler and more preferable for product control in commercial manufacture.     

Simultaneous Determination of Pioglitazone and Glimepiride by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC -     

Analysis of Triorganotin Compounds by High-Performance Liquid Chromatography with Reverse-Pulse Amperometric Detection

High-performance liquid chromatography (HPLC) coupled with the reverse-pulse amperometric (RPA) detection method has been developed for the analysis of triorganotin compounds in aqueous solutions. The major advantage of RPA vs. conventional amperometric detection is its ‘in situ’ elimination of interference from dissolved oxygen in the chromatographic eluent; therefore, no extra chemicals or apparatus are required for oxygen removal. With a Partisil-10 SCX column and an eluent of methanol/0.01 M sodium acetate buffer (70:30, pH 5.5), the four triorganotins, viz., trimethyl-, triethyl-, tripropyl-, and tributyltin, can be totally separated. Detection by RPA was performed with a static dropping mercury electrode with an initial potential of ?1.15 V and a final potential of +0.15 V. The absolute detection limit (S/N = 3) ranged from 12 ng of tributyltin (as tin) to 0.3 μg of trimethyltin (as tin). Applications of the method to the analysis of trace tributyltin in marine antifoulant leachate and sea water are described.     

High-Performance Thin-Layer Chromatography Analysis of Saccharin in Foods and Beverages

JPC – Journal of Planar Chromatography – Modern TLC - A simple, accurate, and inexpensive high-performance thin-layer chromatography (HPTLC) method has been established for analysis of...     

Determination of Nitidine Chloride in Toothpaste by Dual Gradient Two-Dimensional High-Performance Liquid Chromatography

Nitidine chloride in toothpaste was determined by two-dimensional high-performance liquid chromatography. One gradient pump was used to enrich and purify the sample. The analyte was passed into the analytical column by switching a valve following the removal of the sample matrix. The samples were extracted by ultrasonic extraction. A C₁₈ (2.1 mm × 100 mm, 5 µm) column was used in one dimension, and a second C₁₈ (4.6 mm × 250 mm, 5 µm) column was used in the other dimension. The mobile phase was 0.02 mol/L monobasic potassium phosphate and acetonitrile with double isocratic elution. The wavelength of the ultraviolet-visible detector was 328 nm. The linear range for nitidine chloride was between 0.01 and 2 mg/L, with a correlation coefficient greater than 0.9998. The limit of detection for nitidine chloride was 0.01 mg/kg. The mean recoveries were 88.7% to 91.0%, and the relative standard deviation was less than 2.81%. This method is simple, sensitive, and accurate for the determination of nitidine chloride in toothpaste.     

Assessment of Environmental Quantitative Variation of Diosgenin in Fenugreek Seeds via High-Performance Thin-Layer Chromatography Method

JPC – Journal of Planar Chromatography – Modern TLC - Fenugreek is one of the oldest medicinal plants known by mankind. The aim of this study is to evaluate the effect of environmental...     

Quantification of Dopamine in Portulaca oleracea Linn,by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A sensitive and accurate high-performance thin-layer chromatographic method has been developed, validated, and used for...