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.     

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.     

Semi-Preparative High-Performance Liquid Chromatographic Separation of Potato Glycoalkaloids

Abstract

A semi-preparative high-performance liquid chromatographic method has been developed to separate crude mixtures of the potato glycoalkaloids α-chaconine, α-solanine, commersonine and demissine. Milligram quantities of each substance can be obtained within an 8 hour period. A Zorbax semi-preparative NH₂ column and a solvent system of tetrahydrofuran-water-acetonitrile (55:20:25) were employed for the separation. The flow rate was 1.0 ml/min. Glycoalkaloid separations were monitored using both refractive index and ultraviolet detection (215 nm). Further analyses of these glycoalkaloids were done using analytical high-performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) to check compound purity and identity.     

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.     

Development of Microwave-Assisted Extraction of Trigonelline Biomarker from Trigonella foenum-graecum Seeds Followed by High-Performance Thin-Layer Chromatographic and High-Performance Liquid Chromatographic Analyses

JPC – Journal of Planar Chromatography – Modern TLC - An efficient and fast microwave-assisted extraction (MAE) technique was developed for extracting trigonelline as an indicative...     

Micellar Electrokinetic Chromatography of Cephalosporin Antibiotics

A simple micellar electrokinetic chromatographic (MEKC) method is described for the simultaneous separation of twelve cephalosporin antibiotics. The separation was performed in a phosphate buffer (0.1 M, pH 6.6) with sodium dodecyl sulfate (SDS) (0.1 M) as an anionic surfactant. The complete separation of twelve cephalosporins was attained in 36 min. Application of the method to the quantitative analysis of cefuroxime, cephalexin, cephapirin and cephradine in pharmaceutical preparations was demonstrated.     

Comparative High-Performance Liquid Chromatographic and High-Performance Thin-Layer Chromatographic Study for the Simultaneous Determination of Dapagliflozin and Metformin Hydrochloride in Bulk and Pharmaceutical Formulation

JPC – Journal of Planar Chromatography – Modern TLC - The discovery of potent antidiabetic drugs is of necessity owing to the rapid prevalence of diabetes worldwide. The investigation...     

Separation of Ramipril Optical Isomers by High-Performance Liquid Chromatography

Abstract

High-performance liquid chromatographic methods for determining the optical purities of ramipril, a novel angiotensin converting enzyme inhibitor, and its synthetic intermediates have been developed. Analytical procedures were established for the resolution of optical isomers of two moieties, precursor I and precursor II, used for the preparation of ramipril. No occurrence of racemization during condensation reaction of the two precursors could be unambiguously confirmed by the proposed methods. On the basis of analytical data ramipril bulk material proved to be optically pure.     

A Simple Device for the Solute Elution from Thin-Layer Chromatographic Plates to High-Performance Liquid Chromatographic or Mass Spectrometric Instrument

JPC – Journal of Planar Chromatography – Modern TLC -     

Separation of Monosulfated Bile Acids by High-Performance Liquid Chromatography

Abstract

Separation of 3-, 7- and 12-monosulfates of cholate, chenodeoxycholate, deoxycholate, lithocholate and ursodeoxycholate and their glyco- and tauro-conjugates by high-performance liquid chromatography on a reversed phase column has been carried out. Effects of pH and salt concentration of a mobile phase on the k' value of sulfated bile acids were investigated with the μBondapak C₁₈ and ODS SC-02 columns. The 3-sulfated bile acids were efficiently separated on ODS SC-02 using three aqueous ammonium carbonate/acetonitrile systems. The chromatographic behaviors of 7-and 12-sulfated bile acids are also briefly discussed.     

High-Performance Thin-Layer Chromatographic Assessment of Thermally Modified Wood

JPC – Journal of Planar Chromatography – Modern TLC -     

Analysis of Bromo-DragonFLY by High-Performance Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC -     

High-Performance Thin-Layer Chromatographic Determination of Carbamate Residues in Vegetables

JPC – Journal of Planar Chromatography – Modern TLC - A high-performance thin-layer chromatographic method has been developed for determination of four carbamate residues in vegetables....     

High-Performance Thin-Layer Chromatographic Determination of Idebenone in Pharmaceutical Preparations

JPC – Journal of Planar Chromatography – Modern TLC - A high performance thin layer chromatographic method has been developed for the determination of idebenone in pharmaceutical...     

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...     

反相高效液相色谱对DABTH—氨基酸的分离与鉴定

应用反相高效液相色谱(RP-HPLC)技术,采用等度洗脱。对20种标准DABTH-氨基酸进行了分离与鉴定,灵敏度达到pmol水平;并以溶菌酶为模式蛋白,经手工DABITC/PITC双偶联方法对其N端部分序列进行Edman降解,其降解产物DABTH-氨基酸用RP-HPLC技术进行了鉴定,蛋白质微量序列分析的灵敏度达到nmol水平.     

High-Performance Thin-Layer Chromatographic Detection of Profenofos in Biological Materials

JPC – Journal of Planar Chromatography – Modern TLC -     

High-Performance Thin-Layer Chromatographic Detection of Endosulfan from Biological Samples

JPC – Journal of Planar Chromatography – Modern TLC -     

Thin-Layer Chromatographic Separation of the Chloroplast Pigments

Abstract

The separation of the chloroplast pigments is achieved by two-way chromatography on cellulose sheets. The chromatographic system employed is superior to any other thin-layer or paper system yet found.