Selection of Adsorbents for the Separation of Chlorophylls

Abstract

Selection of adsorbents for the separation of chlorophylls has been conventionally attempted. It has been confirmed that Sepharose CL-6B is the best adsorbent for separation of chlorophylls among the adsorbents tested in the present study.     

Ligand-Exchange Chromatography of Nucleosides,Nucleic Acid Bases and Amines of Copper(II) Glyoximated-Lycopodium Clavatum with Refractive Index Detection

Abstract

Ligand-exchange separation of nucleosides, nucleic acid bases and amines has been studied by using a new exchanger obtained by functionalyzing Lycopodium Clavatum with glyoxime.

This study shows that 1igand-exchange chromatography with glyoximated-lycopodium clavatum can provide new opportunities for the rapid separation of ligands.     

Computer Enhanced Spectroscopic Separation of Coeluted Components in Supercritical Fluid Chromatography Coupled with an Ultraviolet Multichannel Detector

Abstract

Computer enhanced spectroscopic separation technique has been applied to identification of coeluted components in supercritical fluid chromatography by using an ultraviolet photodiode array multichannel detector. The powerful function such as peak deconvolution procedure has successfully offered thespectroscopic complete separation for even partially or completely coeluted components in super critical fluid chromatography.     

Optimization of Solvent Mixture Compositions for High Speed Countercurrent Distribution

Abstract

Seven solvents considered appropriate for use with relatively sensitive biosynthetic products undergoing separation by multilayer coil planet centrifuge high speed countercurrent distribution (HSCCD) have been evaluated in a new and systematic procedure for optimal solvent selection. the new method was illustrated by a complete HSCCD separation of five closely related dipeptides.     

Chromatographic Separation of Closely Related Dyes on Metal Salt-Impregnated Thin Layers

Abstract

The chromatographic characteristics of 42 dyes belonging to different groups have been studied on metal salt-impregnated plates. A suitable separation scheme for the dyes studied and suitable adsorbent system as well as solvent system have been developed.     

Class Fractionation of Acidic Glycolipids and Further Separation of Gangliosides by OPTLC

Abstract

The use of the OPTLC method has been extended to the separation of the acidic fraction of the total lipid extract derived from a given blood element. This newly developed method is suitable for the interclass separation of sulphatides and gangliosides and further intraclass separation of gangliosides on the same TLC plate with step gradient development. The elutions can be performed on 10 × 10 cm (or larger) HPTLC plates with 13 parallels on each one. The chromatograms were stained either with orcinol-H₂SO₄ to show class separation (in this case only a single isocratic elution was performed) or with rescrcinol-HCl reagent to visualize the ganglioside intraclass separation. The chromatograms were evaluated by spectrodensitometric scanning and the reproducibility of the separation was determined.     

Application of Computer-Assisted 13C NMR Spectrometry for Separation and Determination of Heptane Isomers in the Feed Stocks of Cyclohexane Used in Purification Process

Abstract

A computer-assisted ¹³C NMR spectrometric method for separation, identification and quantitative determination of C₇ hydrocarbons in cyclohexane has been developed. A simulated library containing chemical shift and multiplicity data of 131 compounds of C₇ hydrocarbons has been prepared. The method incorporates the unique features of quantitative and edited ¹³C NMR spectra for separation and identification of mixture of hydrocarbons. It serves as an alternative method to GC-MS for monitoring the composition of feed stocks used for cyclohexane purification process.     

RP-HPLC and NMR study of antioxidant flavonoids in extract from <Emphasis Type="Italic">Gentiana piasezkii</Emphasis>

A reversed-phase high performance liquid chromatography (RP-HPLC) separation with photodiode array detection (PDA) was developed for the simultaneous determination of five flavonoids, lutonarin (LO), saponarin (SA), isoorient (IO), 7-O-feruloylorientin (FO) and luteolin (LE) in the extract of Gentiana piasezkii, a popular forage grass, pharmaceutical and ornamental plant in China. The optimized method was achieved for the separation and detection of selected constituents, using acetonitrile-1% acetic acid as the mobile phase with gradient elution at a flow rate of 0.8 mL/min and 350 nm as the detection wavelength. The contents of the five flavonoids, i.e., LO, SA, IO, FO and LE in the plant of G. piasezkii were 0.1524, 0.0673, 0.300, 0.0552 and 0.0052%, respectively. The compounds possess similar structures and have been studied by nuclear magnetic resonance (NMR) spectroscopy.     

Operation of an Improved,Continuous Annular Chromatograph

Abstract

A rotating annular chromatograph has been demonstrated to have utility in the continuous separation of solutes in a feed stream. Recent modifications to the system have resulted in a more efficient separation. Design of the inlet and the exit has been significantly changed to improve chromatograph performance. Refinements have also been made to the method of gradient elution. The effects of changing superficial velocity and initial resin loading on the height equivalent to a theoretical plate are shown for the ternary nickel-cobalt carbonate amine system. A continuous separation of this ternary mixture utilizing pH gradient elution is presented.     

HPLC Separation of Taxol and Cephalomannine

Abstract

Taxol [1], a highly functionalized antimitotic diterpene which occurs as a minor component of extracts of the bark from trees of the genus Taxus, is required in increasingly larger quantities for clinical trials. Final purification of taxol requires separation from cephalomannine [2]. an efficient separation of those closely related analogs has been achieved by normal phase HPLC on a cyanopropyl column.     

A Simple Liquid Chromatographic Method for Analysis and Isolation of the Unsaturated Components of Anacardic Acid

Abstract

Good analytical and preparative separation of the saturated, monoene, diene and triene components of anacardic acid have been achieved by reverse phase HPLC on a C₁₈ column by isocratic elution with methanol-aqueous acetic acid.     

Routine Preparative HPLC of Aromatic Silyl Compounds on Caffeine Coated on Silica Gel

Abstract

A liquid chromatographic method using caffeine coated on silica gel, for separation and purification of acenaphthenylsilyl compounds is described. This has been achieved on a preparative scale.     

Separation Studies of Metal Ions in Sodium Thioglycolate Medium by Thin Layer Partition Chromatography

Abstract

A thin layer partition chromatographic method has been developed for separation of Fe(III), Ni(II), Zn(II), Cu(II), Pb(II) and Mn(II) on thin layers of silica gel-G as an adsorbent. The R_f values were determined using 0.01–0.2 aqueous solution of sodium thioglycolate as a mobile phase. The dependence of R_f values on the migration time, pH and concentration of mobile phase has been studied. The optimum conditions for possible 3-component separation have been determined. Metal ions have been separated, detected, eluted and quantitatively determined by atomic absorption spectroscopy. The present method was applied to the separation and determination of zinc in forensic samples.     

A review of: “HPLC of Biological Compounds-A Laboratory Guide,by William S. Hancock & James T. Sparrow, (Volume 26 of the Chromatographic Science Series,Jack Cazes,Editor), Marcel Dekker,Inc., New York,NY, 1984, 361 pp., £39.75 (US)”.

Abstract

The analytical and preparative separation of the saturated, monoene, diene and triene constituents of cardanol and cardol have been achieved by reverse phase HPLC on a C₁₈ column using gradient elution.     

TLC Separations of Some Closely Related 3-Hydroxy-6H-Benzofuro [2, 3-C] [1] Benzopyran-6 -Ones and Their Basic Ethers

Abstract

During the present study, the TLC separation of some closely related 3-hydroxy-6H-benzofuro [2, 3-C] [1] benzopyran-6-ones and their basic ethers have been carried out.     

A 13-membered crown ether with an azoxy subunit in the macrocycle: Synthesis and X-ray structure

The presented azoxy compound is an example of a new crown ether analogue. It has been synthesized by the reduction of an open chain dinitro compound with stannite under strongly alkaline conditions. A method for the separation of the azo and azoxy compounds formed simultaneously has been proposed. The structures of two crystallographically independent molecules of compound2 have been determined. In spite of the small size of the macroring in compound2, the phenyl residues around the azoxy group have atrans orientation. Supplementary Data relating to this article have been deposited with the British Library as Supplementary Publication No. 82157 (11 pages).     

Selective Extraction of Tungsten(VI) with 4-methyl-2-pentanol from Hydrochloric Acid Media

Abstract

A new and rapid method has been developed for the extractive separation of tungsten from hydrochloric acid media. Various relevant factors such as effects of acid concentration, solvent concentration, salting-out agent and diverse ions have been critically studied and discussed. The method has also been successfully applied to analysis of steel alloy.     

Ion Exchange High Performance Liquid Chromatography of Leukotrienes

Abstract

A novel anion exchange liquid chromatographic system has been developed for isocratic separation of leukotrienes. Hydrophobic as well as ionic forces were found to influence the separation. By optimization of solvent strenght, ionic strenght and pH, amphoteric peptidoleukotrienes could be separated simultaneously with hydroxy fatty acids such as leukotriene B₄ and its ω-oxidized metabolites. To obtain a good buffering capacity of the mobile phase at optimum pH, a multicomponent buffer was developed.     

Synthetic Inorganic Ion-Exchangers XV. Thin-Layer Chromatography of Metal Ions on Thorium Tungstate: Quantitative Separation of Hg(II) from Several Other Metal Ions

Abstract

The analytical application of Thorium tungstate as an ion exchanger has been explored by thin-layer chromatographic (TLC) technique. Binder-free thin layers of thorium tungstate have been employed for some important binary and ternary separations. Quantitative separation of Hg(II) from the mixture of several other metal ions has been achieved.     

Thin-Layer Chromatography of Bile Alcohols,Bile Acids and Conjugated Bile Acids

Abstract

Thin-layer chromatography of bile alcohols, bile acids and bile acid conjugates has been reviewed. Particular emphasis has been placed on the separation of the glycine and taurine conjugated bile acids as a class and as individual compounds, and on the isolation of bile alcohols and C₂₇ bile acids diastereo-isomeric at C-25.