Association of HLA-B27 with ankylosing spondylitis.
Explore the source record for details and available documents.
Back Pain↗
Biomedical subjects
R Bhushan
Publications and source records attributed to R Bhushan.
A comparative study of HPLC and TLC separation of amino acids using Cu(II) ion.
Separation of amino acids using Cu(II) by RP-HPLC and impregnated TLC is reported. For HPLC the sample mixture of amino acids containing copper (II) was injected into the column while for TLC the silica gel plates were impregnated with Cu(II). The mobile phase used in HPLC was acetate buffer (0.3 M, pH 6.0)-acetonitrile (9:1, v/v), and that in TLC was acetate buffer (0.3 M, pH 6.0):acetonitrile-n-butanol (12:5:10, by vol.). The results have been compared and discussed.
Amino Acids↗
Separation and identification of some cephalosporins on impregnated TLC plates.
Ethylenediamine tetra-acetic acid disodium salt dihydrate was used as an impregnating reagent to resolve some cephalosporins. Both changes in the concentration of the impregnating reagent and in the composition of the mobile phase influenced the resolution. Three new solvent systems (I) propionic acid:2-propanol:water (6:3:3, v/v/v), (II) 2-prapanol:water:ethyl acetate (5:3:3, v/v/v) and (III) n-butanol:water:acetic acid (5:4:2, v/v/v) were found to be successful.
Cefaclor↗
TLC separation of some common sugars on silica gel plates impregnated with transition metal ions.
TLC separation of glucose, maltose, lactose, sorbitol and sucrose on silica gel plates impregnated with transition metal ions, Cu(II), NI(II), Zn(II) or Cd(II), has been achieved. The identification is very distinct by using KMnO4 (0.5%) in 0.1 M NaOH as the spray reagent. Two new solvent systems, (A) n-PrOH-H2O) (8:4, v/v), and (B) i-PrOH-H2O (8:4, v/v), were worked out.
Cadmium↗
Accumulation pattern of pesticides in tropical fresh waters.
High-performance liquid chromatography has been used to study the persistence of commonly used organophosphorus and carbamate pesticides-carbaryl, carbendazim, carbofuran, dimethoate, malathion and methyl parathion in river water in the presence of bottom sediment in laboratory aquaria. The fate of pesticides in water and sediment in pre- and post-monsoon water from three sources has been compared. It has been established that rapid degradation occurs once the pesticide leaches into sediment from water. Degradation was at a much faster rate in post-monsoon water and sediment. It was found that pH and organic matter content affect rate of decay.
Antinematodal Agents↗
Direct resolution of enantiomers by impregnated TLC.
Direct resolution of enantiomers has acquired greater analytical importance. Of various chromatographic techniques, TLC continues to enjoy considerable reputation for the purpose. The present paper deals with an important and yet less explored aspect of TLC i.e. impregnation. Methods of impregnation of thin layer material with a variety of reagents and the role of impregnating reagents in resolving compounds on these layers, with special reference to main/basic approaches of impregnation as applied to direct enantiomeric resolution, are discussed.
Amino Acids↗
TLC resolution of enantiomers of amino acids and dansyl derivatives using (1R,3R,5R)-2-azabicyclo[3,3,0]octan-3-carboxylic acid as impregnating reagent.
The enantiomeric resolution of certain amino acids and some of their dansyl derivatives was achieved on thin silica gel plates impregnated with (1R,3R,5R)- 2-Azabicyclo[3,3,0]octan-3-carboxylic acid, which is an industrial waste material, and a proline analogue non proteinogenic alpha-amino acid. Different combination of 0.5 M NaCl-MeCN were found to be successful in resolving dansyl-DL-amino acids; addition of methanol was required in some cases. Spots were visualised using a fixed wavelength (254 nm) ultraviolet chamber. Resolution of DL-amino acids was successful in different combinations of MeCN-MeOH-H2O and detection was made with ninhydrin (0.2% in acetone).
Amino Acids↗
Resolution of enantiomers of ibuprofen by liquid chromatography: a review.
Ibuprofen is one of the most effective and widely used non-steroidal analgesic and anti-inflammatory agent. It is marketed as a racemic mixture though it is known that the pharmacological activity resides in the (S)-(+)-enantiomer only. Several direct/indirect liquid chromatographic methods involving a variety of chiral/achiral phases along with their possible role in resolution, chiral and achiral agents used for derivatisation have been discussed with special reference to ibuprofen, and mentioning their application to the resolution of other 2-aryl-propionic acids/profens.
Anti-Inflammatory Agents, Non-Steroidal↗
Liquid chromatographic separation of some PTH-amino acids.
Liquid chromatographic studies on the separation of ten PTH-amino acids were carried out using normal phase untreated silica gel plates, C-18 RP precoated plates and RP-HPLC. Resolution of a complex mixture of PTH-amino acids was achieved using all the three types. Certain new successful solvent systems have been worked out in each case. HPLC was carried out with Lichrosphere 100 RP-18 (5 microns) column. Acetonitrile and sodium acetate buffer of pH 4.0 was used for reversed phase chromatography while for normal phase TLC combinations of chloroform-acetonitrile and chloroform-tetrahydrofuran were applied.
Amino Acids↗
TLC separation of certain tetracycline and amino glycopeptide antibiotics.
The separation of tetracycline and amino glycopeptide antibiotics was achieved on silica gel thin layers. Tetracycline antibiotics were resolved on a Co+2 (1.0%) impregnated silica gel layer using ethanol:acetic acid:water (10:6:6, v/v/v) as the mobile phase. Amino glycopeptide antibiotics were separated on an untreated silica gel layer using the mobile phase n-butanol:formic acid:water (6:5:7, v/v/v). The spots of these antibiotics were located by exposing the chromatoplate to iodine vapours.
Anti-Bacterial Agents↗
Resolution of enantiomers of amino acids by HPLC.
Application of HPLC as a prime tool in the area of enantiomeric resolution has opened doors of success and varied interest. Use of chiral reagents either indirectly (as derivatization reagent) or directly (added to stationary or mobile phase) has led to achieve resolution of a wide range of compounds. Amino acids, being important molecules with simple structure and easy availability, have been extensively studied. A bibliographic survey on HPLC resolution of amino acids and derivatives along with a brief discussion on general methods of enantiomeric separation has been presented.
Amino Acids↗
Improved thin layer chromatographic resolution of PTH amino acids with some new solvent systems.
Three new solvent systems, pyridine: benzene (2.5:20, v/v), methanol:carbon tetrachloride (1:20, v/v) and acetone:dichloromethane (0.3:8, v/v), for the resolution of a mixture of 18 PTH amino acids have been reported. Using these solvent systems, various combinations of PTH amino acids which had previously posed resolution problems have been resolved and identified.
Acetone↗
Simultaneous determination of a mixture of organophosphorus and carbamate pesticides by high performance liquid chromatography.
A simple HPLC procedure has been developed for the simultaneous determination of a mixture of standard carbaryl, carbofuran, carbendazim, dimethoate, malathion and methyl parathion from a spiked agricultural soil sample. The pesticide mixture has been extracted using methanol-water. A concave gradient elution with acetonitrile-phosphate buffer for 15 min followed by linear elution for 5 min, using a wavelength of 224 nm for detection, has been found to resolve the mixture efficiently.
Benzimidazoles↗
Separation of vitamin B complex and folic acid using TLC plates impregnated with some transition metal ions.
The separation of Vitamin B complex and folic acid was achieved on silica gel layers impregnated with Mn++, Fe++, Co++, Ni++, Cu++, Cd++, Zn++, or Mg++ (0.1%, 0.2%, 0.3%, 0.4% of each ion). Three new solvent systems n-propanol: n-butanol:water:ammonia (7:5:1:2, by vol), n-propanol:n-butanol:water:ammonia (7:5:1:1.5, by vol), n-propanol:n-butanol:water:ammonia (7:5:0.75:2, by vol) were developed. The spots of vitamins were located by exposing the chromatoplate to iodine vapours.
Chromatography, Thin Layer↗
TLC studies on certain aminoglycoside antibiotics.
Aminoglycoside antibiotics were separated by thin layer chromatography. Separation was achieved on untreated silica gel layers using various combinations of solvent systems, dioxane:ammonia, methanol:ammonia and propanol:ammonia. These antibiotics were visualized with the help of iodine vapours.
1-Propanol↗
Degradation of organophosphorus and carbamate pesticides in soils--HPLC determination.
Best conditions suited for the extraction and trace analysis of dimethoate, malathion, methyl-parathion, carbaryl, carbendazim and carbofuran in soils, using HPLC, were established. This was followed by studies related to persistence of residues in different soils. Half-life and time taken for 95% dissipation were determined in each case. Higher pH, moderate moisture and high calcium carbonate content aided degradation while organic matter increased persistence.
Biodegradation, Environmental↗