Silica gels thin-layer liquid

Ni et al. [143] investigated the profile of the major metabolites of primaquine produced by in vitro liver microsomal metabolism, with silica gel thin-layer and high performance liquid chromatography analysis. Results indicated that the liver microsomal metabolism could simultaneously produce both 5-hydroxyprimaquine (quinoline ring oxidation product) and carboxyprimaquine (side-chain oxidative deamination product). However, the quantitative comparative study of microsomal metabolism showed that the production of 5-hydroxyprimaquine was far much higher than that of carboxyprimaquine. 

Ni et al. [144] also investigated the profiles of major metabolites of primaquine produced from liver microsomal and mitochondrial metabolism, in vitro by silica gel thin-layer and reversed-phase high performance liquid chromatography. The results... 

Sauer and Fitzgerald [9] have described thin layer chromatographic technique for the identification of water-borne petroleum oils. Aromatic and polar compounds are removed from the sample by liquid-liquid extraction with acidified methanol, the extract is chromatographed on a silica gel thin layer plate, and the separated components are detected by their fluorescence under long- and short-wave ultraviolet light. Unsaturated non-fluorescing compounds are detected by iodine staining. 

Chemical stability studies are monitored by silica gel thin-layer chromatography (tic) or by high performance liquid chromatography (hplc) using a reverse- Ph ase Clg coated column (24). Hplc peaks or dc spots are visualized by their uv absorption at 245 nm the dc spots can also be detected by ceric sulfate or phosphomolybdic acid staining. 

Normal-phase liquid chromatography is thus a steric-selective separation method. The molecular properties of steric isomers are not easily obtained and the molecular properties of optical isomers estimated by computational chemical calculation are the same. Therefore, the development of prediction methods for retention times in normal-phase liquid chromatography is difficult compared with reversed-phase liquid chromatography, where the hydrophobicity of the molecule is the predominant determinant of retention differences. When the molecular structure is known, the separation conditions in normal-phase LC can be estimated from Table 1.1, and from the solvent selectivity. A small-scale thin-layer liquid chromatographic separation is often a good tool to find a suitable eluent. When a silica gel column is used, the formation of a monolayer of water on the surface of the silica gel is an important technique. A water-saturated very non-polar solvent should be used as the base solvent, such as water-saturated w-hexane or isooctane. 

Normal-phase column liquid chromatography using unmodified silica gels has been used for the purification of both natural and synthetic compounds. It is a powerful tool for stereoisomer separations. The instability of unmodified silica gel means that its use for quantitative analysis in column liquid chromatography is avoided because of poor reproducibility. Normal-phase separation has, however, been performed using thin-layer liquid... 

Olefins, sultones, alkanes, and alkenesulfonates may be separated by liquid chromatography on silica gel using hexane, trichloromethane-hexane, ethanol-dime thy lcarbonate, and ethanol-ammonium hydroxide as the eluents. Pueschel and Prescher [110] achieved the separation of alkene-1,4-sultone and alkene-1,3-sultone from each other and from other sulfonic acid esters in AOS by thin-layer chromatography on silica gel G with 4 1 diethylcarbonate-ligroine as the... 

Tswett s initial column liquid chromatography method was developed, tested, and applied in two parallel modes, liquid-solid adsorption and liquid-liquid partition. Adsorption ehromatography, based on a purely physical principle of adsorption, eonsiderably outperformed its partition counterpart with mechanically coated stationary phases to become the most important liquid chromatographic method. This remains true today in thin-layer chromatography (TLC), for which silica gel is by far the major stationary phase. In column chromatography, however, reversed-phase liquid ehromatography using chemically bonded stationary phases is the most popular method. 

Thin layer chromatography (TLC) Solid (silica gel) Liquid (solvent, often a mixture). Also called developer. 

The soluble metabolites excreted from animals dosed by injection were collected on AmberliteR XAD-4 resin, the resin eluted sequentially with diethyl ether, acetone, and methanol, and the solutes separated by thin-layer chromatography on silica gel and quantitated by liquid scintillation counting. 

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