Thin-layer chromatography eluant

Salicylic acid and Its metabolite were separated by two methods. The first was thin layer chromatography on cellulose with BAW solvent as for the In vivo metabolism studies. A quicker separation was achieved with a polyamide column. The entire 400 pL from an individual assay was placed on top of a 0.8 x 2.0 cm column packed with Polyamide-6 (Accurate Chemical and Scientific Corp.). The salicylic acid metabolite was eluted with 6 mL water but salicylic acid was retained. 3a70B scintillation fluid (Research Product International Corp.) was used to determine the radioactive content of the entire 6 mL of eluant. Separation of salicylic acid and its metabolite by polyamide column chromatography was verified by thin layer chromatography. 

The amount of Na[Ph2CO] solution required depends on how dry the reaction mixture is. When the reaction appears visually to be complete, a small aliquot should be examined (solution IR spectrum) to ensure that the precursor cluster complex has reacted completely [using the 2096 cm-1 v(CO) band of Ru3(CO)j j(PMe2Ph)]. Alternatively, the progress of the reaction may be monitored by TLC (thin layer chromatography) (silica gel, petroleum ether eluant). 

The solution is evaporated to dryness under reduced pressure and the residue is purified by thin layer chromatography (PF-254G silica gel with 1 4 dichloromethane-hexane eluant). Three yellow bands are eluted. The second band is removed and product extracted from it is recrystallized from hexane. Yield 0.12-0.15 g (30-33%) of the desired product. Checkers used column chromatography (35 x 3-cm column, Silica Gel 60, 70-230mesh, Merck) to give the product as the second band when eluting with 1 4 dichloromethane-hexane. 

The filtrate obtained from this reaction mixture is reduced to a volume of 15.0mL in a rotating evaporator and purified by means of thin layer chromatography (TLC) preparative plates of 1-mm thickness (Kieselgel P. F. Merck) eluant diethyl ether (5% vol) in light petroleum ether. The dark brown band of the complex is eluted with dry diethyl ether (peroxide-free). 

The submitters purified the product by medium pressure liquid chromatography on a 60-cm x 5-cm column packed with 230-400 mesh silica gel 60 purchased from E. Merck. Ethyl acetate was used as eluant at a flow rate of 4 0 mL per min. Fractions (20 mL) were collected and analyzed by thin layer cHromatography. 

Silica gel (200 g, 60-200 mesh) was used as the adsorbent. The eluant was monitored by thin-layer chromatography with collection of only the first eluted component. 

The resulting samples from these two techniques were found to be identical from their elemental analyses, melting points (DISPIRO 3 and DISPIRO 4 were higher than 280 °C (decomposed)) and IR spectra. The yields were about 60%. Thin-layer chromatography gives Rf values of 0.68 and 0.66 with CH3OH as eluant and iodine vapour as developer. 

The various eluant and adsorbent systems used for thin layer chromatography of meprobamate are given in Table V. Table VI gives spray reagents used for the detection of meprobamate on thin layer chromatographs. 

Some polychlorinated gem-dichlorocyclohexadienones were separated by P. SVEC (6) using thin-layer chromatography on a silica plate with eluants of hexane, cyclohexane, and benzene type. Using hexane as an eluant it was possible to transpose this separation of elements to HPLC with a silica column (Fig. 3). 

These limitations have led to the development of forced flow development systems and to the technique of overpressured thin layer chromatography. The special feature of this method is that the adsorbent layer is in a completely sealed unit and the solvent is delivered under pressure at a controlled oniform flow-rate by a pump module as in HPLC. Thus, overpressured TLC (OPTLC) takes place in the absence of a vapour pressure and the migration of the solvent front is free from both evaporation and adsorption effects. As the eluant is delivered under controlled conditions it is possible to optimise the separation conditions by adjusting the flow-rate of the eluant and also to undertake continuous development proeedures. 

To undertake the separation of a mixture of analgesics by flash column chromatography (FCC) and to examine the eluant fractions by thin layer chromatography. 

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