Chromatography developing solvents

Table 4 Thin-layer chromatography developing solvents for dye analysis...

Purified by chromatography on partially deactivated alumina or magnesia, or by using a thin layer of silica gel G with 4 1 cyclohexane/diethyl ether as the developing solvent. Stored in the dark at -20°. 

Infrared spectra were obtained with a Perkin-Elmer 1800 and a Nicolet Magna-IR 750 FTIR spectrophotometer, and the absorption frequencies are reported in wave numbers (cm4). NMR spectra were obtained with BZH-300 and CA-F-300 Bruker FTNMR 300 MHz spectrometers. Chloroform-d was used as solvent, and all chemical shifts are reported in parts per million downfield (positive) of the standard. H-NMR and 13C-NMR chemical shifts are reported relative to internal tetramethylsilane, while 19F-NMR chemical shifts are reported relative to internal fluorotrichloromethane, Rf values were obtained from silica gel thin-layer chromatography developed with a mixture of 1.5 mL methylene chloride and three drops of acetone. The number of hydrate water molecules was calculated from the integration of H-NMR spectra. 

Place the development solvent (l-propanol ethyl acetatexoncentrated NH4OH, 1 1 1) in the developing tank, and develop the chromatography plate so that the solvent migrates for 12 cm. 

Liquid chromatography was carried out utilizing a Hitachi model 63M adsorbent Hitachi gel 3010, developing solvent methanol, detecting wavelength 280nm). 

Baker Chemical Co. Molinate sulfoxide was prepared by reacting [ring- Cjmolinate with equimolar m-chloroperbenzoic acid in chloroform (10). The product was puriTied by preparative thin-layer chromatography (TLC) using acetone hexane (1 1) as the developing solvent. The final radiopurity was 98%,... 

Because of the similarities in the theory and practice of these two procedures, they will be considered together. Both are examples of partition chromatography. In paper chromatography, the cellulose support is extensively hydrated, so distribution of the solutes occurs between the immobilized water (stationary phase) and the mobile developing solvent. The initial stationary liquid phase in thin-layer chromatography (TLC) is the solvent used to prepare the thin layer of adsorbent. However, as developing solvent molecules move through the stationary phase, polar solvent molecules may bind to the immobilized support and become the stationary phase. 

El 2. Predict the relative order of paper chromatography Rf values for the amino acids in the following mixture Ser, Lys, Leu, Val, and Ala. Assume that the developing solvent is iz-butanol, water, and acetic acid. 

Lipids that have both polar and nonpolar portions (fatty acids, etc.) tend to streak or tail during thin-layer chromatography development. This leads to long, narrow spots after iodine treatment. Addition of a small amount of a very polar solvent (acetic acid) greatly reduces this tailing and results in a more circular, better resolved spot. 

Thin layer chromatography is yet another means for determining identity of moxalactam materials. The mobility of the moxalactam sample must be identical to the mobility of the moxalactam reference standard which is run on the same TLC plate. The developing solvent for TLC consists of 42 parts ethyl acetate 14 parts glacial acetic acid 14 parts acetonitrile and 18 parts water. A silica gel type F plate is used and is viewed under short wavelength UV light to detect the position of the components on the developed plate. 

Hexosamines. Hexosamines, in paper chromatography, are, like the sugar acids, sensitive to the pH of the developing solvent. Partridge... 

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