Fractionation by chromatography

The evaluation of petroleum must of necessity involve a study of composition because of the interrelationship of the physical properties and composition as part of the overall evaluation of different feedstocks. There are several ASTM procedures for feedstock/product evaluation  

Determination of aromatic content of olefin-free gasoline by silica gel adsorption (ASTM D936) 

Separation of aromatic and nonaromatic fractions from high-boiling oils (ASTM D2549) 

Determination of hydrocarbon groups in rubber extender oils by clay-gel adsorption (ASTM D2007) 

Determination of hydrocarbon types in liquid penoleum products by a fluorescent indicator adsorption test (ASTM D1319) 

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Nuclear extracts can be fractionated by chromatography on DEAE-cellulose to give three peaks of RNA polymerase activity (the use of column chromatography is explained in chapter 6). These three peaks correspond to three different RNA polymerases (I, II, and III), which differ in relative amount, cellular location, type of RNA synthesized, subunit structure, response to salt and divalent cation concentrations, and sensitivity to the mushroom-derived toxin a-amanitin. The three polymerases and some of their properties are summarized in table 28.4. 

Boduszynski et al. (1980) described an elaborate new separation procedure for isolating and concentrating chemically defined compound types rather than solubility types. A residuum (675°C+) is first fractionated by chromatography with an ion and cation resin to isolate acids and bases, followed by coordination chromatography on ferric chloride Attapulgas clay to separate the remaining neutral Lewis base and hydrocarbon fraction. This latter component is further separated into saturate and aromatic hydrocarbons over silica gel. 

If a reaction mixture obtained after 4 hours acidolysis of Bjorkman lignin (spruce), after neutralization and removal of the polymeric material, were filtered through a Sephadex G 25 column, the elution curve (Figure 5) exhibited three peaks (26). The effluent fractions corresponding to peaks A and B were subjected to further fractionation by chromatography on silica gel columns. We found that fraction A contained only monomeric products while fraction B was a mixture of dimeric products (Figures 6 and 7). 

To a solution of 56.6 g (0.25 mol) of anthralin in 1750 ml of absolute toluene and 27.3 ml of pyridine, 31.5 ml (0.3 mol) of butyryl chloride was added with stirring over 30 min at room temperature. The reaction mixture was then heated to 85°C for 1 hour. After this mixture had recooled to room temperature, 27.3 ml of pyridine and 31.5 ml of butyryl chloride were again added. The suspension obtained was then heated to 85-90°C for 1 hour. The precipitated pyridinium hydrochloride was eliminated by filtration then washed with toluene. The toluene filtrates were concentrated to around 500 ml under reduced pressure, washed several times with water then dried over magnesium sulfate. The product was then fractionated by chromatography on... 

Proton and Carbon NMR Spectra. The alkylated coal products were separated from the reductive alkylation products of naphthalene. The coal products then were separated into several fractions by chromatography on Styragel. The proton and carbon NMR spectra of the individual fractions were recorded. 

PVP separation. The remaining pigment was removed from the polyamide water fractions by chromatography on a 2.4 cm x 15 cm column containing 50 g polyvinyl pyrollidone (Polyclar AT, GAF Corp., Wayne, N. J.) as shown in Figure 4. The PVP was rinsed first with 1 column volume of water followed by 1 column volume methanol. The p-damascenone charm of each fraction was then determined. The water rinses were concentrated on a 1 cm x 20 cm column containing 40 g of 40 mm C18 reversed phase adsorbant and eluted with 2 volumes of 50% methanol/water. The p-damascenone charm of the eluate was determined. 

Bermejo J, Fernandez AL, Prada V, et al. 1999. Monitoring the synthesis of new pitches from coal tar and its fractions by chromatography and related techniques. J Chromatogr 849 507-519. 

Yoshikawa et al. isolated the crude saponin from G. syLvestrs=as follows The dried leaves were extracted with 60% EtOH at 60°C for two weeks. The EtOH extract obtained after evaporation of the solvent in vacuo was passed through an Amberlite XAD-2 column and eluted with MeOH. The MeOH eluate was psssed through Toyopearl HW-40 column (MeOH) to give the crude saponin. The crude saponin was further fractionated by chromatography on Servachrome XAD-2 (elution with 40-70% MeOH). 

Barbezat-Debreuil, S. Emde, aux rayons X, des paraffines du tabac fractionee par chromatographie [A smdy with x-rays of tobacco paraffins fractionated by chromatography] 1. Recherche Centre Natl. Sci. Lab. Bellevue (Paris) 45 (1958) 273-277 Compt. Rend. 246 (1958) 2907. 

Figure 9.15 Typical mass spectrometry based experiment for protein identification/characterization. (1) Proteins are fractionated by chromatography, separated by sodium dodeyl sulphate (SDS) polyacrylamide gel electrophoresis (PAGE), then excised from gel (2) the protein of interest is digested into peptide fragments, that are then (3) identified by ESI MS/MS (4) the first dimension involves molecularion analysis for peptide mass finger-printing (ql, MS only). (5) Tandem MS/MS is used when protein identification is not unambiguous, in which case parent molecular ions are activated by CID (q2) and daughter (product) ions are characterized (ToF) according to the technique of product ion scanning (illustration from Aebersold and Mann, 2003, Fig. 1).

A cell-free extract of Mycobacterium smegmatis was separated into the two fractions by chromatography on 0-(2-diethylaminoethyl)-cellulose. Fraction A catalyzed synthesis of Q ,a-trehalose from GDP-D-glucose, but was relatively inactive with UDP-D-glucose. However, when Fraction B was added to Fraction A, UDP-D-glucose was able to serve as an effective D-glucopyranosyl donor for synthesis of a,a-trehalose. Under these conditions, GDP-D-glucose was still... 

Nasuno and Starr reported the enzymic, j8-eliminative degradation of D-galacturonan by means of an enzyme, from the culture fluid of Xanthomonas campestris, that had been purified by precipitation with acetone and fractionation by chromatography. The activity of the enzyme was further tested on oligosaccharide fragments, such as 59, having a terminally linked, unsaturated deoxyhexopyranuronate unit. It was demonstrated that the enzyme acts in a random manner it does not act... 

The mother liquors from the purification of the product were combined and evaporated to dryness. The residue was fractionated by chromatography over silica gel (Kieselgel) and elution with a 7 3 mixture of benzene-ethyl acetate. The first fractions were discarded and the ensuing fraction was evaporated to obtain colorless crystals. The product was purified by mixing with five volumes of boiling isopropyl ether and the crystals formed after cooling were recovered by vacuum filtration, were washed twice with two volumes of isopropyl ether and dried in a ventilated atmosphere to obtain 1701,21-dimethyl-19-nor- A4-9... 

C39H64O2S2, Mr 631.07, orange-red oil, [alu -5° (CHCls), component of the extremely thermophilic and acidophilic archaebacterium Caldariella acidophila. C. is obtained from the lipid fraction by chromatography on silica gel. 

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