Starch Chromatography

Drs. Moore and Stein of the Rockefeller Institute have studied the quantitative amino acid content of gramicidins A and B by starch chromatography. Figure 4 is an elution curve of gramicidin A. Here the concentration is estimated by the sensitive ninhydrm color test. 93% recovery of the nitrogen is accounted for. It has not proven possible... 

Al. Alexeenko, L. P., and Orekhovich, V. N., A method for proline and hydroxyproline determination by means of ninhydrin reaction in acid medium after starch chromatography. Dokl. Akad. Nauk SSSR 133, 690-693 (1960). 

Fig. 6.2 Starch chromatography—A.J.P. Martin and R.L.M. Synge— Nobel Prize 1952. Royal Institute of Chemistry 1877-1977. Stamp issued by Great Britain in 1977...

Size exclusion was first noted in the late fifties when separations of proteins on columns packed with swollen maize starch were observed (Lindqvist and Storgards, 1955 Lathe and Ruthven, 1956). The run time was typically 48 hr. With the advent of a commercial material for size separation of molecules, a gel of cross-linked dextran, researchers were given a purposely made material for size exclusion, or gel filtration, of solutes as described in the classical work by Porath and Flodin (1959). The material, named Sephadex, was made available commercially by Pharmacia in 1959. This promoted a rapid development of the technique and it was soon applied to the separation of proteins and aqueous polymers. The work by Porath and Flodin promoted Moore (1964) to apply the technique to size separation, gel permeation chromatography of organic molecules on gels of lightly cross-linked polystyrene (i.e., Styragel). 

Staggered conformation, 94 molecular model of, 94 Stannous chloride, reaction with nitroarenes, 928 Starch, 1—>4- -links in, 1000 structure of, 1000 Stationary phase, chromatography and, 432... 

PCS. Partition chromatography on starch column 196, 261). MBA. Microbiological assay. 

A three-step nitration process of toluene is described. The advantages of the modified process are reduced waste, less hazardous operation, reduced oleum requirement, partial replacement of coned HN03 with dil HN03, and higher rate of toluene flow into the reactor (Ref 86) The continuous process of H.C. Prime (Ref 73) for preparing TNT was studied by thin-layer chromatography on silica gel with a starch binder and a fluorescent indicator. The nitration... 

Att eZcven y-cJuiin voA nts, discovered thus far, exhibit a change In electrophoretic mobility, and starch gel electrophoresis Is the recommended method for their detection. Quantitation of the variant can best be done by chromatography on columns of either DEAE-Sephadex or CM-Cellulose. The quantities of some variants In heterozygotes differ greatly. For Instance, the relative amount (expressed In %F /Fxotal) varies from 20-25% (F-Malta-I) to 10-15% (most Y C >aln variants) to 5-6%... 

The, chain voAiantS are characterized by the presence of two abnormal components, an abnormal Hb-F (02 /2) and an abnormal Hb-A (tt2 32) Of these two, the 02 2 component dominates and the 02 32 component Is often difficult to detect. The methods of choice are starch gel electrophoresis and anion-exchange chromatography using DEAE-Sephadex or DE-52 Cellulose. Chain analyses of these Isolated hemoglobin components will lead to a definitive Identification. 

Hb-B0Jut 6 OK yif can best be demonstrated by either cellulose acetate or starch gel electrophoresis. The amount of Hb-Bart s can differ from 1% to over 80% dependent on the abnormality Involved. Quantitative determination Is most accurately made by CM-Cellulose or CM-Sephadex chromatography. 

The only pectic enzyme thus far obtained in crystalline form is the endo-D-galacturonanase from Acrocylindrium.209 Crystallization of the enzyme from a solution of ammonium sulfate was preceded by chromatography on calcium phosphate, Duolite CS 101, and DEAE-cellulose, and by starch-gel electrophoresis. 

The first thing you need is an adsorbant, a porous material that can suck up liquids and solutions. Paper, silica gel, alumina (ultrafine aluminum oxide), corn starch and kitty litter (unused) are all fine adsorbants. Only the first three are used for chromatography. You may or may not need a solid support with these. Paper hangs together, is fairly stiff, and can stand up by itself. Silica gel, alumina, corn starch, and kitty litter are more or less powders and will need a solid support to hold them. 

This chromalographic method is convenient and useful in a number of cases. Crystals of quartz which are chiral exhibit different adbsoptive power for several antipodes and so also starch has been employed. Gas-liquid chromatography (GIC) is also employed to resolve racemates. For example to separate racemic a amino acids they are converted into esters with optically active alcohols like (-)2 butanol or trifluroracetyl devivatives, which are then separated by GLC. 

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