Paper chromatography Subject

This recrystallised acid is pure in the norm y accepted sense of the word, namely it has a sharp m.p. and gives on analysis excellent values for carbon, hydrogen and nitrogen. If however it is subjected to one-dimensional paper chromatography (p. 53), the presence of traces of unchanged anthranilic acid can be detected, and repeated recrystallisation is necessary to remove these traces. 

C. Isolation and purification of XK-62-2 100 g of the white powder obtained in the above step B are placed to form a thin, uniform layer on the upper part of a 5 cm0X 150 cm column packed with about 3 kg of silica gel advancely suspended in a solvent of chloroform, isopropanol and 17% aqueous ammonia (2 1 1 by volume). Thereafter, elution is carried out with the same solvent at a flow rate of about 250 ml/hour. The eluate is separated in 100 ml portions. The active fraction is subjected to paper chromatography to examine the components eluted. XK-62-2 is eluted in fraction Nos. 53-75 and gentamicin Cja is eluted in fraction Nos. 85-120. The fraction Nos. 53-75 are combined and concentrated under reduced pressure to sufficiently remove the solvent. The concentrate Is then dissolved in a small amount of water. After freeze-drying the solution, about 38 g of a purified preparate of XK-62-2 (free base) is obtained. The preparate has an activity of 950 units/mg. Likewise, fraction Nos. 85-120 are combined and concentrated under reduced pressure to sufficiently remove the solvent. The concentrate is then dissolved in a small amount of water. After freeze-drying the solution, about 50 g of a purified preparate of gentamicin Cja (free base) is obtained. 

From 9 liters of urine from a subject with chronic myeloid leukemia 16.4 mg 3-hydroxykynurenine and 40 mg kynurenine, as the sulfate, were isolated through the mercuric salts, resolution with hydrogen sulfide, preparative paper chromatography of the concentrate, elution of the fluorescent bands, and repeated concentrations and crystallizations. From 5.5 liters of urine from a patient with Hodgkin s disease 34 mg kynurenine and 21.1 mg 3-hydroxykynurenine were obtained. A third patient also with Hodgkin s disease gave 23.8 mg kynurenine and 9 mg 3-hydroxykynurenine... 

In the following Sections, the various types of carbohydrate which have been subjected to zone electrophoresis have been classified arbitrarily. In view of the fact that zone electrophoresis is, as yet, relatively little used in carbohydrate chemistry, an attempt has been made to emphasize and illustrate the applicabihty of the technique and to compare it, at the appropriate point, with paper chromatography, rather than to compile a catalog of applications. 

This chapter treats several separation methods that are not readily classified, including supercritical fluid chromatography, paper chromatography, capillary electrophoresis, capillary electrochromatography, and field-flow fractionation. The use of CE for DNA sequencing is the subject of a feature in the electrophoresis section of this chapter. 

A procedure involving GLC for the quantitative estimation of aldosterone in urine has been described by Bravo and Travis (B19). After preliminary purification and paper chromatography, the aldosterone is oxidized with periodic acid to aldosterone y-lactone which is extracted and subjected to GLC, using aldadiene as an internal standard. Figure 6 shows the GLC peak characteristics obtained for aldosterone y-lactone and aldadiene. The results obtained by this procedure are compared (B19) in Table 5 with those obtained by a double isotope derivative assay (K9). 

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