PAPER CHROMATOGRAPHY 37 



O 



to be used; then 5 to 10 ^1 of sample was applied in a spot at a marked 

 position on the strip. A potential of 5 vohs/cm was employed. jVIost 

 workers have used barbiturate (veronal) buffer of pH about 8.5 for the 

 separation of plasma proteins. However, Zilversmit and Hood (34) have 

 pointed out that such buffers may cause artifacts and should be employed 

 with caution. It was shown that blood plasma itself may be used as a 

 buffer to avoid these possible alterations. 



Paper electrophoresis has been utilized for studies of sugars (35), serum 

 and body fluids (36 to 38), and lipids (39). 



ORGANIC SEPARATIONS 



Table 8-2 presents a summary of paper-chromatographic procedures 

 that have been used for various groups of organic substances. This table 

 has been compiled primarily from general references (8, 10a), which 

 should be consulted for additional details. A similar compilation has 

 been presented by Williams (9). The listing is primarily by major 

 groups of compounds and is presented to indicate the scope of the method. 



INORGANIC SEPARATIONS 



Tables 8-3 and 8-4 present a summary of paper-chromatographic pro- 

 cedures that have been used for various inorganic ions, as compiled by 

 Block (8). The text of Smith (6) should be consulted for details of inor- 

 ganic separations. Frierson and Jones (13) hav^ demonstrated the use 

 of radioisotopes in partition-chromatographic separation of various inor- 

 ganic ions. Separations were made of the following mixtures of radio- 

 isotopes: (a) iron-cobalt, (b) iron-cobalt-nickel-manganese-zinc, (c) lead- 

 bismuth, (d) lead-bismuth-polonium, (e) sodium-potassium, and (/) 

 titanium-scandium. Location of the elements on the paper strip was 

 determined by visual appearance, autoradiograms, or automatic scanning 

 with a Geiger tube. In general, the definition of spots by scanning was 

 not so precise as by autoradiography. However, the scanning method 

 was faster. It was possible to differentiate the resolved mixtures by 

 differences in radiation energies (Ni^^-Co^^, Na-^-K^^), by growth of 

 daughter activities (Pb'^" in Ra DEF), and by differences in decay (Xi^^- 

 Zn^^-Fe*^). Of practical import is the use of such procedures to check 

 the purity of radioisotope preparations before their use in experimental 

 work. 



APPLICATIONS 



The widespread application of paper chromatography has been indi- 

 cated bv the summaries in Tables 8-2 to 8-4, and the current literature 



