Efficient Procedure for Solvent Deaeration in Column Chromatography.

Chromatography

“…Automatic stepwise elution requires special valving (911,924,1576). Some of the gradient elution devices in the recent literature (28,265,335,379,646,780,1688,1696) are especially designed to deliver concave (61,1126) or linear (280) gradients; others can be deaerated (808) or used anaerobically (1342). 686) a suspension of adsorbent on an ordinary glass plate, although the latter technique is not suitable for accurate work (1191).…”

“…used for C1'-labeled fatty acids(237).Except are converted to iron-cobalt rhodanates(474) or heavy metal soaps(22,808,682), which may be further transformed to the metal sulfides(22,308). Salts…”

The Chemistry of Peptides and Proteins

“…It i s therefore appropriate to mention a significant advance i n the chromatographic determination of these derivatives. Kesner and his colleagues (22) hwe described an automatic column method f o r both dinitmphenyl amino acids and peptides. The coluran i s prepared under i n an experiment i l l u s t r a t e d by these authors, the resolution was satisfactory f o r a l l the derivatives except the two ( leucine and isoleucine) that migrated most rapidly on the column.…”

Automatic Column Chromatography of Ether and Water-Soluble 2,4-Dinitrophenyl-Derivatives of Amino Acids, Peptides, and Amines.

“…Attempts to use hydrated silica variations in the properties of different silica gel preparations, frequent cracking of columns, the requirement of multiple short columns utilizing a variety of developing solvents, and the necessity of running, simultaneously, reference standards on equivalent columns for identification purposes. In attempting to apply hydrated silica gel columns for the fractionation of organic acids and DNP-derivatives, the present authors (8) noted that the cracking and channeling of the columns could be eliminated if the eluting solvent were properly deaerated. As a result it became possible to use hydrated silica gel columns of 100-cm.…”

“…Numerous techniques for identifying the 2,4dinitrophenyl (DNP)-derivatives have been reported (I), including paper chromatography, column chromatography, paper electrophoresis, and countercurrent distribution. Column chromatography of the DNP-derivatives employing a variety of supporting materials, such as silica gel (1, 11¡), Kieselguhr (10), Celite (9,11,12), silicic acid-Celite (8,16), ion exchange resin (18), and nylon powder (4,20) has met with variable success.…”