Column inorganic

In the case of di- and oligo-saccharides, a simpler method may be employed. The aqueous extract of the pherogram is added to a short carbon-Celite column, inorganic material is eluted with water, and the carbohydrate is subsequently eluted with aqueous ethanol. This method may be used for any substance which is not readily eluted from a carbon-Celite column by water but which can be eluted with aqueous ethanol. Alternatively, the saccharide extracted from the pherogram may be acetylated. ... 

In most inorganic chromatography, resins of 100 to 200 mesh size are suitable difficult separations may require 200 to 400 mesh resins. A flow rate of 1 mL cm min is often satisfactory. With HPEC columns, the flow rate in long columns of fine adsorbent can be increased by applying pressure. 

Descriptive properties for a basic group of inorganic compounds are compiled in Section 3, which has undergone a small increase in the number of entries. Many entries under the column Solubility supply the reader with precise quantities dissolved in a stated solvent and at a given temperature. 

The gel-like, bead nature of wet Sephadex enables small molecules such as inorganic salts to diffuse freely into it while, at the same time, protein molecules are unable to do so. Hence, passage through a Sephadex column can be used for complete removal of salts from protein solutions. Polysaccharides can be freed from monosaccharides and other small molecules because of their differential retardation. Similarly, amino acids can be separated from proteins and large peptides. 

Inorganic packings (silica, alumina, etc.) are very stable (yet brittle) and show very high pore volumes (i.e, efficiency). However, their chemical stability is very limited and the surface is very active (this is also true for reversed-phase columns), allowing their use in special applications only. 

Reference has been made to the problems associated with the presence of highly involatile analytes. Many buffers used in HPLC are inorganic and thus involatile and these tend to compromise the use of the interface, in particular with respect to snagging of the belt in the tunnel seals. The problem of inorganic buffers is not one confined to the moving-belt interface and, unless post-column extraction is to be used, those developing HPLC methods for use with mass spectrometry are advised to utilize relatively volatile buffers, such as ammonium acetate, if at all possible. 

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