Ion exchange interactions on silica gel layers. III. Salts of organic bases with organic acids. Organic acids and sodium salts
Vámos, J.; Brantner, A.; Gracza, I.; Lásztity, A.; Józan, M.
Acta Pharmaceutica Hungarica 59(2): 69-86
1989
ISSN/ISBN: 0001-6659 PMID: 2544076 Document Number: 327144
By thin-layer chromatographic and spectroscopic (UV, IR) methods it has been proved that bass and acid are formed from salts of organic bases with organic acids during primary interaction because of the ion exchange behaviour of the silica gel layer. The organic acids formed have interacted with metals on the layer during secondary ion exchange and they migrate further as salts again. It has also been established that the extent of secondary ion exchange between metal silanate groups and acids depends on pKS values of acids. On the basis of investigations it can be ascertained with great probability that organic acids of pKS greater than 7 do not interact with metal silanate groups of silica gel layer. Sodium salts of organic acids of pKS less than 3 values similarly do not interact on the other hand sodium salts of organic acids of pKS greater than 3 values are able to interact with silanol groups. It has been established by flame atomic emission method that salicylic acid interacts with sodium ion and 86% of it migrates further as sodium salicylate.