Condensed phosphates paper chromatography

Since the labeling technique was introduced, a large number of further publications on the paper chromatography of phosphates have appeared (159), but these papers will not be considered separately here. They serve to confirm what was already partly known, and they describe improvements in technique, thereby reducing the risk of hydrolysis of the condensed phosphates in the acid medium used in chromatography. They also show how the accuracy of quantitative analysis could be increased (226). 

Highly condensed polyphosphates, which cannot be separated by paper chromatography may be separated into groups by paper electrophoresis 255). Paper chromatography allows the complete separation and quantitative determination of all condensed phosphates with n up to 10, but its use is limited to 7-quantities. 

Aldolizations of trioses, with formation of hexoses, have been observed in several investigations. Meyerhof estimated that the triose-hexose equilibrium mixture from the condensation of OL-glycerose with 1,3-dihydroxy-2-propanone (in trisodium phosphate solution) contained 92% of hexose. Berl and Feazel, in their kinetic examination of this aldolization in sodium hydroxide solution, were unable to detect any triose by paper chromatography at the end of the reactions. Pyruvaldehyde formation complicates any glycerose or 1,3-dihydroxy-2-propanone reaction in alkaline medium, and this fact probably accounts for some of the disappearance of triose from these mixtures. Nevertheless, aldolizations of these short-chain sugars are side reactions to be reckoned with, whenever circumstances permit their occurrence. 

Even if the instrumental techniques gain ever more ground, some of them in automated form, evaluated and documented by computer, the simple, manual methods such as paper and thin-layer chromatography still have their role to play. One need only think of the separation of the various forms of phosphate such as orthophosphate, pyrophosphate, metaphosphate, polymeric phosphates and condensed phosphates, or the separation of polycyclic aromatic hydrocarbons (specifically with thin-layer chromatography) in water analysis. 

If not easily hydrolysed to soluble orthophosphates, condensed phosphates are usually best identified and estimated by the techniques of paper chromatography or x-ray diffraction (XRD) (see below). Several purely chemical methods are, however, known. 

H. Grunze and E. ThUo, The Paper Chromatography of Condensed Phosphates. 

The one-carbon unit from serine is transferred to the Jif of tetrahydrofolic acid. This reaction requires pyridoxal phosphate and Mn++. There is evidence that the first step in this reaction is a condensation of serine with tetrahydrofolic acid in a reaction that does not require additional cofactors. The condensation product was identified by paper chromatography as a colored compound with a characteristic fluorescence. In a second step pyridoxal phosphate and Mn++ are required, and glycine... 

---