220 



Discussion 



DISCUSSION 



Zweymiiller: The identification of organic acids in urine by paper 

 chromatography is elegant and of general application. The Rp values 

 of the different organic acids are distinctly different and therefore a clear 

 separation on the paper is possible. We used the technique developed by 

 Nordmann and co-workers (1954. C.R. Acad. Sci., Paris, 238, 2459), 

 and Fig. 1 demonstrates the position on a two-dimensional descending 

 chromatogram of some non- volatile, water-soluble organic acids which 



05 

 Et OH-NH3-H2O 



Fig. 1 (Zweymiiller). The position of some organic 

 acids in the urine of a normal adult on a two-dimen- 

 sional descending chromatogram. 



Ci = Citric acid, Ta = Tartaric, Ma = Malic, 



Gly = Glycolic, a-ce = a-ketoglutaric, Su = Succinic, 



Ac ^Aconitic, Glu = Glutaric, p-hy = [B-hydroxy- 



butyric, La = Lactic, Hi = Hippuric. 



Nordmann has found in the urine of normal adults. There is clear separa- 

 tion of citric acid, tartaric, malic, a-ketoglutaric, succinic, aconitic, lactic, 

 glycolic, hippuric, glutaric and p-hydroxybutyric acids. One spot applies 

 to both sulphate and phosphate, if there is any phosphate in the urine. 

 Using this method the organic acids give yellow spots on a blue-greenish 

 background. These spots have the advantage that they do not fade but 

 get more intense with time. We have so far examined urines passed by 

 newborn babies on the first, second and seventh days of life, but we have 

 not done enough to give a complete answer yet. Citric acid appears to be 



