Glucose and phosphate identification HPLC

Question

Hi, 
 I need to analyse phosphate and glucose in the same analysis on HPLC I have tried using different columns such as Aminex HPX-87H Column 300 x7.8 mm, Agilent Hi-PLex H, 7.7 x 300 mm, NUCLEOGEL SUGAR 810 H, 300x 7.8 mm... but none of these manage to separate the two peaks which remain superimposed... does anyone perhaps know of a different column to use or suggestions for parameters considering the analytes? Or any suggestions considering the properties of the compounds ? 
 Best, 
 Chiara

Dr. Know · Accepted Answer

For glucose a 87H type is ok as it uses Ion Exclusion Chromatography for the separation, the phases contain benzenesulfonic acid group (and will interact with anions in ion exchange mode). Phosphoric acid does not interact with sulfonic acid groups as it is a cation needing something like quaternary amines to interact with. 
 You could do a solid phase extraction first either remove the glucse by Bond Elut PBA or the phorphate with Bond Elut SAX, otherwise I see little chance with LC alone unless you use a strong ion exchange column to retain the phosphate very long and have glucose elute early.

Glucose and phosphate identification HPLC

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