Peak Shape problem

[Santosh Gandhi]

Hello,
Iam developing a hplc method for monitoring reaction . The starting material (7-Phenyl acetamido-3-Hydroxy-3-Cephem-4-Carboxylic acid diphenylmethyl ester i was told that keto -enol tautomerism is possible) gives better peak shape only at pH below 7 ( at pH above 7 the peak tails badly [it drags] , but the intermediates formed degrades at pH below 7. how to go about.

Thank you
Santosh Gandhi

[JGK]

How exactly are you monitoring the reaction?

Are you trying to quantify all items Including the intermediates?

or

Just measuring decease in starting material/increase in product?

If it is the last option does the degradation of the intermediates affect chromatography?

Also how long does it take the Keto - Enol tautomerism to reach equilibrium?

(I am asking as I once had a an assay where the analyte took 2 hours to reach a tautomeric equilibrium. Attempting analysis before this point gave very poor calibrations and irregular peak responses).