The Impurity from Hell revisited: The Impurity from Hell for Pregabalin

kilomentor | 13 October, 2010 18:33

The Kilomentor Blog is now being continued and updated at This particular article appears at



Pregabalin unknown impurity

anupriya | 05/05/2011, 09:51

Can u help me in identification of a unknown impurity of pregabalin having mass value 157 in LCMS.The impurity is early eluted in HPLC column i.e. comes before the peak of Pregabalin.

pregabalin Impurity

kilomentor | 09/05/2011, 12:01

Kilomentor does problem solving consulting as a business. Good hypotheses about the possible identity of unknown impurities can be often be made quickly but much more data is required. The work is done after a confidentiality agreement is signed to protect you and a prepayment has been made to protect me. If this is of interest send an e-mail to
Initial pertinent questions that you can ask yourself are:
What was the route of synthesis of this sample?
What is the exact mass for the impurity? (this will limit the possible molecular formulae)
Does the impurity have any enhanced UV absorption bands compared to the pregabalin main peak? (This can be obtained from the output of a variable wave HPLC detector).

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