Impurity peak in WORKING STANDARD

[syedzahidhussain]

I see an impurity peak in the working standard. System suit and all other criteria pass. What is the limit of imurities that I can ignore or what is the maximum area of the impurity that can be disregarded according to USP?

Thanks in advance

[HPLCaddict]

What does your SOP say?

Ph. Eur. suggests a general disregard limit of 0.05% (chapter 2.2.46) if I recall correctly.

[syedzahidhussain]

Thanks for the reply. SOP does not comment anything on impurity in WOrking standard. However it does limit amount of impurity in the sample.