A product with 2% Hydroquinone keeps getting a high HQ reading using the HPLC method.

Hello,  I’m new to this so please excuse me if I do something incorrectly.
Anyway, I am having a lot of difficulty with a product that is an OTC with 2% Hydroquinone in it.
Every batch is tested for HQ levels and the results consistently come back with a high recording.
Is there something that could be in the formula that is having a negative impact on the HQ?
Is there a class of chemicals that would cause an HQ level to spike?

Thank you and much appreciated for ny insight you might be able to give me.


  • DuncanDuncan Member, Professional Chemist
    The question is is there anything in the base that is either coming through at the same time as the HQ, or something in the background that is giving a high absorbance on the UV detector.
    Obvious question have you tried HPLC of base with no HQ in there to see what you get? If that's giving a peak where you'd expect HQ to be that may be the answer, and you'll need to revalidate the method to get around that
    UK based, Over 20 years in Toiletries, After a 5 year sabbatical doing cleaning products, back in the land of Personal Care
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