BLANK INJECTIONS

[achu729]

Does anyone know if it is required by FDA that we identify all peaks present in the blanks? What if these blank peaks are sporatic? I noticed some blank peaks in my blank and they may interfere with my peak of interest. Will it still be okay to proceed with a validation if this occurs? In order words, can we "ignore" blank peaks if they only occur sporatically due to "possible contamination"?

[HW Mueller]

How can you ignore that your analysis might be totally wrong?

[DR]

The root cause of "occasional" interfering system peaks needs to be found and eliminated. Start screening your mobile phase components for contaminants. If they're all good, passivate your HPLC and try again...

[Consumer Products Guy]

Agree with previous posters. We do not identify peaks not in the retention area of interest. If resolution of said peak is just over 2.0, then we try to identify it so we know what the critical pair is for the separation; and remember, our type of products contain fragrances, some components of which have UV absorption.

[achu729]

Thanks. So far, I have tried 2 different HPLC systems, 3 different batches, using the same column. I then tried pumping my gradient without the column, and the "blank peak" was not present anymore. A manager recommend I try to inject with just the guard, then the column, the the combo itself.