[coquim]

Hi people!!

i´d like to know what is the correct baseline stability criteria before to start running...i mean, detail level of mv must i see and slope and drift acceptable before to begin...
thank for your advices!...

[Arkcon]

That's pretty hard to give a straight number on, for one thing, you'd only know after the run, if your baseline was good enough, and it really does depend on your application.  FWIW, in some applications I've worked with, an impurity peak can be ignored if it's less than 5 times the noise, for other applications, in the same group, all peaks were significant, provided they are greater than the noise over a respectable interval.  But that only helps you in a roundabout way -- noise and drift must be significantly less than what you expect to be analyzing, but you don't know what that is, until you try. 

[coquim]

noise and drift must be significantly less than what you expect to be analyzing

Thanks "A"!, you´re right of course...but, do you know how much do i must expect?

[JGK]

I suggest you refer to http://www.ich.org/cache/compo/276-254-1.html

and download the document "Q2(R1): Validation of Analytical Procedures: Text and Methodology"

This is pretty much the "industry" Standard

[Arkcon]

I suggest you refer to http://www.ich.org/cache/compo/276-254-1.html

and download the document "Q2(R1): Validation of Analytical Procedures: Text and Methodology"

This is pretty much the "industry" Standard

Now that is an excellent link.  Not only apropos, but I wasn't aware of an international body attempting a reconciliation of US/EU/B/J Pharma.  Top marks.

*[EDIT]* Didn't mean to forget one there.

[coquim]

thanks!, i´m reading it, and i could see the doc. is very very similar to those i´ve found in pharmacopoeia´s...

[JGK]

It's pretty much the definitive document for those of us working in GLP environments on Non-bioalalytical assays  Most of the GLP guidance documents referto it or use it in their guidelines.

[Arkcon]

It's pretty much the definitive document for those of us working in GLP environments on Non-bioalalytical assays  Most of the GLP guidance documents referto it or use it in their guidelines.

Har-upmph.  And all the cGMP documents I've read leave us hanging on these issues.  Governments not playing fair doesn't stop at bombs and armies, apparently.  But I shoulda known that.