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Cell Size on UV

Posted: Mon Aug 18, 2014 11:55 am
by jayroseville58
What if, there is no available 0.5cm cell size for UV analysis. Can we just adjust the standard and sample concentration indicated on the USP monograph so that we can use the available 1cm cell? If we can, then are we still going to conduct linearity or perform validation instead of verification base from the adjustment we made?

Re: Cell Size on UV

Posted: Mon Aug 18, 2014 12:47 pm
by bunnahabhain
Is this HPLC-UV or photometry using UV?
If photometry, I cannot imagine there are no 0.5 cm cells available (at least here in Germany we have http://www.hellma-analytics.com/startse ... /home.html they can provide every imagineable format).
And HPLC-UV: I don't even know the lightpath of my UV cells, do I have to worry about that?
Jörg

Re: Cell Size on UV

Posted: Mon Aug 18, 2014 12:54 pm
by kubowicz.tomasz
Hello

Is it UV detector cell or UV spectrophotometer cuvette?

Regards

Tomasz Kubowicz

Re: Cell Size on UV

Posted: Mon Aug 18, 2014 1:13 pm
by jayroseville58
Hello

Is it UV detector cell or UV spectrophotometer cuvette?

Regards

Tomasz Kubowicz
UV Spectrophotometer Cuvette

Re: Cell Size on UV

Posted: Mon Aug 18, 2014 6:32 pm
by DR
You would want to dilute everything by an extra factor of 2 so that you should be in the linear range of the method you are using, then calculate normally and report the deviation from the method in the assay documentation. In some labs, you need permission to do this sort of thing in advance.

PS - make sure your 1CM cuvettes are made of the same thing your missing, method specified, 5mm cuvettes are made of...

Re: Cell Size on UV

Posted: Tue Aug 19, 2014 5:03 pm
by Consumer Products Guy
I think it would be simpler to just buy 0.5 cm cuvette; if not: do what DR posted.