Weird UV sprectra

[kate_m]

Hey everybody!

i have noticed sometimes my UV spectra are a little bit weird. i get negative absorbance and weird shapes.

does any one know what causes this?

Im using agilent DAD 1260 infinity series and Chromeleon software.

i attached 2 pics. They're two peaks far from another but with almost 'identical' spectra by the looks of this ( i know thats not true )





Is it interference or something? or dirty peaks i.e co-elution?

thanks in advance!

kate

[pwm]

Hi Kate,

I was not able to see your images posted. What do you mean by two peaks far from another? RT?

What are your detector settings, scan range, mobile phase?

If you have an agilent controller or Lab advisor you could run a few diagnostics tests, lamp intensity and cell test might be most relevant. How many hours on the lamps? May be worth checking with a new lamp?