Chromatography Forum

Hi,
I am analyzing by RP-HPLC a complex extract from plants. This extract contains a wide range of compounds, with huge variations in concentration and UV response and I need to quantify them. I have found out that, to achieve good peaks also for the minor components, I have to use a concentration of the extract which causes the major peaks reaching an absorbance of 2500 mAu…
I have read on the specification of the UV-detector (Agilent MWD 1100 series) that the linearity range is > 2 Au.
Can I trust it? Will my quantitative analysis be correct?

thanks

Even if it´s linear for your substances at such high absorption, you may have a strongly absorbing baseline such that you detector "sees black" at a highly absorbing sample. I don´t see how you can get around checking the linearity by dilution series.