I'm involved in a method transfer for a HPLC method using UV detection. What is the maximum allowable absorbance for a peak? I have heard some say 1.0 AU, and others say 1.5 AU. Can anyone lead me to any articles on this? Thanks.

This question is not as simple as saying 1 or 1.5 or 2 AU. The answer depends on a number of factors including, brand of detector, flow cell path length, mobil phase composition, flow rate, sample UV maximum and probably several other factors that I can not think of right now. So what do you do? Run a standard curve and find out at which concentration your sample liniarity begins to degrade. At this point you have reached the maximum absorbance for your situation.

Noname,
Anonymous #2 answers is the best bet. Don't take anyone's word for a specification when you can easily test it.

The literature is full of bad advice. The worst for your UV detector is the 37% (about .3 absorbance) which was good advice for the bolometer but not the photodiode or photomultipler in the instrument you will buy. The diode probable functions optimally about 1 but stray light probably limits the detector more than detector response. To go more than absorbance of ~2 usually requires a dual monochrometer design, not too likely for a HPLC detector because of cost. For most detectors get wary if the absorbance goes above 1.8.
Jim