cyclopentolate hydrochloride

[Robert Brightman]

I have a colleague who is trying to develop an HPLC method for cyclopentolate hydrochloride with possibility to detect 0.1% degradation products. Does anyone have any suggestions for obtaining correct peak shape and sensitivity? He has been trying with octane sulfonate + triethylamine pH 3/ acetonitrile on a Uptispher column.
A second question concerning sensitivity; we are now systematically asked to detect 0.1% degradation products and this often means injecting very concentrated solutions giving rise to overloading, peak deformation and other chromatographic phenomena. Does anyone have any suggestions for increasing sensitivity without overloading?

[Uwe Neue]

Some overloading phenomena are related to the injection solvent and can be solved by changing this. Some peak distortion phenomena can be solved by using modern tailing-free columns. Some peak distortion phenomena can be reduced at least 10 fold by changing the pH, i.e changing your analyte to a non-ionic form.

Beyond this, only better detectors can help.