Chromatography Forum

I am running an analysis for a sample DCVC Anhydride and all I need is a consistent set of injections with regard to peak area for it to pass. In my run there is one impurity. This wouldn't be a problem except that the peak area keeps fluctuating between it and the DCVC Anhydride area.

It went from 68:32, 70:30, 72:28. The injections should be within 1% for a pass result. The diluent is ethyl acetate. Injection volume is 1.5ul in a 5ul syringe.
There were other Standards that I ran with the same method and column that passed easily.
Why is it failing only for this one? I'm thinking injection volume is too high.

What type of injection are you doing, split or splitless?

What size liner do you use?

What is the stationary phase of the column?

Other inlet parameters will help to determine if the injection is too large or not, like column flow, initial temperature, split flow, inlet pressure, ect.