If my inferences are right then I suspect that the solution to your problem lies with somebody with very specific expertise in the method and chemistry that you are using... Probably not this forum.
Judging by the image you provided, your HPLC has a quaternary pump and I don't recognise the interface, so it's probably a Waters system? A very nice and rather capable one by the looks of the parameters!
I wondered why you didn't specify the column or specific mobile phases, so I assume that either you don't want us to know (which I thought was unlikely as it's hardy likely to be part of an NDA) or perhaps you don't know. If the latter then you're probably using a proprietary kit like AccQ-Tag which includes 2 eluents which contain who knows what, although the MSDS might give you some idea.
If this is right, then to be quite honest, your best option would be to talk to Waters who should be able to provide some advice. You might also like to look up a publication by somebody called Fosia Dahir Jada from the University of Uppsala if you haven't already.