[Harrij]

I need to find a good analytical way to determine the acid value in DADPM (4,4'-Diamino diphenyl methane).
I use 1-propanol which is injected with a little HNO3. This is reacting with DADPM .
IF the DADPM is contaminated with HCL a acid result needs to be the result.
My PROBLEM in this:  WHY, do I get two curves ( endpoints ) when both acids involved are the value1 ( I guess you understand what I mean )

MY questions: What can I do to get ONLY one endpoint curve?  And what is the reaction of all components?

4,4'-Diamino diphenyl methane + 1-propanol + HNO3  >  .....

4,4'-Diamino diphenyl methane + HCL + 1-propanol + HNO3  > ....
Okay, clever ones   make my day..      MIND YOU the HCL will be in 2 - 10 ppm aswell as the added HNO3  !!!!

Titration is carried out with 1.0N KOH  !!