Chromatography Forum

dear all,

ihave problem in complete samples up to volume , ihave sample contain 3 active ingredient

and 2 of them pass the limit of acceptance criteria but the last one failed with result of 94.7%

and the acceptance criteria is 95% . all of these active were in the same dilution the same pippet

my diluent methanol&water 1:1.

may ihave answer for this mistakes.

Without knowing any of the details, I can only speculate:

The third compound was impure?

You weighed incorrectly?

The third compound is unstable in solution?

The third compound is only marginally soluble, and some precipitated before the dilution?

The third compound adsorbs onto glass surfaces?

The third compound peak was integrated incorrectly?

Is acceptance criteria 95% or 95.0%?

94.7% rounds to 95%, amount of significant figures is, well, significant...