120% recovery for LOQ (Matrix effect)
Posted: Wed Feb 13, 2019 4:48 pm
Has anyone observed a matrix effect occur only at the LOQ? Background: I made a GC method of aniline (actually aniline.HCl since our compound is an HCl salt). At the LOQ I get a 120% recovery of aniline, but at other points, I get 98% recovery. Besides potential error, what could cause this?
Note: Standard prep is in MeOH alone while the sample prep involves quantitative addition of NaOH to convert to plain aniline from HCl salt. I have also observed that addition of a small amount of NaCl to standard boosts the aniline response, but only at the LOQ point. What gives?
Note: Standard prep is in MeOH alone while the sample prep involves quantitative addition of NaOH to convert to plain aniline from HCl salt. I have also observed that addition of a small amount of NaCl to standard boosts the aniline response, but only at the LOQ point. What gives?