-
- Posts: 1
- Joined: Thu Apr 02, 2020 6:04 pm
I'm running EPA 524.2 method and have and issue. I'm making 50 ppm intermediate standards - one for gases (dichlorodifluoromethane, chloromethane, vinylchloride, bromomethane, chloroethane, trichlorofluoromethane) and another for other 524.2 compounds
I have made new intermediates on 2/19 and calibrated the instrument. The intermediate standards are stored in the freezer.
With every run I have been running a 5 ppb check made from the same intermediates.
First 2 runs are of my 5 ppb check are great - everything passes (ie recoveries are within 70-130 %)
but now my gases are failing badly. They are at about 50% recovery. I'm trying to figure out what the problem could be as it is the 1st time I'm having issue with this.
I'm running the analysis using purge and trap system with the K trap from Tekmar.
Any advice will be appreciated.