Hello
I'm developing EPA 525.2 for my lab_ Regulated SemiVol. I have Agilent 5977/ EXTR source.
I'm using Agilent 8270D column(1.2 ml/min flow).
Inj:250C, Pulsed Splitless 50 psi until 1 min, flow to split 50 ml/min at 1 min
Oven:80_hold 0 min//25C/min_160C_hold 3 min//6C/min_312C_10min. I start at 80 because if my start point is lower I have every single peak fronting.
Transfer line 270C
I use extr tune file. Source 300/quad 150. Air/Water bellow 1%. Mass 45-500. Treshold 0.Scan speed 1.562(N=2). Gain factor 1. Solvent delay 4.20 min.
Solvent is ETOAC
I pass my Endrin and DDT breakdown(was 2% last injection) as long as separation.
Issues I have:
A lot of bleeding on the ETOAC solvent blk inj. All peaks are Mass 207 and/or 57. Sometimes it's more towards by the end of the run, sometimes it's all across the spec. Is it normal? I never worked with ETOAC before.

We were requested to go as low as 0.01 ppb for Endrin(which is 0.01 ppm on the column due to the sample volume of 1L), 0.02 ppb for Benzo(a)pyrene and Lindane, 0.04 ppb for Heptachlor and Heptachlor Epoxide, 0.07 Simazine. All others are 0.1 ppb. My instrument is not capable to see Endrin at 0.01 ppb as long as heptachlor and heptachloe epoxide at 0.04 ppb. The best I can do is 0.1 ppb(0.1 ppm on the column), maybe 0.07 ppb.
All other compounds are ok. I have nice RSD<18%
I've seen some people were able to go that low, but truly I don't know how?
Any ideas what can be done?
I was thinking to switch to EPA 525.3 which allows SIM mode.
Does anyone run EPA 525.2 or 525.3 with Endrin that low?
All calibration std are non procedural.
Thank you.