Search found 3 matches

by White Rabbit
Thu Dec 17, 2015 4:35 am
Forum: Chromatography
Topic: Retention Times on PLOT columns
Replies: 1
Views: 5926

Retention Times on PLOT columns

We are seeing retention times shifting on our PLOT column even though we have ample flow on the nafion dryer and our dry gas source is bottled nitrogen which has both HC and moisture traps inline. The BP retention times are solid so I think it is related to moisture in the sample but not sure why. A...
by White Rabbit
Wed Dec 09, 2015 7:05 pm
Forum: Thermal Desorption
Topic: Recoveries of Light Gases
Replies: 1
Views: 13345

Recoveries of Light Gases

We have a problem with the recovery of light gases. Acetylene, Ethane, Ethylene and sometimes Propane. Since we use response factor from propane for all the targets on the PLOT column if the recovery is lower than it's supposed to be then the recoveries for C4 and C5 gases is higher than expected. H...
by White Rabbit
Tue Dec 08, 2015 9:41 pm
Forum: Chromatography
Topic: Problems with retention times on my BP column
Replies: 1
Views: 5149

Re: Problems with retention times on my BP column

Dear Hatter, Nice hair! It depends on just how bad they are changing and to some degree how old your system is. We generally look at the relative standard deviation (RSD) for each peak across the entire day and see only 0.02-0.03 on the BP column. Problems like leaks in the dean's switch or at the t...