Problem in Vinyl Chloride & Epichlorohydrin

[Davidantony]

Dear All
We are in the process of developing a method for VOCs according to 98/83 EC in our GCMS Agilent 7000B MSD & 7694E headspace sampler.All componds other than vinyl chloride and Epichlorohydrin achives the limit according to EC.We are using HP-5MS column and we are also tried it in DB-624.So if anyone doing this componds help us for reaching 0.1ppb for Epichlorohydrin and 0.5ppb for vinyl chloride.
One another problem Cary over of other compounds.So Help us how to avoid this

[rb6banjo]

Have you thought about exploring SPME as a means for concentrating the analytes instead of just relying on static headspace as a sampling method?

[Davidantony]

we are not thinking about SPME we are directly introduced sample directly.

[fsistere]

Hi
For volatile compounds use DB-624 column.
I analyse Vinyl Chloride by Head-space (syringe of combipal), but my limit is 1ppb. The problem is the low boiling point of Vinyl Chloride (problem to focalize the compund in the cap of column). If you inject in splitless you need to cryogenice to focalize it. You can try to inject in a low split (1:5), increment the velocity of injection (if you have syringe) to have a sharp peak.

[shiva_kant]

Dear fsistere
Thanks for your response for vinyl chloride but what about Epichlorohydrin and Cary over problem?

Using 1 mm Liner we can optimize our peak shape special early eluting analyte like vinyl chloride but in case of Epichlorohydrin we not getting response below 50 ppb by head space.

Low split increase moister content which directly heat loss of GC columns.

[fsistere]

Hi
I'm sorry but I don't analyze Epichlorohydrin.
Can you try Purge and trap? or another detector like ECD (Epichlorohydrin have a Cl)
In the MS your adquisition is SCAN or SIM?