We have been using UHP He for years without any additional purification. We
use it on our two EA-IRMS and one Varian GC-MSMS. Once in a while (from on
supplier) there was a high Ar background in He. After we changed the
supplier, it has been fine for years.
Cheers 


On 11-06-08 8:57 PM, "Robert Van Hale" <[log in to unmask]>
wrote:

> Hi Brett,
> Probably not. And at that meagre price who would care. You guys just dig it
> out of the ground?
> 
> We use 4-9-8 (BOC "Zero Grade") straight out of the bottle for EA, gasbench
> and TCEA and I couldn't say that we have ever had problems related to gas
> purity. For the GC we have high capacity thermal purifier plus that Supelco
> 23800. I have no way of knowing if this does any good or if it gives any
> improvement in performance. We have not used oxygen-sensitive stationary
> phases or particularly water-sensitive either so do we need it? Reading the
> table of analysis from label on a He bottle: the principle contaminant is N2,
> then water, O2, Ar are the next most abundant all of which are either harmless
> or are seemingly produced in the source/prep system in far greater amounts.
> The only organic contaminant listed (ethane) being of low molecular weight
> would not affect chromatography(?), would merely add a baseline signal to CO2
> measurements.
> Lab Note - There is no bleed valve on our cylinder regulator so we have to
> fuss around cooling the heated trap and venting the line when changing the
> bottle, just to prevent the small slug of air from reaching the traps.
> All the best
> Robert
> 
> 
> -----Original Message-----
> From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
> Of Brett James Kuskopf
> Sent: Thursday, 9 June 2011 12:16 p.m.
> To: [log in to unmask]
> Subject: Re: [ISOGEOCHEM] purifier for He supply for IRMS
> 
> Great question, I'd appreciate some info on this as well.  I was wondering if
> there was an inline system capable of purifying 4.0 He (at AUD$45/G bottle) to
> 99.999% He as 5.0 He is AUD$170/G bottle.
> 
> Does anyone else do this?
> 
> Regards
> Brett 
> 
> -----Original Message-----
> From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf
> Of Shuangquan Zhang
> Sent: Thursday, 9 June 2011 10:05 AM
> To: [log in to unmask]
> Subject: [ISOGEOCHEM] purifier for He supply for IRMS
> 
> I am looking for the information on the purifier to work best for the He
> supply 
> line for an IRMS. Any information would be greatly appreciated.
> 
> Thanks,
> 
> Shuangquan Zhang
>