Isotopists,

Is there a maximum temperature that a Mg-perchlorate trap will work to 
effectively remove water in an He-continuous flow? In an EA, for example, 
can you pack the top of the copper reactor with Mg-perchlorate (well above 
the hot zone/furnace, and separated from the copper with quartz 
chips/quartz wool), rather than having a separate Mg-perchlorate trap prior 
to the GC. At first glance the only problem I can see is that the 
Mg-perchlorate will be hotter at that position than it would be later down 
the line, and maybe the trap is not effective at those temps. By touch, the 
outside temp of the quartz tube is ~50°C in the region I am talking about 
(maybe its hotter in the center of the tube?). Is there a flow concern I 
don't know about? I know this probably sounds like a really bad idea, so 
don't ask why I want to do such a thing. Briefly, I want to pass gas from 
my EA to a GCMSD setup, and want to minimize the number of fittings (i.e. 
leaks) that the Mg-perchlorate trap would present.

Toti