Hi Anne,

We collect snow routinely for isotope analysis (originally on a mass 
spec, now on the Picarro).  Our field guy collects fresh snow weekly 
from flat platforms (usually just plywood on a stand in the open) 
into a 3" diameter jar with a tight lid.  He brushes off the rest of 
the snow so the platform only collects fresh snow.  The sample is put 
in a refrigerator to thaw overnight and then poured into exetainer 
vials and capped and put back into the refrigerator until 
analysis.  I use the exetainer vials because it has a tight-fitting 
cap, and because I can fill it to the top to eliminate air 
space.  This method has worked well for the last 5 years.  For the 
Picarro, be careful that the sample doesn't have any particles in it 
that might foul the needle.  You should be able to see anything that 
would cause a problem.  Taking the sample from the very top of the 
exetainer works, but you could also filter the snow water into the 
exetainer through quartz wool.

Any method that 1) only collects current snow, 2) keeps the snow 
contained as it thaws and 3) keeps the melt water from evaporating 
until analysis, should be fine.

I like snow.  It's easy.

Lola.


.

At 01:22 AM 1/22/2010, you wrote:
>Hello,
>
>I will be collecting snow samples for water isotope analyses using a 
>Picarro instrument. I would appreciate information on what sort of 
>sample vials to use and any additional information on snow sample 
>collection techniques.
>
>Thank you,
>Anne
>
>************************************************
>Anne Nolin
>Landolt et Cie Chair for Sustainable Futures, Ecole Polytechnique 
>Federale de Lausanne and
>Associate Professor, Department of Geosciences
>Wilkinson 104
>Oregon State University
>541-737-8051 (office)
>541-737-1200 (fax)
>http://www.geo.oregonstate.edu/people/faculty/nolina.htm
>[log in to unmask]
>skype: AnneNolin; 541-497-7213
>************************************************