Gerald,
We run freshwater POM filters quite regularly on our Costech-Delta V.  I 
have found that if samples have been acidified with HCl, the quartz insert 
and column takes a beating.  A plug of silver wool below the quartz wool in 
the insert helps.  I just run ~25 samples and change the insert to avoid 
deterioration in the columns.  Hope this helps.
Shapna

Water and Aquatic Sciences Research Program
University of Victoria, Department of Biology
PO Box 3020, Station CSC,
Victoria, BC, Canada V8W 3N5
(250) 472-4789
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www.uvic.ca/water


----- Original Message ----- 
From: "Gerard Olack" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, April 04, 2008 9:28 AM
Subject: [ISOGEOCHEM] filter problems


> Hi All--
>
> We've been running some filters samples on a Costech ECS4010--fresh water 
> phytoplankton.  Supposedly these are fresh water, no preservatives, and 
> filtered through standard glass fiber filters.  However we've had problems 
> with those samples eating holes in the quartz ash collector, the quartz 
> wool, and sometimes the quartz reactor tube too.  In the short term, extra 
> quartz wool and an extra quartz tube in the ash collector minimizes 
> damage.
>
> Has anyone else seen this, and if so, have you been able to trace the 
> source of the problems?  We've done other filter samples without unusual 
> problems.
> take care
>
> gerry
>