Thanks all (on and off line replies)

gerry

p.s.  I'm guessing the samples here are being treated somewhere along 
the way, hence the problems.

Shapna Mazumder wrote:
> 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
> [log in to unmask]
> 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
>>
>