TOTAL LIPIDS IN PLS 10-12 FOR PESTICIDE ANALYSIS
From: Juan Martinez postlarmar@geo.net.co
To: shrimp@egroups.com
Sent: 4 July 2000
QUESTION:
I'm looking for the total lipids in Postlarvae 10-12. This is required
by the lab that is running the pesticide test on my PL's. I'm pretty sure
that my problem is pesticides. Is there any filtration system capable of
getting rid of them?
Juan Martinez
PostLarmar
E-mail: postlarmar@geo.net.co
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COMMENTS 1 :
It could well vary depending on the last feeding, considering this it
could be between 6 and 9% on dry weight basis. How do you know that they
are pesticides? Are you close to an agriculture area or so? Getting rid of
pesticides to a non affectable point is difficult and will depend on the
group (organo- N, P or Cl), pyrethroids, carbamates, etc. In general it
will be very, I mean very difficult to get rid of (search for ozone, pH to
break down the molecule)
Pablo Intriago
E-mail: aqualab1@ECUA.NET.ec
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COMMENTS 2 :
The lipid content of the post larvae will be dependent on what you are
feeding and the general condition of your postlarvae. It is
curious
that the analytical laboratory should require you to provide the
lipid
content of the larvae. Pesticide analysis is not dependent on
lipid
content although more fat may produce more bioaccumulated
pesticide. I would think the lipid content has to be analyzed
separately
for the same sample of larvae sent in for pesticide analysis. Good
quality activated charcoal works on many pesticides but has to be
monitored constantly to be sure it is still active. Ozone is
perhaps
the last resort measure as it is difficult to manage in seawater
without
creating toxicity within the salt chemistry. CHECK YOUR ALGAE for
bioaccumulation of low level and difficult to "catch"
pesticides.
Phil Boeing
E-mail:p.boeing@worldnet.att.net
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