>
> >Ghislain De Roeck,
>


> See: http://www.cabdirect.org/abstracts/20083103467.html (Bees and
> systemic
> insecticides (imidacloprid, fipronil) in pollen: subnano-quantification by
> HPLC/MS/MS and GC/MS).
>

Abstract from the above (just in case someone miss it )...

Imidacloprid and fipronil are two insecticides acting on the central nervous
system. They are used worldwide, from the mid nineties, especially for seed
coating of crops. Concomitantly to their introduction and their increasing
use in French fields, honeybee populations decreased. Bee problems are
nowadays reported in other countries (also called *disappearing
disease*, *desplobación
de las colmenas*, *trouble des abeilles*,*deperimento degli apiari* or *colony
collapse disorder*). Bee problems have certainly several origins.
Contamination of pollen and nectar by such chemicals appeared as one of the
most probable cause, since sublethal effects and chronic intoxications were
observed on bees, at very low concentrations. We developed fully validated
methods to measure contamination in pollen (sunflower and maize) for
imidacloprid (HPLC/MS/MS) and for fipronil and 3 of its derivatives (GC/MS).
For imidacloprid LOD and LOQ are 0.3 and 1 ng/g, respectively. For fipronil
and each derivative (fiprole), LOD and LOQ are 0.07 and 0.2 ng/g,
respectively. The averaged level of imidacloprid in pollen was 2-3 ng/g,
which is 20-30 times higher than the concentration inducing significant
mortality by chronic intoxication. Fiproles were detected in 48% of pollens
issuing from treated crops. Fipronil and its sulfone derivative represented
77% and 17% of contaminants, respectively. The averaged fiprole sum Σf was
0.3-0.4 ng/g, which is 30-40 times higher than the concentration inducing
significant mortality of bees by chronic intoxication



> --

Juanse Barros J.
APIZUR S.A.
Carrera 695
Gorbea - CHILE
+56-45-271693
08-3613310
http://apiaraucania.blogspot.com/
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