During a screening program conducted from 1995 to 1997 in Germany, 80 water bodies were analyzed, some regularly, some sporadically, for content of the neurotoxin anatoxin-a.
Analysis for the majority of the samples was differentiated between anatoxin-a contained in the cells and that dissolved in the water.
A total of 554 extracts (from 393 samples, many with analysis of seston as well as filtrate for differentiation of intra-and extracellular toxin content) were extracted with CH2Cl2and derivatized with pentafluorobenzylbromide for GC-ECD analysis with a detection limit of 2.5 x 10-4 mug L1.
Only 22% of all analyzed samples contained anatoxin-a, and the highest concentration found was 13.1 mug L- (the sum of the toxin in the cells and in the water).
If anatoxin-a was detected, it was usually found in the seston fraction, but only in some of the corresponding filtrates (with one exception, where it was detected only in the filtrate).
In these cases, concentrations were often even higher than in the seston.
The earliest occurrence of anatoxin-a during the year was in May and the latest in November.
Usually Anabaena and/or Aphanizomenon were present when anatoxin-a was found.
Mots-clés Pascal : Bloom, Concentration chimique, Etude comparative, Intracellulaire, Extracellulaire, Cyanobacteria, Bactérie, Anabaena, Aphanizomenon flosaquae, Neurotoxine, Allemagne, Europe, Belgique, Milieu eau douce, Lac artificiel, Toxine, Anatoxine
Mots-clés Pascal anglais : Bloom, Chemical concentration, Comparative study, Intracellular, Extracellular, Cyanobacteria, Bacteria, Anabaena, Aphanizomenon flosaquae, Neurotoxin, Germany, Europe, Belgium, Freshwater environment, Artificial lake, Toxin
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0327282
Code Inist : 002A05B10. Création : 16/11/1999.