by the continuous inflow of racemic material. In addition, the biological activity may
have been larger during the summer months, which may also have given rise to a
more intense enantioselective discrimination. Similar to the values for 1,3,2
0 ,30 -Cl 4 BPE, the ER values for the samples “Magdeburg”, “Zollenspieker” and
“Grauerort” were in the range of the racemate, considering the variability of the
method. Again, the sample “Cuxhaven” with an ER value far above 1 deviates
significantly from the other samples. The corresponding concentration was relatively
high, but Franke et al. could not offer a scientifically convincing explanation for this
observation (Fig. 8.10).
In the following years, in line with the continuous progress of trace analytical
methods, technology and research focus in the field of enantiomer-selective trace
analysis of chiral organic pollutants; the list of target substances continuously
increased. Due to conscious environmental screening, a new environmental contaminant, the insecticide bromocyclen (CAS 1715-40-8), was identified in biota
(Pfaffenberger et al. 1994a, b; Bethan et al. 1997). This brominated and chlorinated
bicycloheptene contact insecticide (tradename Bromodan
® , Alugan
® ) is the DielsAlder adduct of hexachlorocyclopentadiene and allyl bromide. It possesses neither a
plane nor a centre of symmetry, and therefore, it exists in two enantiomeric forms
(Fig. 8.11).
Fig. 8.10 Sampling sites P1–P9 along the Elbe River (Northern Germany) during the campaign
carried out by Franke et al. (1998)
128
8 Enantiomer-Specific Fate and Behaviour of Chiral Contaminants
have been larger during the summer months, which may also have given rise to a
more intense enantioselective discrimination. Similar to the values for 1,3,2
0 ,30 -Cl 4 BPE, the ER values for the samples “Magdeburg”, “Zollenspieker” and
“Grauerort” were in the range of the racemate, considering the variability of the
method. Again, the sample “Cuxhaven” with an ER value far above 1 deviates
significantly from the other samples. The corresponding concentration was relatively
high, but Franke et al. could not offer a scientifically convincing explanation for this
observation (Fig. 8.10).
In the following years, in line with the continuous progress of trace analytical
methods, technology and research focus in the field of enantiomer-selective trace
analysis of chiral organic pollutants; the list of target substances continuously
increased. Due to conscious environmental screening, a new environmental contaminant, the insecticide bromocyclen (CAS 1715-40-8), was identified in biota
(Pfaffenberger et al. 1994a, b; Bethan et al. 1997). This brominated and chlorinated
bicycloheptene contact insecticide (tradename Bromodan
® , Alugan
® ) is the DielsAlder adduct of hexachlorocyclopentadiene and allyl bromide. It possesses neither a
plane nor a centre of symmetry, and therefore, it exists in two enantiomeric forms
(Fig. 8.11).
Fig. 8.10 Sampling sites P1–P9 along the Elbe River (Northern Germany) during the campaign
carried out by Franke et al. (1998)
128
8 Enantiomer-Specific Fate and Behaviour of Chiral Contaminants