Organic micropollutants in Rhine and Meuse a - Riwa

Overlay at 215 nm
0,04
Meuse October 1997
spectrum Peak 5
0,03
~ 0,02
0,01
O+---~-----+---~-----+---~---+---~----+-------'--------1
o 10 20
retention time in minutes
30 40 50
Figure 8
HPLC/UVfingerprints ofthe October 1997 sample from the Meuse
and ofa standard solution of4.5 Jlg/l4,4'-dihydroxydiphenyl sulphone
in September 1998. It has now been established that the October 1997
sample contained approximately 4 Jlg/l ofthis compound. At the time,
the substance responsible for the peak had not been identified (and
was referred to as unidentified pollutant "peak 5").
4.6 Identification of unidentified peaks with HPLC/MS:
diethylphthalate and dibutylphthalate in the Rhine
In the Rhine sample from September, a large peak that had not been encountered in
earlier samples was measured at a retention time of approximately 32 minutes.
Application of the methods that at the time were being developed for identification of
unknown compounds with LC/MS (Bobeldijk, 1998) revealed that the peak was
diethylphthalate. In the same sample, another peak at a retention time of
approximately 47 minutes was identified as dibutylphthalate. The mass spectra are
given in Appendix 9.
Although both compounds can also be measured with GCIMS, the result also indicates
that the procedure followed, which comprises screening with HPLC/UV fingerprinting
with subsequent LCIMS identification of important peaks, can be successful for
monitoring of the water quality. This applies in this case all the more since the two
phthalates are xenoestrogenic compounds (Denneman, 1997). Dibutylphthalate is a
frequently occurring pollutant; diethylphthalate is encountered much less commonly.
In the framework of this project, no additional research for identification with LCIMS
was done for any other marked peaks.
20 RliliVA