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Landfills and waste water treatment plants as sources of ... - GKSS

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METHOD OPTIMISATION<br />

Figure 6: Improvements <strong>of</strong> sensitivity (%) <strong>of</strong> PBDEs <strong>and</strong> musk fragrances after optimisation <strong>of</strong><br />

PTV inlet on the b<strong>as</strong>is <strong>of</strong> previous PTV inlet settings in section 3.2.2<br />

Further objective w<strong>as</strong> the optimisation <strong>of</strong> an instrumental method that is sensitive for PBDEs<br />

<strong>and</strong> musk fragrances. Due to the high LOD <strong>and</strong> LOQ in the EI mode for higher brominated<br />

PBDE congeners it w<strong>as</strong> not possible to determine these compounds at low concentration<br />

levels. Thus the objective to develop a simultaneous detection method w<strong>as</strong> not achieved <strong>and</strong><br />

NCI mode w<strong>as</strong> selected <strong>as</strong> the adequate ionisation mode for PBDEs. For further analysis,<br />

PBDEs had to be separately determined in the NCI mode <strong>and</strong> musk fragrances in the EI<br />

mode. Finally, following optimized inlet parameter were used: Initial inlet temperature 70 °C,<br />

initial oven temperature 60 °C, final inlet temperature 300 °C, inlet heating rate 400 °C, initial<br />

oven temperature: 60 °C. Final optimized oven temperature programs <strong>and</strong> final<br />

chromatograms are displayed in table 15 <strong>and</strong> figure 7, respectively.<br />

Table 15: Final oven temperature programs for the determination <strong>of</strong> PBDEs <strong>and</strong> musk<br />

fragrances using GC-MS<br />

NCI (PBDEs)<br />

EI (Musk fragrances)<br />

heating rate final temperature hold time heating rate final temperature hold time<br />

°C min -1 °C min °C min -1 °C min<br />

30 130 0 30 130 0<br />

5 170 3 5 170 3<br />

5 200 0 5 200 0<br />

15 300 20 15 300 5<br />

41

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