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

METHOD OPTIMISATION
Fluidized bed extraction (FBE)
In order to determine the extraction efficiency of fluidized bed extraction (FBE, IKA GmbH,
Staufen, Germany) using hexane/acetone 1:1 (v:v). GFF (n=3) were folded and inserted into
glass tubes. Three extraction cycles of 30 min with a maximum temperature of 75 °C, hold for
30 min, were used. After each cycle, solvent was allowed to cool down to 30 °C. Extracts
were evaporated to 1 mL using a synchore polyvap and further reduced to 150 μL with
nitrogen. Final extracts were transferred to GC vials and determined by GC-MS. Prior to the
measurements, 50 μL of an injection standard solution ( 13 C HCB and Fluoranthene D10,
c=400 pg μL -1 ) was added to the samples. According to DIN 32645 (1994) linearity of a
seven point calibration curve (2, 4, 10, 20, 50, 80, 100, 200 pg μL -1 ) was tested. Peaks were
quantitated by peak area and calculated with the internal standard method.
3.2.7 Clean-up of PBDEs in the particle phase
Eight air samples were taken at GKSS for one day each using high volume samplers. GFF
(150 mm in diameter) were extracted with ASE using the method described in section 3.2.6.
The extracts were combined and used for the purification experiments (n=2). Prior to the
clean-up, 60 mL of the combined extract were evaporated to about 1 mL and used as
reference material for the tests. Clean-up of the extracts was performed using the method of
Kaupp for PAH from aerosols (Kaupp 1996). 5 g of silica gel (0 % deactivated) was filled in a
glass column (d = 1 cm) and covered by 3 g aluminium oxide (15 % deactivated). Hexane was
added for equilibration. Evaporated extracts were transferred to the glass columns and eluted
with 35 mL hexane (fraction 1) and 30 mL hexane/dichloromethane 3:1 (v:v) (fraction 2).
Finally, the different fractions were rotary evaporated at 30 °C and 240 mbar to about 1 mL,
and further reduced to 150 μL using nitrogen and transferred to GC vials. Prior to the
measurements using GC-MS, 50 μL of an injection standard solution ( 13 C HCB and
Fluoranthene D10, c=400 pg μL -1 ) was added to the samples. For quantification a seven point
calibration was used (2, 4, 10, 20, 50, 80, 100, 200 pg μL -1 ). Linearity of calibration was
checked according to DIN 32645 (1994). Peaks were quantitated based on their peak area and
calculated using the internal standard method.
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