19894
Environ Sci Pollui Res (2015) 22:19887-19895
Ф Springer
corresponding lab and transport blanks. In general, PAH recovery
was good, while 2- and 3-ring aromatic PAHs showed
lower recoveries than PAHs with higher aromatic rings.
The recovery rates of PRCs in laboratory blanks can be
additionally used for QA/QC issues, for example, to ensure
a successfi.il spiking procedure and storage. The recovery rates
of PRCs determined in laboratory blanks ranged from 66 to
101 % demonstrating that the used spiking procedure was
successful for most of the CHCs and PAHs. Due to its
physico-chemical properties, y-HCH- 13 C 6 showed the lowest
recovery as this analyte might be already equilibrated with the
water phase during spiking, supported by the fact that the
corresponding internal standard e-HCH. representing the extraction
efficiency, showed good recoveries (87 %).
Overall, the results of the recovery rates proofed that matrix
of deployed samplers does not affect extraction and purification
as well as that the used procedure is reliable for PDMS
extraction, avoiding the interference of silicone oligomers during
mass spectrometric analysis. Full-scan MS measurements
revealed no additional background peaks which could be related
to silicone oligomers.
CHC and PAH concentration
At the stations Fehmam and Heligoland CHC and PAH concentrations
in the water phase were estimated according to the
method of Smedes and Booij (2012). Briefly, the proportionality
constant B was calculated by a nonlinear least square
regression calculated by the PRC fractions retained in the
exposed sampler compared with the control sampler versus
log(Ap W M 0 47 ) as presented in Fig. 6a. The proportionality
constant B was then used to estimate the specific sampling rate
which is necessary to calculate the water phase concentrations
of the target compounds.
Heligoland represents a marine station while Fehmam
represents a brackish water station. Thus, as expected,
Fehmam waters generally show higher analyte concentrations
than Heligoland waters (Fig. 6b, c). The concentrations
of individual CHCs were between 6-54 and 0.4-18
pg/L for Fehmam and Heligoland, respectively, with
hexachlorobenzene having the highest concentration. The
concentrations of individual PAHs ranged from 3-7145 and
1-2750 pg/L for Fehmarn and Heligoland, respectively.
Phenanthrene, fluorene and fluoranthene have the highest
concentration within the measured PAH compounds. The
more hydrophobic PAHs (e.g. indenopyrene) have minor
concentrations. In general, the concentrations are in the
same range and show the same compound patterns and proportions
compared to active water samples of routine monitoring
operated by the BSH (Loewe et al. 2013; MURSYS
2011). Hence, PDMS sampler deployment and extraction as
described in this study is suitable for routine monitoring of
non-polar organic contaminants in brackish and seawater.
Conclusions
The method presented improves handling and use of silicone
rubber sheets for passive sampling in several aspects: (1) ASE
for pre-cleaning and extraction, (2) HPLC-SEC for the removal
of residual silicone oligomers and (3) control of oligomers
by TXRF.
ASE can perform pre-cleaning and extraction in a fraction
of time and with much less solvent compared to other extraction
procedures, such as Soxhlet. Furthermore, non-polar extraction
solvents show better extraction efficiencies and higher
analyte recoveries than polar solvents. In combination with
HPLC-SEC as additional sample extract purification procedure,
residual silicone oligomers can be removed before the
determination of non-polar compounds. By monitoring the
silica content in the extract with TXRF, interferences of chemical
analysis can be avoided. The entire method was successfully
applied on deployed marine sampler. In conclusion, this
study optimized the preparation as well as extraction and purification
procedure of PDMS samplers in order to enable
silicone passive samplers more favourable and robust for routine
monitoring of contaminants in the water phase.
Acknowledgement This work was part of the NOAH project funded
by the German Federal Ministry of Education and Research (No.
03F0670A). We are grateful to Ms. A. Neubauer-Ziebarth and Ms. I.
Raschke for their help in performing the TXRF measurements.
Open Access This article is distributed under the terms of the Creative
Commons Attribution 4.0 International License (http://
creativecommons.org/licenses/by/4.0/), which permits unrestricted use,
distribution, and reproduction in any medium, provided you give appropriate
credit to the original authorf s) and the source, provide a link to the
Creative Commons license, and indicate if changes were made.
References
Allan IJ, Harman C, Ranneklev SB, Thomas KV, Grung M (2013)
Passive sampling for target and nontarget analyses of moderately
polar and nonpolar substances in water. Environ Tox Chem 32(8):
1718-1726. doi:10.1002/etc.2260
Ezzell J, Richter В (2012) Extraction of PCBs from environmental samples
using accelerated solvent extraction. Application note, Thermo
Fisher Scientific., p 316
Loewe P, Klein H, Weigelt-Krenz S (2013) System North Sea-2006 &
2007: status and trends. Berichte des BSH 49, Bundesamt fiir
Seeschifffahrt und Hydrographie. Hamburg und Rostock, German
MURSYS (2011) Regional distribution of organic contaminants in the
pélagial and the surface sediment of the Baltic in 2011. Marine
environment reporting system Germany., http://www.bsh.de/
Vorlagen/ressources/Druckversion.jsp?_PRINTPAGE_=yes&_
PRINTOID_= 146351 & Accessed 16 March 2015
O'Connell SG, McCartney MA, Paulik LB, Allan SE, Tidwell LG,
Wilson G, Anderson KA (2014) Improvements in pollutant monitoring:
optimizing silicone for co-deployment with polyethylene
passive sampling devices. Environ Poll 193:71-78. doi: 10.1016/j.
envpol.2014.06.019
