Ô Springer
Environ Sci Pollut Res (2015) 22:19887-19895
DOI 10.1007/s 11356-015-5192-1
RESEARCH ARTICLE
Accelerated solvent extraction (ASE)
for purification and extraction of silicone passive samplers
used for the monitoring of organic pollutants
Berit Brockmeyer * 1 • Uta R. Kraus 1 • Norbert Theobald 1
Received: 18 March 2015 /Accepted: 10 August 2015 /Published online: 21 August 2015
© The Author(s) 2015. This article is published with open access at Springerlink.com
Abstract Silicone passive samplers have gained an increasing
attention as single-phased, practical and robust samplers
for monitoring of organic contaminants in the aquatic environment
in recent years. However, analytical challenges arise in
routine application during the extraction of analytes as silicone
oligomers are co-extracted and interfere severely during
chemical analyses (e.g. gas chromatographic techniques). In
this study, we present a fast, practical pre-cleaning method for
silicone passive samplers applying accelerated solvent extraction
(ASE) for the removal of silicone oligomers prior to the
water deployment (hexane/dichloromethane, 100 °C, 70 min).
ASE was also shown to be a very fast (10 min) and efficient
extraction method for non-polar contaminants (non-exposed
PRC recoveries 66-101 %) sampled by the silicone membrane.
For both applications, temperature, extraction time
and the solvent used for ASE have been optimized. Purification
of the ASE extract was carried out by silica gel and highpressure
liquid size exclusion chromatography (HPLC-SEC).
The silicone oligomer content was checked by total reflection
X-ray fluorescence spectroscopy (TXRF) in order to confirm
the absence of the silicone oligomers prior to analysis of passive
sampler extracts. The established method was applied on
real silicone samplers from the North- and Baltic Sea and
showed no matrix effects during analysis of organic pollutants.
Internal laboratory standard recoveries were in the same
range for laboratory, transport and exposed samplers (85-126
%).
Responsible editor: Philippe Garrigues
G3 Berit Brockmeyer
berit.brockmeyer@bsh.de
1 Federal Maritime and Hydrographic Agency (BSH),
Bemhard-Nocht-Str. 78, 20359 Hamburg, Germany
Keywords Silicone passive sampler • Pressurized liquid
extraction • Accelerated solvent extraction •
Polydimethylsiloxane • TXRF • Size exclusion
chromatography (HPLC-SEC)
Introduction
Passive sampling, as time integrated sampling approach, is
increasingly used for monitoring of organic contaminants in
the water phase providing a cost-efficient alternative to active
water sample collection. The basic principle of this sampling
method is the passive diffusion and absorption of hydrophobic
contaminants from the water phase into the sampler. A large
variety of non-polar samplers have been applied so far, among
those are semi-permeable membrane devices, low-density
polyethylene (LDPE) strip samplers and polydimethylsiloxane
(PDMS) strip samplers (Vrana et al. 2005).
Common characteristics of single-phased passive strip
samplers are their simple construction, low costs and the possibility
for re-use (Rusina et al. 2007). PDMS strip samplers
are often the samplers of choice, because polymer-water partition
coefficients (A' pw ) for many contaminants have been
reported in the literature (Smedes et al. 2009). Furthermore,
PDMS samplers can absorb chemicals with a wider log K Qw
range than LDPE strips. In a current comparison study, Allan
et al. (2013) tested PDMS and LDPE strips for the screening
of a wide range of chemicals and showed that PDMS is less
discriminating than LDPE with regard to more polar substances
such as organophosphate compounds (OPCs). PDMS
samplers have been successfully applied for the monitoring of
polycyclic aromatic hydrocarbons (PAHs), polychlorinated
biphenyls (PCBs), hexachlorobenzene (HCB) as well as
OPCs in both, limnic and marine waters (Smedes 2007;
Schafer et al. 2010; Allan et al. 2013).
