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 increas 
ing attention as single-phased, practical and robust samplers 
for monitoring of organic contaminants in the aquatic environ 
ment in recent years. However, analytical challenges arise in 
routine application during the extraction of analytes as sili 
cone 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 extrac 
tion (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 mem 
brane. For both applications, temperature, extraction time 
and the solvent used for ASE have been optimized. Purifica 
tion of the ASE extract was carried out by silica gel and high- 
pressure 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 pas 
sive 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 pollut 
ants. 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 polydimethylsilox 
ane (PDMS) strip samplers (Vrana et al. 2005). 
Common characteristics of single-phased passive strip 
samplers are their simple construction, low costs and the pos 
sibility for re-use (Rusina et al. 2007). PDMS strip samplers 
are often the samplers of choice, because polymer-water par 
tition 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 sub 
stances 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).