Analytica Chimica Acta 770 (2013) 68–74
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Analytica Chimica Acta
jo u rn al hom epa ge: www.elsevier.com/locate/aca
Polythiophene-coated Fe
3
O
4
superparamagnetic nanocomposite:
Synthesis and application as a new sorbent for solid-phase extraction
Elham Tahmasebi, Yadollah Yamini
∗
, Morteza Moradi, Ali Esrafili
Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran
h i g h l i g h t s
◮ A novel polythiophene-coated Fe
3
O
4
nanoparticles (Fe
3
O
4
@PTh NPs) was
synthesized.
◮ The synthesized Fe
3
O
4
@PTh NPs
were characterized by using differ-
ent instruments.
◮ The Fe
3
O
4
@PTh NPs were applied as a
sorbent for extraction of several plas-
ticizers.
◮ After extraction, separation of NPs
from solution was achieved by a
magnetic field.
◮ The proposed procedure was applied
to analysis of the analytes in real
water samples.
g r a p h i c a l a b s t r a c t
In the present work, polythiophene-coated Fe
3
O
4
nanoparticles (Fe
3
O
4
@PTh NPs) have been successfully
synthesized. The synthesized Fe
3
O
4
@PTh NPs were applied as an efficient sorbent for extraction and
pre-concentration of several typical plasticizer compounds from environmental water samples.
a r t i c l e i n f o
Article history:
Received 4 October 2012
Received in revised form 20 January 2013
Accepted 22 January 2013
Available online 29 January 2013
Keywords:
Polythiophene-coated Fe3O4 magnetic
nanoparticles
Magnetic separation
Phthalates
Gas chromatography–flame ionization
detector
Solid-phase extraction
a b s t r a c t
In the present work, a novel type of superparamagnetic nanosorbent, polythiophene-coated Fe
3
O
4
nanoparticles (Fe
3
O
4
@PTh NPs), have been successfully synthesized. The synthesized NPs were char-
acterized by scanning electron microscopy (SEM), Fourier transform-infrared (FT-IR) spectroscopy,
and thermal gravimetric analysis (TGA). The synthesized Fe
3
O
4
@PTh NPs were applied as an efficient
sorbent for extraction and preconcentration of several typical plasticizer compounds (di-n-butyl phtha-
late (DBP), di-(2-ethylhexyl) phthalate (DEHP), and dioctyl adipate (DOA)) from environmental water
samples. Separation of Fe
3
O
4
@PTh NPs from the aqueous solution was simply achieved by applying
external magnetic field. Separation and determination of the extracted plasticizers was performed by
gas chromatography–flame ionization detection (GC–FID). Several variables affecting the extraction effi-
ciency of the analytes i.e., amount of NPs sorbent, salt concentration, extraction time, and desorption
conditions were investigated and optimized. The best working conditions were as follows: amount of
sorbent, 100 mg; NaCl concentration, 30% (w/v); sample volume, 45 mL; extraction time, 10 min; and
100 L of ethyl acetate for desorption of the analytes within 2 min. Under optimized conditions, precon-
centration factors for DBP, DEHP, and DOA were obtained as 86, 194, and 213, respectively. The calibration
curves were linear (R
2
> 0.998) in the concentration range of 0.4–100 g L
-1
for both DEHP and DOA and
0.7–100 g L
-1
for DBP. The limits of detection (LODs) were obtained in the range of 0.2–0.4 g L
-1
. The
intra-day relative standard deviations (RSDs%) based on four replicates were obtained in the range of
4.0–12.3%. The proposed procedure was applied to analysis of water samples including river water, bot-
tled mineral water, and boiling water exposed to polyethylene container (after cooling) and recoveries
between 85 and 99% and RSDs lower than 12.8% were obtained.
© 2013 Elsevier B.V. All rights reserved.
∗
Corresponding author. Tel.: +98 21 82883417; fax: +98 21 88006544.
E-mail address: yyamini@modares.ac.ir (Y. Yamini).
0003-2670/$ – see front matter © 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.aca.2013.01.043