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Autori: Ionel Ciucanu, Vlad Agotici
Editorial: Wiley, Journal of Separation Science, 35 (13), p.1651-1658, 2012.
A new technique for the analysis of volatile aromatic hydrocarbons by combining liquid–
liquid microextraction with solid phase microextraction has been developed. The analytes
were extracted from aqueous samples by an immobilized polydimethylsiloxane fiber assisted
by the droplets of an appropriate organic solvent. Benzene, toluene, ethylbenzene,
and o-xylene were used as target analytes. The main factors potentially affecting the microextraction
such as the nature and the volume of organic solvent, polydimethylsiloxane
(PDMS) swelling, extraction time, agitation, temperature, and salts were optimized. The
method requires a very low consumption of organic solvent. The relative enrichment factor
is in the range of 7.1–32.4 for extraction in the presence of dichloromethane at an optimum
volume of 18 mcL/mL of aqueous sample. This enhancement over regular polydimethylsiloxane
fiber is primarily the result of the fiber swelling and of a stable thin layer of organic
solvent attached to the surface of the PDMS fiber. The limit of detection ranges from 0.02 to
0.65 ng/mL for the target compounds using a 7-mcm bonded polydimethylsiloxane coating
and a flame ionization detector. The validity of this method is demonstrated by the analysis
of a real waste water sample.
Cuvinte cheie: droplets based liquid-liquid microextraction, gas chromatography, solid phase microextraction, volatile aromatic hydrocarbons, water analysis