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Development of Ultrasonic Assisted Extraction Method of Emerging
Contaminants in Freshwater Sediments
Diana Nara Ribeiro de Sousa1, Guilherme Martins Grosseli1, Mariele Barboni Campanha1, Renato
Lajarim Carneiro1, Antonio Aparecido Mozeto1, Pedro Sérgio Fadini1
1Universidade Federal de São Carlos – UFSCar, Rod. Washington Luís km 235, São
The determination of emerging
contaminants in water, soils, sediments, sludge and
suspended matter has become a requisite stage for the
partition evaluation of these contaminants. For
sediment samples, extraction methods include
microwave assisted extraction (MAE) and ultrasound assisted extraction (UAE). Among these, UAE has been shown very promising due to its lower cost,
easy processing and availability . In this work,
Observed recoveries values for the three
different procedures of extraction by ultrasound were
tested to extract 11 emerging contaminants.
In an attempt to increase the atenolol and propranolol
recoveries, it was investigated the effect of pH
Methanol, water, acetone, ethyl acetate
variation. Recoveries of propanolol and atenolol at
and different mixtures of these were used as
pH 2 were 70% and 2.6%, respectively (E3) and at
extraction solvents. Firstly, 2.00g of dry sediment,
pH 8 both compounds presented recoveries around
was spiked to 100 ng.g-1 with a solution containing
40% without compromising the quality of results.
all target compounds and respective deutered and
The exposition time to the ultrasound was optimized
submitted to successive steps of extraction in three
in 10 minutes and experiments at different levels of
different experiments. In the first one, samples were
spiking were performed with this time and pH 8.
ultrasonicated with 5 mL of methanol, 5 mL
methanol:water (1:1) and 2 mL of acetone
Observed recovery values at different levels
homogenized in vortex, ultrasonicated for 30 min and
centrifuged at 5000 rpm for 5 min. The supernatants
of each sample were combined, homogenized and
diluted to 250 mL with Milli-Q water. The other two
experiments involved differentiation with respect to
steps with 2 mL of ethyl acetate and 3 mL of
methanol:water (1:2, pH 2), respectively. The clean-
was carried out using Oasis HLB (200
mg, 6 cc) cartridges, conditioned with 2x5 mL of
methanol and 2x5 mL of Milli-Q water. After
extraction, cartridges were rinsed with 2x4 mL Milli-
Q water and dried for 30 min. Elution was performed
According to results, the developed
methanol:acetone (1:1). The extract was evaporated
methodology allows the simultaneous determination
under nitrogen stream and reconstituted with 1 mL of
of 11 emerging contaminants in freshwater sediments
methanol:water (25:75). Analyses were performed in
showing 9 recoveries values in accordance with the
a TQD Waters system. In the next stage, it was
Council Directive 96/23/EC and standard deviation
evaluated different ultrasound exposition times, the
lower than 10% in all the replicates, pointing the
influence of pH and recoveries values at three
potential applicability of the proposed method.
different levels of spiking (10, 50 and 100 ng.g-1).
The experiments E1 and E2 presented
recoveries values above 60% for all compounds
 Tadeo et al. (2012) Cent. Eur. J.
: 480-520 .
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