REMOVAL OF CAFFEINE FROM WATER SOURCES USING …
1
CHARACTERIZATION APLICATION According to the United States Environmental Protection Agency (USEPA), emerging contaminants are defined as chemical compounds that can enter the environment with human health impacts that are still unknown 1 . Caffeine (CF) is a psychoactive substance widely consumed both, in naturally occurring products such as tea, coffee, cocoa, and in artificial products, such as energy drinks. It is also used as active ingredient of pharmaceuticals of massive used. The synthesis of new materials for CF adsorption/desorption is of great interest for its removal from water sources. There are some reports about the use of carbonaceous solid materials in combination with the biopolymer alginate in pollutant removal studies 2 , but its application in columns is scarce. In this sense, the present work proposes the synthesis and characterization of alginate/carbon nanotubes (AB/NTCs) composite beads and the implementation of these materials in an adsorption/desorption minicolumn for the removal of CF. NTC + ALG BEADS SIMPLE AUTOMATED SYSTEM SYNTHESIS For the synthesis of the AB/NTCs, a suspension was prepared by dispersing the NTCs in 1% w/v deionized water using ultrasound for 2 h. At the same time, a solution containing 1% w/v alginate in deionized water was prepared and kept under constant stirring for 2 h. After homogenization of the alginate, the NTCs suspension was added. The beads were formed in a 0.1 M calcium chloride solution. The beads were characterized by scanning electron microscopy, digital photography, and infrared spectroscopy. A simple automated system was designed to carry out the adsorption and desorption of CF. For this, beads were packed in a minicolumn (3.0 x 0.5 cm i.d.). A 1 mg L -1 solution of CF was passed through the minicolumn at a flow rate of 0.50 mL min -1 , and then acetonitrile was used to perform the desorption. Quantification of CF was performed by UV-Vis. Preliminary tests showed that the NTCs encapsulated in the alginate beads facilitate the adsorption and subsequent desorption of CF by solving problems of overpressure and agglomeration in the column. The characterization of the PA/NTC allowed us to determine that in the synthesis of the material the NTCs are incorporated both on the surface and inside the bead. Table 1. ADSORPTION/DESORPTION PROCEDURE VOLUME (mL) 1. MeOH (minicolumn conditioning ) 3.0 2. WATER 3.0 3. SAMPLE (Adsorption) 100.0 4. WATER 2.0 5. ELUENT (desorption) 2.0 The adsorption and subsequent desorption process used is shown in Table 1. The experimental conditions were optimized and are shown in Table 2. Measurements were carried out on a UV-Vis-DAD spectrometer at 273 nm. VARIABLE OPTIMUM Sorbent Graphene / Carbon Nanotubes / C18 / Carbon Nanofibers / PA-NTC PA-NTC Eluent ACN 90%-H 2 O 10%/ ACN/ MeOH ACN Eluent volume 0.5-4.0 mL 2.0 mL Sample volume 5.0-150.0 mL 100.0 mL Sample flow rate (0.25-0.77) mL min -1 0.67 mL min- 1 Eluent flow rate (0.20- 0.67) mL min -1 0.25 mL min -1 Table 2. Optimized parameters Figure 1. FTIR spectrum a) calcium alginate beads (AB) b) carbon nanotubes (NTC) c) alginate beads / carbon nanotubes (AB/NTC). Figure 2. Digital photography a) AB / NTC wet, b) AB / NTC dry (a) (b) Figure 3. Scanning electron microscopy (SEM) a) carbon nanotubes (NTC) b) alginate bead c) interior of alginate bead d) NTC beads e) and f) interior of NTC beads. (a) (b) (c) (d) (e) (f ) Currently, we are working in the determination of CF in surface water samples, and the possible interferents that these samples may contain. Acknowledgment : ANPCYT, CONICET and SECYT-UNS for the funding [1] K. Vargas-Berrones, L. Bernal-Jácome, L. Díaz de León-Martínez, R. Flores Ramírez. Sci. Total Environ., 726 (2020), p. 138493 [2] H.B. Quesada, T.P. de Araújo, D.T. Vareschini, M.A.S.D. de Barros, R.G. Gomes, R. Bergamasco,Int. J. Biol. Macromol. 164 (2020) 2535–2549. REFERENCES INTRODUCTION REMOVAL OF CAFFEINE FROM WATER SOURCES USING ALGINATE/CARBON NANOTUBES BEADS Orduz Angie *, González Natalia, Acebal Carolina, Zanini Graciela. INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Buenos Aires, Argentina, 8000 * e-mail: [email protected] METHODS AB/NTCs RESULTS AND DISCUSSION CONCLUSION This kind of minicolumns are also useful to extraction system and preconcentration to improve CF quantification
Transcript of REMOVAL OF CAFFEINE FROM WATER SOURCES USING …
CHARACTERIZATION APLICATION
According to the United States Environmental Protection Agency
(USEPA), emerging contaminants are defined as chemical
compounds that can enter the environment with human health
impacts that are still unknown1. Caffeine (CF) is a psychoactive
substance widely consumed both, in naturally occurring products
such as tea, coffee, cocoa, and in artificial products, such as energy
drinks. It is also used as active ingredient of pharmaceuticals of
massive used.
The synthesis of new materials for CF adsorption/desorption is of
great interest for its removal from water sources. There are some
reports about the use of carbonaceous solid materials in combination
with the biopolymer alginate in pollutant removal studies2, but its
application in columns is scarce.
In this sense, the present work
proposes the synthesis and
characterization of alginate/carbon
nanotubes (AB/NTCs) composite
beads and the implementation of
these materials in an
adsorption/desorption minicolumn
for the removal of CF.
NTC + ALG BEADS
SIMPLE AUTOMATED SYSTEM
SYNTHESIS
For the synthesis of the AB/NTCs, a suspension was prepared by
dispersing the NTCs in 1% w/v deionized water using ultrasound for
2 h. At the same time, a solution containing 1% w/v alginate in
deionized water was prepared and kept under constant stirring for 2 h.
After homogenization of the alginate, the NTCs suspension was
added. The beads were formed in a 0.1 M calcium chloride solution.
The beads were characterized by scanning electron microscopy,
digital photography, and infrared spectroscopy. A simple automated
system was designed to carry out the adsorption and desorption of
CF. For this, beads were packed in a minicolumn (3.0 x 0.5 cm i.d.).
A 1 mg L-1 solution of CF was passed through the minicolumn at a
flow rate of 0.50 mL min-1, and then acetonitrile was used to perform
the desorption. Quantification of CF was performed by UV-Vis.
Preliminary tests showed that the NTCs encapsulated in the alginate beads facilitate
the adsorption and subsequent desorption of CF by solving problems of overpressure
and agglomeration in the column.
The characterization of the PA/NTC allowed us to determine that in the synthesis of
the material the NTCs are incorporated both on the surface and inside the bead.
Table 1. ADSORPTION/DESORPTION PROCEDURE
VOLUME (mL)
1. MeOH (minicolumn conditioning ) 3.0
2. WATER 3.0
3. SAMPLE (Adsorption) 100.0
4. WATER 2.0
5. ELUENT (desorption) 2.0
The adsorption and
subsequent desorption process
used is shown in Table 1. The
experimental conditions were
optimized and are shown in
Table 2. Measurements were
carried out on a UV-Vis-DAD
spectrometer at 273 nm.
VARIABLE OPTIMUM
Sorbent
Graphene / Carbon
Nanotubes / C18 / Carbon
Nanofibers / PA-NTC
PA-NTC
EluentACN 90%-H2O 10%/
ACN/ MeOHACN
Eluent volume 0.5-4.0 mL 2.0 mL
Sample volume 5.0-150.0 mL 100.0 mL
Sample flow rate (0.25-0.77) mL min-1 0.67 mL min-1
Eluent flow rate (0.20- 0.67) mL min-1 0.25 mL min-1
Table 2. Optimized parametersFigure 1. FTIR spectrum a) calcium alginate beads (AB)
b) carbon nanotubes (NTC) c) alginate beads / carbon
nanotubes (AB/NTC).
Figure 2. Digital photography
a) AB / NTC wet,
b) AB / NTC dry
(a)
(b)
Figure 3. Scanning electron microscopy (SEM) a) carbon nanotubes (NTC) b) alginate
bead c) interior of alginate bead d) NTC beads e) and f) interior of NTC beads.
(a) (b) (c)
(d) (e) (f )
Currently, we are working in the determination of CF in surface water samples, and
the possible interferents that these samples may contain.
Acknowledgment: ANPCYT, CONICET and SECYT-UNS for the funding
[1] K. Vargas-Berrones, L. Bernal-Jácome, L. Díaz de León-Martínez, R. Flores
Ramírez. Sci. Total Environ., 726 (2020), p. 138493
[2] H.B. Quesada, T.P. de Araújo, D.T. Vareschini, M.A.S.D. de Barros, R.G. Gomes, R.
Bergamasco,Int. J. Biol. Macromol. 164 (2020) 2535–2549.
REFERENCES
INTRODUCTION
REMOVAL OF CAFFEINE FROM WATER SOURCES USING
ALGINATE/CARBON NANOTUBES BEADS
Orduz Angie*, González Natalia, Acebal Carolina, Zanini Graciela.
INQUISUR, Universidad Nacional del Sur (UNS)-CONICET, Bahía Blanca, Buenos Aires, Argentina, 8000
* e-mail: [email protected]
METHODS
AB/NTCs
RESULTS AND DISCUSSION
CONCLUSION
This kind of minicolumns are also useful to extraction system and preconcentration
to improve CF quantification
