Adsorption study of Ibuprofen onto magnetic material based deep eutectic solvents

Nor Munira Hashim¹, Mohd Yusmaidie Aziz¹, Sharlina Mohamad¹, Nur Nadhirah Mohamad Zain¹*¹Integrative Medicine Cluster, Advanced Medical and dental Institute, Universiti Sains Malaysia, 13200 Kepala Batas, Penang, Malaysia

*Corresponding author email address: nurnadhirah@usm.my

DES preparation

Fe3O4 and Fe3O4@DES MNP preparation

This work was funded by the Fundamental Research Grant Scheme, Ministry of Higher Education, Malaysia – 203. CIPPT.6711661 and special thanks to my supervisor, Dr Nur Nadhirah Mohamad Zain for her guiding and my laboratory mates at IPPT, USM

Abstract

Materials and Methods

Summary

Synthesis of DES, Fe3O4 MNP and Fe3O4@DES MNP

Results- Kinetics, Isotherm & Thermodynamics studies

Summary of adsorption study of Ibuprofen

Characterization

• FeCl3 and FeCl2 is added to boiling flask is mol ratio of 2:1 with presence of deionized water• DES was added to synthesis Fe3O4@DES MNP while Fe3O4 was synthesised without presence of DES using a

simple co-precipitation method with slight modification¹.

Conclusion & Future Directions

Acknowledgments

Results – Adsorption study

(1) Silva, V. A. J. et al. (2013) ‘Synthesis and characterization of Fe3O4 nanoparticles coated with fucan polysaccharides’, Journal of Magnetism and Magnetic Materials. Elsevier, 343, pp. 138–143. doi: 10.1016/j.jmmm.2013.04.062(2) Hariani, P. L. et al. (2013) ‘Synthesis and Properties of Fe3O4 Nanoparticles by Co-precipitation Method to Removal Procion Dye’, International Journal of Environmental Science and Development, 4(3), pp. 336–340. doi:

10.7763/ijesd.2013.v4.366(3) Pap, S. et al. (2021) ‘Removal behaviour of NSAIDs from wastewater using a P-functionalised microporous carbon’, Chemosphere. Elsevier Ltd, 264, p. 128439. doi: 10.1016/j.chemosphere.2020.128439(4) Liang, X. X. et al. (2019) ‘Efficient adsorption of diclofenac sodium from aqueous solutions using magnetic amine-functionalized chitosan’, Chemosphere, 217, pp. 270–278. doi: 10.1016/j.chemosphere.2018.11.023.(5) Żółtowska-Aksamitowska, S. et al. (2018) ‘Removal of hazardous non-steroidal anti-inflammatory drugs from aqueous solutions by biosorbent based on chitin and lignin’, Science of the Total Environment, 612, pp. 1223–1233. doi:

10.1016/j.scitotenv.2017.09.037.(6) Khan, A. et al. (2017) ‘Preparation of crosslinked chitosan magnetic membrane for cations sorption from aqueous solution’, Water Science and Technology, 75(9), pp. 2034–2046. doi: 10.2166/wst.2017.078.(7) Li, G., Wang, X. and Row, K. H. (2017) ‘Magnetic Solid-phase Extraction with Fe3O4/Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids for the Rapid Purification of Alkaloid Isomers

(Theobromine and Theophylline) from Green Tea’, Molecules, 22(7), p. 1061. doi: 10.3390/molecules22071061.

Effect of types of adsorbent, pH, contact time, mass of adsorbent, initial concentration and temperature on theadsorption of Ibuprofen

A B

• The MNPs was successfully applied for the adsorptive removal of NSAIDs.• Future studies should involve the application of the materials to adsorb a wider range of

pharmaceuticals

References

The aim of this study to investigate the adsorption study of ibuprofen onto magnetic nanoparticle modified deepeutectic solvent (Fe3O4@DES MNP). The synthesized material was characterized by scanning electron microscopyand Fourier-transform infrared spectroscopy. Batch adsorption experiment was conducted to study the effects ofdifferent adsorption parameters such as solution pH, contact time and mass of adsorbent for both Fe3O4 MNP andFe3O4@DES MNP. Different initial concentrations and temperatures were used to study the equilibrium andthermodynamic of ibuprofen adsorption towards Fe3O4@DES MNP. After optimization, Fe3O4@DES MNP exhibitedadsorption of more than 90% compared to Fe3O4 MNP at only <60 %. The kinetic data were adequately fitted to thepseudo-second-order models for both materials. The result of adsorption isotherm indicated that the adsorptionmechanism models fitted well the Temkin model. The thermodynamic study showed that from the values of ΔHº andΔGº, it was possible to conclude that endothermic and spontaneous reaction occurred during the study. This researchconclude that Fe3O4@DES MNP is a very promising adsorbent for the removal of ibuprofen from the water pollutedby this pharmaceutical drug.

The adsorption of Ibuprofen fitted Pseudo-second-order kinetics model and Temkin isotherm model whileThermodynamics study showed Gibbs free energy change of the adsorption in terms of enthalpy and entropy

+------------

----------------

Hydrogen bond

Hydrogen bond

Heat at 50ºC, 400 rpm

DES

FeCl3 + FeCl2 +deionized water + DES

50ºC, 400 rpm, N2

Δ

90ºC, 400 rpm, N2

Δ

NH4OH

m a s s (m g )

Re

mo

va

l P

erc

en

tag

e (

%)

0 1 0 2 0 3 0 4 0 5 0 6 04 0

6 0

8 0

1 0 0F e 3 O 4 @ D E S M N P

F e 3 O 4 M N P

MNP (y = 0.327x + 0.88, R² = 0.9918)

MNP-DES (y = 0.2061x + 0.1359, R² = 0.9999)

0

5

10

15

20

25

0 10 20 30 40 50 60

t/qt

time(t)

Pseudo-second-orders

MNP MNP DES

Results – Characterization

A

D

Re

mo

va

l P

erc

en

tag

e (

%)

F e 3O4 M

N P

F e 3O4@

D E S MN P

0

2 0

4 0

6 0

8 0

1 0 0

298 K (y = 2.6281x + 4.0197, R² = 0.9157)308 K (y = 2.679x + 6.9288, R² = 0.9403)318 K (y = 1.9175x + 8.0858, R² = 0.9671)328 K (y = 2.5941x + 4.6587, R² = 0.8778)338 K (y = 2.4954x + 4.0574, R² = 0.8832)

0

4

8

12

16

20

-3 -2 -1 0 1 2 3 4

qe

ln Ce

298 K 308 K 318 K 328 K 338 K

FTIR spectra showed spectra: (a) 2-pentanol, (b) decanoic acid, (c) DES (d) Fe3O4 MNP and (e) Fe3O4@DES MNP while SEM images showed (a) Fe3O4 MNP and (b) Fe3O4@DES MNP

B Temkin isotherm model

ΔG° (kJ/mol) ΔH° (kJ/mol) ΔS° (kJ/mol)

298 K 308 K 318 K 328 K 338 K

-80.24 -1140.55 960.5502 -735.908 -899.163 3.161842 11.13494

• The vibration of each functional group of DES and MNPs was identified using Fourier transform-infraredspectroscopy (FT-IR, Thermo Nicolet, Waltham, USA) with the KBr technique in absorption mode at 16 scans.

• SEM analysis showed the changes between the two materials. Images were obtained as platinum coated sampleswere analyzed in a scanning electron microscope (SEM, model QUANTA FEG650, Hillsbro, Oregon, USA)

Adsorption study

• The removal concentration of Ibuprofen was measured using a double beam UV-visible spectrophotometer (PelkinElmer Lambda 25, USA) at absorbance wavelengths 222 nm

Ba

b

c

d

e

A

Discussion

C

• At lower pH, the existing group of MNP is - OH2+. Thus adsorption process is not favourably occur as both MNPs

and Ibuprofen existed in protonated form. At moderate pH around pH3 to pH 5, the highest removal of Ibuprofenwas achieved as the Ibuprofen existed in its neutral form as the pH< pKa (4.91) while MNPs’ group which likelyexisted is –OH caused the adsorption to happen via hydrogen bond. However, the removal percentage dropped atpH 6 as the Ibuprofen became deprotonated and electrostatic repulsion commonly occurred. At pH 7 and above,the prevailing group of MNPs is -O− caused the hydrophobic interaction between negatively charge MNPs anddeprotonated Ibuprofen to occur²¯³.

• There is significant increase of Ibuprofen removal from 5 min to 20 min and no further significant increased until 60min. As the adsorption time increases, the adsorption sites of the adsorbents are gradually occupied whileadsorption rates decreases until adsorption equilibrium is reached4.

• Ibuprofen removal percentage increased significantly from 5 mg to 20 mg and decreased from 30 mg to 60 mg.Same trend had been obtained by when the increase in mass of adsorbent results in an increment contact surfacebetween adsorbent and adsorbate which also increase the number of functional groups that are able to bind toibuprofen6.

• The removal of Ibuprofen was maximum at 10 mg/L at 298 K at decreased afterwards for all temperature tested.However, the adsorption capacity was maximum at the highest initial concentration tested, 60 mg/L at alltemperatures. This showed that the adsorption is endothermic and spontaneous at higher temperature proved bythermodynamics study.

• The adsorption of Ibuprofen also favoured pseudo-second-order kinetics model and Temkin isotherm model. Thisshowed that the adsorption occurred via physisorption and on heterogenous surface with all binding sites on agiven sorbent have uniform energies 6.

• After DES was formed by the mixture of decanoic acid and 2-pentanol, several peaks were observed in the DESspectra, which was due to the O-H stretch, C=O stretch, and C-O stretch. O-H stretch at 3493.6 is due to alcoholgroup of 2-pentanol while C=O stretch and C-O stretch are due to carboxylic group of decanoic acid. Both Fe3O4MNP and Fe3O4@DES MNP have a spectrum at 455.24 due to Fe-O stretch and O-H stretch from 3647.1−3199.0due to hydrogen bonding exists in both nanoparticles. Fe3O4@DES exhibit a spectrum at 1630.7 due to C=Ostretch which may come from DES which proved the successful coating of DES on the MNP.

• Based on SEM images, Fe3O4@DES surface was irregular and agglomeration was observed compared to Fe3O4MNP surface. This may due to the formation of magnetic microsphere surface which not only lessened the mass-transfer resistance but enhanced the surface area of the Fe3O4@DES. This resulted in higher adsorption ofIbuprofen compared to Fe3O4 MNP.

Re

mo

va

l P

erc

en

tag

e (

%)

2 3 4 5 6 7 8 9 1 00

2 0

4 0

6 0

8 0

1 0 0 F e 3 O 4 M N PF e 3 O 4 @ D E S M N P

p H

T im e (m in )

Re

mo

va

l P

erc

en

tag

e (

%)

0 1 0 2 0 3 0 4 0 5 0 6 04 0

6 0

8 0

1 0 0F e 3 O 4 M N P

F e 3 O 4 @ D E S M N PC

Re

mo

va

l P

erc

en

tag

e (

%)

0 1 0 2 0 3 0 4 0 5 0 6 04 0

6 0

8 0

1 0 02 9 8 K

3 0 8 K

3 1 8 K

3 2 8 K

In itia l c o n c e n tra tio n (m g /L )

3 3 8 K

In it ia l c o n c e n tra t io n (m g /L )

qe

(mg

/g)

0 2 0 4 0 6 00

5

1 0

1 5

2 0

2 5 2 9 8 K

3 0 8 K

3 1 8 K

3 2 8 K

3 3 8 K

Decanoic acid 2-pentanol

b

a