synthesisofatenolol-imprintedpolymerswithmethyl...

Research ArticleSynthesis of Atenolol-Imprinted Polymers with MethylMethacrylate as FunctionalMonomer in Propanol Using Bulk andPrecipitation Polymerization Method

Aliya Nur Hasanah Traju Ningtias Dwi Utari and Rimadani Pratiwi

Department of Pharmaceutical Analysis and Medicinal Chemistry Faculty of Pharmacy Padjadjaran UniversityJl Raya Bandung Sumedang KM 215 Jatinangor Sumedang Indonesia

Correspondence should be addressed to Aliya Nur Hasanah aliyanhasanahunpadacid

Received 11 February 2019 Accepted 24 March 2019 Published 19 May 2019

Academic Editor Nuria Fontanals

Copyright copy 2019 Aliya Nur Hasanah et al is is an open access article distributed under the Creative Commons AttributionLicense which permits unrestricted use distribution and reproduction in any medium provided the original work isproperly cited

Atenolol is one of the beta-1 blocker drugs that is misused by athletes to increase their performance during competitionerefore it is important to analyze atenolol levels in blood selectively e preparation method that can be used in separatingatenolol in sample is molecular imprinting solid-phase extraction (MI-SPE) because it has good selectivity and sensitivity isstudy aims to examine the characteristics and analytical performance of imprinted polymers synthesized from functionalmonomer methyl methacrylate e stages of this study include the determination of association constants synthesis of sorbentMI-SPE atenolol using the bulk polymerization method and precipitation with atenolol as the template methyl methacrylate asthe functional monomer and propanol as the porogen e template was extracted from a polymer and then the adsorptionability capacity and selectivity of MI-SPE and finally the application of the best MI-SPE to spiked serum samples were de-termined MI-SPE was also characterized by using Fourier-transform instrument infrared (FTIR) and scanning electron mi-croscope (SEM) e result of characterization with FTIR and SEM showed that MIP made by the precipitation polymerizationmethod was completely polymerized more porous and produced smaller particle size with an average value of 0274 μm It hadbetter analytic performances than MIP made by bulk polymerization with affinity value 03607mgg and homogeneity value13246 and good selectivity toward atenolol with imprinting factor value 22519 Application of MI-SPE to spiked serum sampleshas an excellent recovery percentage of 9546 over 0 for the nonimprinting one Based on the result of study MIP made byprecipitation polymerization could be used to extract atenolol on serum samples toward drug analysis

1 Introduction

Atenolol is an adrenoreceptor inhibitor that is selective toβ-1 and it is used to treat hypertension cardiac arrhythmiasangina pectoris myocardial infarction and other cardio-vascular disorders [1] Atenolol is often misused by athletesto improve their performance because it reduces heart rateand tremors us the use of atenolol is prohibited by theWorld AntiDoping Agency (WADA) and categorized asdoping drugs erefore monitoring levels of atenolol inblood is very important A selective extraction method isneeded because atenolol is in a complicated sample matrix[2]e preparationmethod that is currently developing and

has good selectivity is molecularly imprinted solid-phaseextraction (MI-SPE) Molecular-imprinting is a techniquefor preparing polymeric materials that have prearrangedstructures and specific molecular recognition ability [3]

In this case the selection of functional monomer andporogen has important role in producing molecular-specificcavities of templates Methyl methacrylate is a functionalmonomer that can act as a hydrogen bond acceptor to itstemplate [4] Other researchers have done research on MI-SPE for atenolol [5ndash7] but none of them used precipitationpolymerization as we used in this study and the recoveriesare below 80e porogen chosen in this study is propanolbecause it has low polarity that can reduce interference

HindawiJournal of Analytical Methods in ChemistryVolume 2019 Article ID 9853620 7 pageshttpsdoiorg10115520199853620

during the polymerization process and increase the numberof MIP-binding sites [8]

In this study we describe the synthesis of MIP for ex-traction of atenolol and for use as SPE sorbents for theselective extraction of atenolol in blood samples using twodifferent methods e methods are precipitation and bulkpolymerization e polymer was synthesized and charac-terized for the ability of the polymer to bind with atenololselectively e MIP was synthesized using methyl meth-acrylate as a functional monomer ethylene glycol dime-thacrylate as a cross linker propanol as a porogenic solventand benzoyl peroxide as an initiator e binding affinity ofthe binding sites in the polymer was assessed using theadsorption test e characterization was carried out using aFourier-transform infrared (FTIR) spectroscope and scan-ning electron microscope (SEM) At the end this polymerwas then used as an extraction material of atenolol from thespiked blood serum

2 Materials and Methods

21 Materials Acetonitrile was purchased from FisherChemical atenolol metoprolol and propranolol werepurchased from TCI Acetic acid 96 benzoyl peroxide(BPO) methanol potassium bromide and propanol werepurchased from Merck Ethylene glycol dimethacrylate(EGDMA) and methyl methacrylate (MMA) were pur-chased from Sigma-Aldrich All chemicals used werecommercially available and were of analytical gradeMethanol used was of HPLC gradient grade Methylmethacrylate was purified before being used with aluminiumchloride

22 Determination of Association Constant of MonomerTemplate Atenolol 2times10minus5M was diluted in propanol25ml of the solution was measured using a UV-Vis spec-trophotometer Methyl methacrylate solution of 001M wasadded gradually from 10 μl 20 μl 30 μl 40 μl 50 μl 100 μland so on until there was no significant increase in theabsorbance valuee results are plotted on a graph between1[G] and 1ΔY e constant association was calculatedusing BenesindashHildebrand equation [9]

1ΔY

1

YΔHGKa[G]+

1YΔHG

(1)

where ΔY is the change in absorbance YΔHG is the changein absorbance at the end of titration and [G] is the con-centration added [10]

23 Synthesis of Atenolol-Imprinted Polymer Using BulkPolymerization A prepolymerization solution consisting of0263 g atenolol 400 μl MMA 377ml EGDMA 250mgBPO and 5ml propanol was prepared in a vial e reactionmolar ratio of the template functional monomer and crosslinker for the preparation of MIP was 1 4 20 e solutionwas sonicated for 20minutes to remove oxygen eatenolol-MIP was placed in an oven at 70degC for 1 hour andmoved to water bath and kept at 70degC for 18 hours for

polymerization e resulting bulk polymers were groundand sieved usingmesh 60 washed using 20mlmethanol anddried at 50degC e nonimprinted polymer (NIP) was pre-pared simultaneously under the same condition without theaddition of the template [8ndash11]

24 Synthesis of Atenolol-Imprinted Polymer Using Pre-cipitation Polymerization A prepolymerization solutionconsisting of 0133 g atenolol 200 μl MMA 1885mlEGDMA 750mg BPO and 175ml propanol was prepared ina glass vial e reaction molar ratio of the templatefunctional monomer and cross linker for the preparation ofMIP was 1 4 20 e solution was sonicated for 20minutesto remove oxygen e atenolol-MIP was placed in an ovenat 70degC for 1 hour and moved to water bath shaker and keptat 70degC for 18 hours for polymerization e resulting bulkpolymers were washed using 40ml methanol and dried at50degC e nonimprinted polymer (NIP) was prepared si-multaneously under the same condition without the addi-tion of template [9]

25 Extraction of Template e Soxhlet apparatus was usedfor template removal from the synthesized MIP usingmethanol and acetic acid (9 1) for 24 hours en thepolymers were washed using 20ml methanol and water anddried at 50degC for 18 hours

MIP was monitored using 20mg MIP diluted in 5mlmethanol triplicate en MIP was sonicated for 5minutesand set aside for 24 hourse extraction process is completewhen the liquid leaching results in MIP no longer containthe template when monitored using a UV-Vis spectro-photometer [11]

26 EvaluationofBindingAbility Twenty milligrams of MIPin vial was incorporated into 5ml atenolol at a concentrationof 5 ppm in various solutions such as methanol acetonitrileand methanol acetonitrile (1 1) triplicate e vials wereshaken using a shaker at 120 rpm for 3 hours at roomtemperature to reach equilibrium and then filtered efiltrate was measured by using a UV-Vis spectrophotometere evaluation of NIP was carried out by the same procedureas that for MIP [11]

27 Evaluation of Binding Capacity Five milliliters of se-lected solvent from evaluation 26 containing 25 5 7510 ppm of atenolol was added to 20mg of MIP in vialstriplicate e vials were shaken using a shaker at 120 rpmfor 3 hours at room temperature and then filtered e fil-trate was measured by using a UV-Vis spectrophotometere results are plotted for isotherm Freundlich adsorptioncurve e adsorption curve of NIP was plotted by the sameprocedure as that for MIP [11 12]

28 Determination of Selectivity Atenolol metoprolol andpropranolol were used to determine the relative selectivity ofMIP 5ml of selected solvent from evaluation 26 containing

2 Journal of Analytical Methods in Chemistry

5 ppm of atenolol metoprolol propranolol was added to20mg of MIP in vials triplicate e vials were shaken usinga shaker at 120 rpm for 3 hours at room temperature andthen filtered e filtrate was measured by using a UV-Visspectrophotometer e evaluation of NIP was carried outby the same procedure as that forMIPe imprinting factorwas calculated using the following equation

KD Ci minusCf( 1113857V

Cfm

IF KD MIPKD NIP

(2)

where KD is the distribution coefficient Ci and Cf are theconcentration of atenolol before and after the adsorptionexperiments respectively V is the volume of solutioncontaining atenolol and W is the weight of the polymer[13 14]

29 Application of the Polymer in Serum Samples e bloodserum is obtained by centrifugation of blood at a speed of5000 rpm for 5minutes then the supernatant is collectede blood serum is spiked with 2 ppm atenolol in water espiked serum is passed into MIP-SPE and NIP-SPEe SPEsystem is conditioned with methanol acetonitrile (1 1)3times1mL washing solvents using acetonitrile and elutionusing methanol trifluoroacetic acid 005 (99 1) 3times1mLe elution results were then analyzed by HPLC using themobile phase of methanol water + triethylamine 005which was adjusted to pH 3 with phosphoric acid (15 85)

210 Characterization of Atenolol-Imprinted Polymer echemical structure of MIP and NIP samples was charac-terized by FTIR spectroscopy (IRPrestige-21 Shimadzu)Samples were ground and pressed into KBr plates eanalysis was performed between 400 and 4000 cmminus1 esurface morphology was analyzed by SEM [11 15 16]

3 Results and Discussion

31 Determination of Association Constant of MonomerTemplate Before the polymerization step the associationconstant was determined to know the ability of MMAfunctional monomer to bind with atenolol to form a stablecomplex in prepolymerization solution with the titrationmethod using a UV-Vis spectrophotometer [17]

e association constant was 199625Mminus1 calculated byBenesindashHildebrand equation (Figure 1)e higher the valueof the association constant the more stable the complex thatoccurs during polymerization and the better the imprintingeffect [18 19]

32 Synthesis of Atenolol-Imprinted Polymer Using Bulk andPrecipitation Polymerization e purpose of the synthesisby two methods is to see the effectiveness of each polymerproduced In molecular-imprinting processes the selectionof the functional monomer is an important factor that affects

the binding affinity and specificity of the imprinted polymere formulations were prepared by the bulk and pre-cipitation polymerization method using MMA as themonomer BPO as the initiator and EGDMA as the crosslinker e ratio of the monomer affected the particle sizesand yields of the obtained MIP and NIP [20]

33 Extraction of Template e purpose of extraction was toremove atenolol groups that bind to polymers and to formcavities that were complementary to atenolol [18] Atenololis soluble in methanol so it was used to extract the templateAcetic acid was added to disrupt the hydrogen bond betweenatenolol and the functional monomer MMA to facilitate theremoval of atenolol [12 21]

34 Evaluation of Binding Ability In order to know thebinding ability and to find out the optimum conditions forthe template to be recognized by the MIP that is beingprepared a standard solution of atenolol of 5 ppm wasinitially prepared in various solvents such as methanolacetonitrile and methanol acetonitrile (1 1) e filtratethat indicated the amount of unbound analyte was mea-sured e atenolol-binding ability of MIPs was investigatedand compared with that of NIPs [15]

From Figure 2 it is known that theMIP synthesized usingthe bulk polymerization method can bind with atenolol inacetonitrile with 31854 of binding However NIPs in othersolvents such as methanol and methanol acetonitrile (1 1)showed a higher percent of binding 89908 and 39483respectively is suggests that NIPs swelled better in thesesolvents From Figure 3 the MIP synthesized using theprecipitation polymerization method can bind atenolol inmethanol acetonitrile (1 1) with 38543 of binding isshowed that acetonitrile has the ability to lead atenololproperly to the binding site in MIP [13 22 23]

35 Evaluation of Binding Capacity is evaluation is usedto study the affinity between MIP and analyte target [23]e relationship between the amount of analyte bound to theadsorbent (B) and the amount of free analyte (F) is illus-trated in the following Freundlich isotherm equation

y = 00008x + 01597R2 = 09992

0 2000 4000 6000 8000 10000 12000 140000

2

4

6

8

10

12

1[MMA] Mndash1

1∆

abso

rban

ce

Figure 1 Relationship between 1(methyl methacrylate) to 1Δabsorbance

Journal of Analytical Methods in Chemistry 3

logB m logF + log a (3)

e value of m indicates the homogeneity index when itapproaches 1 the sorbent is more homogeneous and when itapproaches 0 the sorbent is more heterogeneous [13] evalue of a indicates sorbent affinity the higher the affinityobtained the more the capacity of the sorbent to bind to theanalyte target [24 25] Table 1 shows the binding capacityvalue of each MIP and NIP e MIP that was synthesizedusing the precipitation method has a homogeneity value closeto 1 which is 13426 and an affinity value of 03607 It hasbetter a and m values than the MIP that was synthesized bybulk polymerization which indicates better imprinting effect

36 Determination of Selectivity e selectivity for atenololof MIP was investigated by determining its binding abilitycompared with other β-blocker drugs such as metoprololand propranolol A testing solution containing 5 ppm ofeach drug (atenolol metoprolol and propranolol) wasprepared [17] MIP and NIP were prepared 20mg in eachvial Solution and MIP were combined in a vial then shakenusing a shaker to reach equilibrium e filtrate was mea-sured using a UV-Vis spectrophotometer e distributioncoefficient (CD) and imprinting factor (IF) were calculatede results (Tables 2 and 3) showed that atenolol can bind

with MIP synthesized by the precipitation method with adistribution coefficient of 156864mlg which is higher thanthat of NIP which was 6966mlg e imprinting factor ofMIP was 22519 is indicates that the MIP that wassynthesized by the precipitation method had a higher se-lectivity for atenolol than the other β-blocker drugs us itwas selective for atenolol

37 Application of the Polymer in Serum Samples epolymer made by precipitation polymerization has betteranalytical performances compared to bulk Based on thisresult a 100mg polymer made by precipitation polymeri-zation then was packed into cartridges and used as an SPEmaterial over the spiked blood serum e imprintingpolymer gain recovery percentage was 9546plusmn 344compared to nonimprinted 000plusmn 000 is resultshowed an excellent imprinting effect and was linear to theselectivity result which had an imprinting factor value of22519 compared with NIP All experiments were done usingthe same cartridges (over 20 cycles) and the results are stillin the acceptance range (SD below 5) e result of thispolymer is better than that of the one in the previous study[7] and fits with criteria recoveries of analyte from biologicalfluid Table 4

38 Characterization of Atenolol-Imprinted Polymer eFTIR spectrums of the MIP by bulk and precipitation po-lymerization are presented in Figures 4 and 5 e completepolymerization process was characterized when the doubletpeak (vinyl group H2CCH-) was absent at the

9238 11309

38543

0073

10620

2613

00005000

10000150002000025000300003500040000450005000055000

Acetonitrile Methanol Methanol Acetonitrile(1 1)

MIPNIP

Figure 3 Binding ability MMA propanol polymer precipitationmethod (n 3)

3185424505

18678342

89908

39483

0000

20000

40000

60000

80000

100000

120000


MIPNIP

Figure 2 Binding ability MMA propanol polymer bulk method(n 3)

Table 1 Binding capacity MMA propanol bulk and precipitationmethod (n 3)

ValueMMA propanol bulk MMA propanol

precipitationMIP NIP MIP NIP

M minus01909 0102 13246 23672a (mgg) 007 00872 03607 00028R2 00198 00182 09547 08061

Table 2 Selectivity of MMA propanol polymer by bulk poly-merization (n 3)

Analyte Atenolol Propranolol Metoprolol

KD (mlg) MIP 115385 218624 0170NIP 22135 332559 0022

Imprinting factor 5213 0657 7869

Table 3 Selectivity of MMA propanol polymer by precipitationpolymerization (n 3)


KD (mlg) MIP 156863 9732 334172NIP 6966 176443 144475



Table 4 Result of application of the polymer in serum samples compared to previous study [7]

PolymerMMAmade by precipitation polymerization Polymer from previous study [7]Imprinting factor (IF) 22519 418Recoveries 9546 745ndash753

T

150

135

120

105

90

75

60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP ruah

MIP ruah 1MIP ruah selelah 1

MIP ruah sebelum 1Atenolol 1

No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)a

b

c

d

Figure 4 FTIR spectrum (a) atenolol (b) MIP by bulk before extraction (c) MIP by bulk after extraction (d) NIP by bulk

T

120

105

90

75

a

b

cd60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP pengendapan

MIP pengendapan 1MIP pengendapan selelah 1

MIP pengendapan sebelum 1Atenolol 1

No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)

Figure 5 FTIR spectrum (a) atenolol (b) MIP by precipitation after extraction (c) NIP by precipitation (d) MIP by precipitation beforeextraction


wavenumber 1600 cmminus1 1660 ndash1635 cmminus1 990plusmn 5 cmminus1and 910plusmn 5 cmminus1 [26]

e morphologies and particle size of MIP and NIP thatwere synthesized by precipitation polymerization were de-termined using SEM and the results are shown in Figure 6e SEM images of the NIP revealed a spherical and smoothsurface without evidence of collapsed particles whereasthose of the MIP revealed spheres with small pores on thesurface [17] MIP had smaller particles it suggested that thetemplate compound has an important influence on theparticle growth during the precipitation polymerization[20]

4 Conclusions

e molecularly imprinted polymer of atenolol with MMAas the functional monomer in propanol using the pre-cipitation polymerization synthesis method had better an-alytic performances thanMIP that was synthesized using thebulk polymerization method e value of affinity was03607mgg and the value of homogeneity was 13246selective toward atenolol with an imprinting factor of 22519Application of MI-SPE to spiked serum samples has anexcellent recovery percentage of 9546 over 0 for thenonimprinting one e results of characterization alsoshowed that the MIP that was synthesized using the pre-cipitation method had small-sized homogenic particles

Data Availability

e data used to support the findings of this study are in-cluded within the article

Conflicts of Interest

e authors declare that there are no conflicts of interestregarding the publication of this paper

Acknowledgments

Funding from the Ministry of Research Technology andHigher Education Republic of Indonesia through PenelitianTerapan Unggulan Perguruan Tinggi (PTUPT) 2018 throughGrant no 381cUN6OLT2018 is greatly acknowledged

References

[1] P Gupta and R N Goyal ldquoAmino functionalized grapheneoxide and polymer nanocomposite based electrochemicalplatform for sensitive assay of anti-doping drug atenolol inbiological fluidsrdquo Journal of the Electrochemical Societyvol 163 no 13 pp B601ndashB608 2016

[2] A Beltran F Borrull R M Marce and P A G CormackldquoMolecularly imprinted polymers useful sorbents for selectiveextractionsrdquo TrACmdashTrends in Analytical Chemistry vol 29no 11 pp 1363ndash1375 2010

[3] H A Panahi E Moniri M Aliasghari and L HajaghababaiildquoSelective sorption and determination of atenolol in phar-maceutical and biological samples by molecular imprintingusing new copolymer beads as functional matricrdquo Journal ofLiquid Chromatography amp Related Technologies vol 38 no 2pp 222ndash228 2014

[4] K Golker B Karlsson A Rosengren and I Nicholls ldquoAfunctional monomer is not enough principal componentanalysis of the influence of template complexation in pre-polymerization mixtures on imprinted polymer recognitionandmorphologyrdquo International Journal of Molecular Sciencesvol 15 no 11 pp 20572ndash20584 2014

[5] A E Bodoki B-C Iacob L E Gliga et al ldquoImprovedenantioselectivity for atenolol employing pivot based mo-lecular imprintingrdquo Molecules vol 23 no 8 p 1875 2018

[6] T Alizadeh ldquoSynthesis of a nano-sized chiral imprintedpolymer and its use as an (S)-atenolol carrier in the bulk liquidmembranerdquo Journal of Separation Science vol 37 no 14pp 1887ndash1895 2014

[7] Y Gorbani H Yılmaz and H Basan ldquoSpectrofluorimetricdetermination of atenolol from human urine using high-affinity molecularly imprinted solid-phase extraction sor-bentrdquo Luminescence vol 32 no 8 pp 1391ndash1397 2017

[8] H Yan and K Row ldquoCharacteristic and synthetic approach ofmolecularly imprinted polymerrdquo International Journal ofMolecular Sciences vol 7 no 5 pp 155ndash178 2006

[9] S Song A Wu X Shi R Li Z Lin and D Zhang ldquoDe-velopment and application of molecularly imprinted poly-mers as solid-phase sorbents for erythromycin extractionrdquoAnalytical and Bioanalytical Chemistry vol 390 no 8pp 2141ndash2150 2008

[10] P ordarson ldquoDetermining association constants from ti-tration experiments in supramolecular chemistryrdquo ChemicalSociety Reviews vol 40 no 3 pp 1305ndash1323 2011

[11] A N Hasanah R E Kartasasmi and S Ibrahim ldquoSynthesisand application of glibenclamide imprinted polymer for solid

(a) (b)

Figure 6 SEM images of (a) MIP by precipitation polymerization and (b) NIP by precipitation polymerization


phase extraction in serum samples using itaconic acid asfunctional monomerrdquo Journal of Applied Sciences vol 15no 11 pp 1288ndash1296 2015

[12] S Ansari and A Ghorbani ldquoMolecularly imprinted polymers(MIP) for selective solid phase extraction of celecoxib in urinesampeles followed by high performance liquid chromatog-raphyrdquo Journal of Chemical Health Risks vol 7 2017

[13] R J Ansell ldquoCharacterization of the binding properties ofmolecularly imprinted polymersrdquo Advances in BiochemicalEngineering Biotechnology vol 10 no 7 2015

[14] P Liu L Liu L Zhang N Jiang Z Liu and Y WangldquoSynthesis and characterization of molecularly imprintedpolymers for recognition of ciprofloxacinrdquo Frontiers ofChemistry in China vol 3 no 4 pp 378ndash383 2008

[15] A N Hasanah et al ldquoStudy of the binding ability of molecularimprinted solid phase extraction for glibenclamide by opti-mizing template monomer crosslinker ratiordquo InternationalJournal of Chemical Science vol 12 no 3 pp 1288ndash12962014

[16] J N T Nguyen and A M Harbison ldquoScanning Electronmicroscopy sample preparation and imagingrdquo Methods inMolecular Biology vol 1606 pp 71ndash84 2017

[17] S Scorrano L Mergola R Del Sole and G VasapolloldquoSynthesis of molecularly imprinted polymers for amino acidderivates by using different functional monomersrdquo In-ternational Journal of Molecular Sciences vol 12 no 3pp 1735ndash1743 2011

[18] S N N S Hashim R I Boysen L J Schwarz B Danylec andM T W Hearn ldquoA comparison of covalent and non-covalentimprinting strategies for the synthesis of stigmasterolimprinted polymersrdquo Journal of Chromatography A vol 1359pp 35ndash43 2014

[19] K Lim and C Holdsworth ldquoEffect of formulation on thebinding efficiency and selectivity of precipitation molecularlyimprinted polymersrdquoMolecules vol 23 no 11 p 2996 2018

[20] P Tonglairoum W Chaijaroenluk T RojanarataT Ngawhirunpat P Akkaramongkolporn and P OpanasopitldquoDevelopment and characterization of propranolol selectivemolecular imprinted polymer composite electrospun nanofibermembranerdquo AAPS PharmSciTech vol 14 no 2 pp 838ndash8462013

[21] L Chen ldquoMolecular imprinting perspectives and applica-tionsrdquo Royal Society of Chemistry Advances Review Articlevol 45 no 8 pp 1ndash75 2016

[22] F Omidi M Behbahani S Samadi A Sedighi andS J Shahtaheri ldquoCoupling of molecular imprinted polymernanoparticles by high performance liquid chromatography asan efficient technique for sensitive and selective trace de-termination of 4-chloro-2-methylphenoxy acetic acid incomplex matricesrdquo Iranian Journal of Public Health vol 43no 5 pp 645ndash657 2014

[23] C Alvarez-Lorenzo and A Concheiro Handbook of Molec-ularly Imprinted Polymers Smithers Rapra Technology LtdShawbury UK 2013

[24] G T Rushton C L Karns and K D Shimizu ldquoA criticalexamination of the use of the Freundlich isotherm in char-acterizing molecularly imprinted polymers (MIPs)rdquo Analy-tica Chimica Acta vol 528 no 1 pp 107ndash113 2005

[25] W Cai and R B Gupta ldquoMolecularly-imprinted polymersselective for tetracycline bindingrdquo Separation and PurificationTechnology vol 35 no 3 pp 215ndash221 2004

[26] B C Smith Infrared Spectral Interpretation A SystematicApproach CRC Press LLC Boca Raton FL USA 1999


TribologyAdvances in

Hindawiwwwhindawicom Volume 2018


International Journal ofInternational Journal ofPhotoenergy


Journal of

Chemistry


Advances inPhysical Chemistry

Hindawiwwwhindawicom

Analytical Methods in Chemistry

Journal of

Volume 2018

Bioinorganic Chemistry and ApplicationsHindawiwwwhindawicom Volume 2018

SpectroscopyInternational Journal of


Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom

The Scientific World Journal

Volume 2018

Medicinal ChemistryInternational Journal of


NanotechnologyHindawiwwwhindawicom Volume 2018

Journal of

Applied ChemistryJournal of



Biochemistry Research International


Enzyme Research


Journal of

SpectroscopyAnalytical ChemistryInternational Journal of


MaterialsJournal of



BioMed Research International Electrochemistry

International Journal of


Na

nom

ate

ria

ls


Journal ofNanomaterials

Submit your manuscripts atwwwhindawicom

during the polymerization process and increase the numberof MIP-binding sites [8]

In this study we describe the synthesis of MIP for ex-traction of atenolol and for use as SPE sorbents for theselective extraction of atenolol in blood samples using twodifferent methods e methods are precipitation and bulkpolymerization e polymer was synthesized and charac-terized for the ability of the polymer to bind with atenololselectively e MIP was synthesized using methyl meth-acrylate as a functional monomer ethylene glycol dime-thacrylate as a cross linker propanol as a porogenic solventand benzoyl peroxide as an initiator e binding affinity ofthe binding sites in the polymer was assessed using theadsorption test e characterization was carried out using aFourier-transform infrared (FTIR) spectroscope and scan-ning electron microscope (SEM) At the end this polymerwas then used as an extraction material of atenolol from thespiked blood serum

2 Materials and Methods

21 Materials Acetonitrile was purchased from FisherChemical atenolol metoprolol and propranolol werepurchased from TCI Acetic acid 96 benzoyl peroxide(BPO) methanol potassium bromide and propanol werepurchased from Merck Ethylene glycol dimethacrylate(EGDMA) and methyl methacrylate (MMA) were pur-chased from Sigma-Aldrich All chemicals used werecommercially available and were of analytical gradeMethanol used was of HPLC gradient grade Methylmethacrylate was purified before being used with aluminiumchloride

22 Determination of Association Constant of MonomerTemplate Atenolol 2times10minus5M was diluted in propanol25ml of the solution was measured using a UV-Vis spec-trophotometer Methyl methacrylate solution of 001M wasadded gradually from 10 μl 20 μl 30 μl 40 μl 50 μl 100 μland so on until there was no significant increase in theabsorbance valuee results are plotted on a graph between1[G] and 1ΔY e constant association was calculatedusing BenesindashHildebrand equation [9]

1ΔY

1

YΔHGKa[G]+

1YΔHG

(1)

where ΔY is the change in absorbance YΔHG is the changein absorbance at the end of titration and [G] is the con-centration added [10]

23 Synthesis of Atenolol-Imprinted Polymer Using BulkPolymerization A prepolymerization solution consisting of0263 g atenolol 400 μl MMA 377ml EGDMA 250mgBPO and 5ml propanol was prepared in a vial e reactionmolar ratio of the template functional monomer and crosslinker for the preparation of MIP was 1 4 20 e solutionwas sonicated for 20minutes to remove oxygen eatenolol-MIP was placed in an oven at 70degC for 1 hour andmoved to water bath and kept at 70degC for 18 hours for

polymerization e resulting bulk polymers were groundand sieved usingmesh 60 washed using 20mlmethanol anddried at 50degC e nonimprinted polymer (NIP) was pre-pared simultaneously under the same condition without theaddition of the template [8ndash11]

24 Synthesis of Atenolol-Imprinted Polymer Using Pre-cipitation Polymerization A prepolymerization solutionconsisting of 0133 g atenolol 200 μl MMA 1885mlEGDMA 750mg BPO and 175ml propanol was prepared ina glass vial e reaction molar ratio of the templatefunctional monomer and cross linker for the preparation ofMIP was 1 4 20 e solution was sonicated for 20minutesto remove oxygen e atenolol-MIP was placed in an ovenat 70degC for 1 hour and moved to water bath shaker and keptat 70degC for 18 hours for polymerization e resulting bulkpolymers were washed using 40ml methanol and dried at50degC e nonimprinted polymer (NIP) was prepared si-multaneously under the same condition without the addi-tion of template [9]

25 Extraction of Template e Soxhlet apparatus was usedfor template removal from the synthesized MIP usingmethanol and acetic acid (9 1) for 24 hours en thepolymers were washed using 20ml methanol and water anddried at 50degC for 18 hours

MIP was monitored using 20mg MIP diluted in 5mlmethanol triplicate en MIP was sonicated for 5minutesand set aside for 24 hourse extraction process is completewhen the liquid leaching results in MIP no longer containthe template when monitored using a UV-Vis spectro-photometer [11]

26 EvaluationofBindingAbility Twenty milligrams of MIPin vial was incorporated into 5ml atenolol at a concentrationof 5 ppm in various solutions such as methanol acetonitrileand methanol acetonitrile (1 1) triplicate e vials wereshaken using a shaker at 120 rpm for 3 hours at roomtemperature to reach equilibrium and then filtered efiltrate was measured by using a UV-Vis spectrophotometere evaluation of NIP was carried out by the same procedureas that for MIP [11]

27 Evaluation of Binding Capacity Five milliliters of se-lected solvent from evaluation 26 containing 25 5 7510 ppm of atenolol was added to 20mg of MIP in vialstriplicate e vials were shaken using a shaker at 120 rpmfor 3 hours at room temperature and then filtered e fil-trate was measured by using a UV-Vis spectrophotometere results are plotted for isotherm Freundlich adsorptioncurve e adsorption curve of NIP was plotted by the sameprocedure as that for MIP [11 12]

28 Determination of Selectivity Atenolol metoprolol andpropranolol were used to determine the relative selectivity ofMIP 5ml of selected solvent from evaluation 26 containing




Cfm

IF KD MIPKD NIP

(2)













y = 00008x + 01597R2 = 09992

0 2000 4000 6000 8000 10000 12000 140000

2

4

6

8

10

12

1[MMA] Mndash1

1∆

abso

rban

ce









9238 11309

38543

0073

10620

2613

00005000

10000150002000025000300003500040000450005000055000


MIPNIP


3185424505

18678342

89908

39483

0000

20000

40000

60000

80000

100000

120000


MIPNIP





M minus01909 0102 13246 23672a (mgg) 007 00872 03607 00028R2 00198 00182 09547 08061



KD (mlg) MIP 115385 218624 0170NIP 22135 332559 0022




KD (mlg) MIP 156863 9732 334172NIP 6966 176443 144475





T

150

135

120

105

90

75

60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP ruah



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)a

b

c

d


T

120

105

90

75

a

b

cd60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP pengendapan



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)





4 Conclusions


Data Availability




Acknowledgments


References












(a) (b)

























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls






Cfm

IF KD MIPKD NIP

(2)













y = 00008x + 01597R2 = 09992

0 2000 4000 6000 8000 10000 12000 140000

2

4

6

8

10

12

1[MMA] Mndash1

1∆

abso

rban

ce









9238 11309

38543

0073

10620

2613

00005000

10000150002000025000300003500040000450005000055000


MIPNIP


3185424505

18678342

89908

39483

0000

20000

40000

60000

80000

100000

120000


MIPNIP





M minus01909 0102 13246 23672a (mgg) 007 00872 03607 00028R2 00198 00182 09547 08061



KD (mlg) MIP 115385 218624 0170NIP 22135 332559 0022




KD (mlg) MIP 156863 9732 334172NIP 6966 176443 144475





T

150

135

120

105

90

75

60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP ruah



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)a

b

c

d


T

120

105

90

75

a

b

cd60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP pengendapan



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)





4 Conclusions


Data Availability




Acknowledgments


References












(a) (b)

























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls










9238 11309

38543

0073

10620

2613

00005000

10000150002000025000300003500040000450005000055000


MIPNIP


3185424505

18678342

89908

39483

0000

20000

40000

60000

80000

100000

120000


MIPNIP





M minus01909 0102 13246 23672a (mgg) 007 00872 03607 00028R2 00198 00182 09547 08061



KD (mlg) MIP 115385 218624 0170NIP 22135 332559 0022




KD (mlg) MIP 156863 9732 334172NIP 6966 176443 144475





T

150

135

120

105

90

75

60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP ruah



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)a

b

c

d


T

120

105

90

75

a

b

cd60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP pengendapan



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)





4 Conclusions


Data Availability




Acknowledgments


References












(a) (b)

























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls






T

150

135

120

105

90

75

60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP ruah



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)a

b

c

d


T

120

105

90

75

a

b

cd60

45

30

15

4000 30003500 2500 2000 1750 1500 1250 1000 750 500

0

1cmNIP pengendapan



No doubletpeak

(vinyl group)

No doubletpeak

(vinyl group)





4 Conclusions


Data Availability




Acknowledgments


References












(a) (b)

























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls






4 Conclusions


Data Availability




Acknowledgments


References












(a) (b)

























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls


























Journal of

Chemistry





Journal of

Volume 2018






Volume 2018




Journal of






Enzyme Research


Journal of



MaterialsJournal of






Na

nom

ate

ria

ls




synthesisofatenolol-imprintedpolymerswithmethyl...

Documents