Research Article
Journal of
Analytical & Bioanalytical Techniques
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ISSN: 2155-9872
Khansari et al., J Anal Bioanal Tech 2017, 8:2
DOI: 10.4172/2155-9872.1000351
Volume 8 • Issue 2 • 1000351
J Anal Bioanal Tech, an open access journal
ISSN: 2155-9872
Keywords: Molecularly imprinted polymer; Methylphenidate;
Pharmaceutical analysis; Solid-phase extraction; Afnity assay;
Template polymerization
Introduction
Recently, there have been an increasing interest in potential
applications of highly selective molecularly imprinted polymers,
MIPs. Especially their applications in analysis of drugs and other
compounds in biological and environmental samples. Applicability
of Imprinted polymers [1-4] are in various analytical techniques,
including liquid chromatography [3,5], capillary electrophoresis,
capillary electrochromatography [6], solid-phase extraction [7], and
‘immunoassay’ [8], have been investigated. An inhere advantage of
molecular imprinting, which has extensively been testifed by many
examples above, is the possibility to synthesize sorbents with selectivity
pre-determined for a particular analyte. Te fundamental step in this
technique is polymerization of functional and cross-linking monomers
in the presence of a templating ligand, or imprint species. Subsequent
removal of the imprint molecules leaves behind ‘memory sites’, or
imprints, in a solid, highly cross-linked polymer network. Te general
belief holds that the functional monomers are spatially fxed in the
polymer via their interaction with the imprint species during the
polymerization reaction.
Attention defcit hyperactivity disorder (ADHD) is a common
neurobehavioral disorder in childhood, which is estimated to strike up
to 10% of the general population [9,10]. Methylphenidate (MPH) is a
psychostimulant drug approved primarily for the treatment of attention
defcit hyperactivity disorder (ADHD) and narcolepsy [11]. Tis drug
fts to the piperidine class of compounds and increases the levels of
dopamine and noradrenaline in the brain through reuptake inhibition
of the monoamine transporters [11]. Te main urinary metabolite is a
de-esterifed product, ritalinic acid (RA), which accounts for 80% of
the dosage and has a half-life of about 8 h [11]. Reviews over pharmacy
databases and treatment studies have shown that the incidences of
medication discontinuation or non-adherence is between 13.2% and
64% [12]. Te clinical laboratory has an important role in being able to
detect MPH in serum and its metabolite RA in urine.
Various analytical methods such as immunoassay [13], HPLC
with UV detection [14] and more recently liquid chromatography–
electrospray ionization mass spectrometry [15-17], have been proposed
for measuring MPH (in serum).
Tis study was meant to develop and validate a novel HPLC–SPE
method with samples throughput for determinations of MPH in human
serum. In these applications solid phase extraction (SPE) sample
preparation procedures were used. Te method outline with a selective
chromatography in combination with specifc UV detection fulflls the
high quality standard required for accurate determinations in serum
samples from human.
Experimental
Materials
MPH (Figure 1) was purchased from Cerillant (Texas, USA) as 1
mg/mL solutions in methanol and RA (Figure 1) from Sigma-Aldrich
(Australia). HPLC grade acetonitrile was purchased from Termo
Fisher (Cambridge, UK), ammonium formate and dimethyloctylamine
(DMOA) from Sigma-Aldrich (Germany), and HPLC grade methanol
and reagent grade 89-91% pure formic acid from BDH (Poole, UK).
*Corresponding author: Mehdi Rajabnia Khansari, Research Center,
Faculty of Pharmacy, Shahid Beheshti University of Medical Sciences,
Tehran, Iran, E-mail: rajabniamahdi@yahoo.com
Received February 11, 2017; Accepted February 23, 2017; Published February
28, 2017
Citation: Khansari MR, Shahreza S, Rezvanirad A, Nikavar A, Bikloo S, et al.
(2017) Synthesis of Surface Molecularly Imprinting Polymers for Methylphenidate
and its Application in Separating Methylphenidate. J Anal Bioanal Tech 8: 351. doi:
10.4172/2155-9872.1000351
Copyright: © 2017 Khansari MR, et al. This is an open-access article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
Abstract
In this study, a novel approach is proposed for determination of methylphenidate in biological fuids. In this
method molecularly imprinted solid-phase extraction (MISPE), as the sample extraction technique, combined with
high-performance liquid chromatography (HPLC) is used. The water-compatible molecularly imprinted polymers
(MIPs) were prepared using methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linker,
Hexane as porogen and methylphenidate as template molecule. Extraction of methylphenidate from human serum
was carried out using a novel imprinted polymer as the solid-phase extraction (SPE). Various parameters affecting
the extraction effciency of the polymer were evaluated. Also, the optimal conditions for the MIP cartridges were
studied. The limit of detection (LOD) and limit of quantifcation (LOQ) for methylphenidate in serum samples were
1.3 and 10 ng mL
-1
, respectively. The recoveries for serum samples were higher than 92%.
Synthesis of Surface Molecularly Imprinting Polymers for Methylphenidate and
its Application in Separating Methylphenidate
Mehdi Rajabnia Khansari
1,2
, Sara Shahreza
4
, Azam Rezvanirad
1
, Amin Nikavar
2
, Shahrzad Bikloo
3
and Bahareh Sadat Yousefsani
5
1
Faculty of Pharmacy, Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
2
School of Chemical Engineering, Research Center, Iran University of Science and Technology, Tehran, Iran
3
Lorstan University of Medical Sciences, Research Center, Khoramabad, Iran
4
Department of Nanobiotechnology, Tarbiat Modates University, Tehran, Iran
5
Department of Pharmacodynamy and Toxicology, School of Pharmacy, Pharmaceutical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Open Access