Electromembrane extraction of phenytoin from biological fluids: A survey on the effects of molecularly imprinted polymer and carbon nanotubes on extraction efficiency
Introduction
Drug substances determination and quantification are very important in pharmacological and toxicological sciences, pharmacokinetics, forensic studies, and clinical trials. In these kinds of investigations, samples are blood, saliva, spinal fluid, plasma, urine and other biological fluids. These biological fluids are the complex matrices consisting of hundreds/thousands of various components, and the target drug substance (analyte) is mostly in very low concentrations in these samples. Also, sample preparation and analyte extraction are necessary for analysing the analytes of interest in all the mentioned cases [1], [2], [3].
The chemical analysis steps will be influenced by the sample preparation procedure [4,5]. The main role in the sample preparation step is changing the real sample matrix to the appropriate sample for analysis. Meanwhile, a method that follows the following purposes with respect to the type of analyte can be more appropriate: removals of more probable interruptions, analyte concentration increasing, being robust and repeatable independent of sample matrix, using less amounts of sample, less organic solvent volume or not using organic solvent, specific and selective method for target analyte and also compatibility with the instruments [1], [2], [3], [4], [5], [6].
Liquid-liquid extraction and solid phase extraction methods are the most frequently used methods in chemical and pharmaceutical analysis, in order to extract and prepare the samples. These extraction methods disadvantages are considered as a long time sample preparation, organic solvent high consumption, highly-needed sample volume, need to other sample treatment steps, and difficulty in these methods automation. Nowadays, the analytical methods are more concerned for developing the method, which needs extractor (solvent) phase volume to be very lower or solvent-free/solvent less methods to be considered. Therefore, common traditional methods are being replaced with new miniaturized sample preparation methods that were called micro-extraction. Hollow fiber-liquid phase micro-extraction (HF-LPME) is one of the liquid phase microextraction methods that are extensively used, nowadays. Despite of this method simplicity and effectiveness, extraction may time-consuming [7,8]. Therefore, electro-membrane extraction (EME) method was introduced by Pedersen-Bjergaard and Rasmussen in 2006 in order to increase the rate and efficiency [9]. This method was actually the sub-set of the HF-LPME method. At first, a hollow fiber (usually made from polypropylene) was impregnated with a water-immiscible organic solvent which was named supported liquid membrane (SLM). The end of the hollow fiber (HF) was closed and after that its inside was filled by the aqueous solution with definite pH as the acceptor phase. After that, the mentioned HF was put inside the sample aqueous solution with definite pH as the donor phase, and at the final stage, two platinum electrodes were put inside the donor and acceptor phases with respect to the mentioned analyte charge. A magnetic stirrer was utilized to ensure uniformity throughout the container. The extraction was performed by applying electric potential difference (voltage) on two ends of the HF. The driving force achieved by the electric potential difference (voltage) was applied on the width of two donor and acceptor phases. In this method, extraction was performed with respect to active transport, while HF-LPME extraction method was based on passive diffusion. The molecules of analytes distributed between donor phase-SLM and acceptor phase-SLM interphases based on distribution coefficient. Applying the potential difference on both sides of donor and acceptor acts as a driving force, and also could significantly reduce the extraction time [10,11].
The electromembrane extraction method is significantly mentioned for its simplicity, quickness, proper sample clean up, very low consumption of sample and solvent, analyte enrichment, method flexibility, and no requirement to other sample preparation steps [12]. Its reported applications included drug substances [9,[13], [14], [15], [16], [17], [18], [19], [20]], chemicals and dyes [21,22], peptides and amino acids [23], [24], [25], plant hormones [26], heavy metals [27], minerals and anions [28,29] extraction from various foods, environmental samples and also biological fluids.
In addition to this simple method various methods have been invented for EME. These inventions in the method performing included a drop to drop method, on-microchip extraction, pulsed EME, simultaneous extraction of acidic and basic compounds, combination with electro-assisted liquid-liquid microextraction, and carbon nanotubes application in membrane structure [10], [11], [12], [13], [14], [15], [16], [17].
Carbon nanotubes (CNTs) have been applied in various extraction methods as sorbent like solid phase extraction, solid phase micro-extraction (SPME), and HF-LPME [30]. Moreover, several reports were accomplished on their applications in EME method. In those investigations, using carbon nanotubes has increased extraction efficiency due to the high surface area and their adsorption capacity [31,32]. Molecularly imprinted polymers (MIP) with many applications are considered as the porous sorbents made in molecular imprinting method. Also, molecular imprinting is a method for preparing a polymer with selective recognition sites and porosity making. In other words, the selective recognition sites by molecular imprinting make 3D permanent paths and memories for transferring molecules into the polymeric structure [33,34]. In addition, the most important characteristics of molecularly imprinted polymers are their high affinity to the target molecule and their selective absorption capacity [33], [34], [35]. Accordingly, the main applications of molecularly imprinted polymers in field of chemical analysis included using them as the sorbent in SPE, chromatography column, and electrochemical sensors.
In this research, an EME-HPLC-UV method has been developed and validated for phenytoin (PT) determination in human biological fluids. Also, the effects of important factors like organic solvent composition, pH of donor and acceptor solutions, extraction time and voltage on extraction efficiency have been examined. The appropriate conditions optimization for EME method was performed using Box-Behnken experimental design approach. In addition, some nano-sorbents like carbon nanotubes (CNT/EME) and molecularly imprinted polymer (MIP/EME) and their effects on membrane performance and extraction efficiency were also evaluated. At the Final stage, the developed EME-HPLC-UV method were used for drug determination in human plasma and urine samples.
Phenytoin (PT) (5, 5-diphenylimidazolidine-2, 4-dione) is an antiepileptic drug belonged to the class of hydantoin that is frequently utilized for treating seizure and epilepsy. In addition, phenytoin is used in order to prevent the caused seizure by head trauma and brain surgeries. The phenytoin chemical structure and physiochemical characteristics are indicated in Fig. 1. A proper analytical method development for phenytoin determination and quantification in biological fluids is important, because of its pharmacokinetic properties and the extensive prescription for treating the epilepsy, narrow therapeutic index, and also the importance of therapeutic drug monitoring [36].
Several analytical methods have been reported for the phenytoin determination in biological fluids including HPLC [37], [38], [39], [40], [41], LC–MS and LC–MS/MS [42], GC and GC–MS [43,44], immunoassays [45] and capillary electrophoresis [46].
There is no report in literature about using EME method for phenytoin extraction from biological samples. Therefore, an EME method development, and after that, a simple HPLC-UV analysis will be useful for the phenytoin quantitative analysis in biological samples. The proper speed and simplicity, consumption of low volume of organic solvent (<30 µL), proper analyte enrichment and preconcentration, sample clean up, and removing the further sample preparation steps are recognized as the proposed EME method advantages.
Section snippets
Chemicals and materials
Phenytoin (PT) powder (99%) was kindly supplied by Alhavi Pharmaceutical Company (Tehran, Iran). Phenobarbital powder (99%) was supplied from Nantong Pharmaceutical Company (China). Methanol, ethanol, ammonium acetate, glacial acetic acid, hydrochloric acid (HCl), sodium hydroxide (NaOH), nitric acid, sulfuric acid, 2-ethylhexanol, 1-heptanol, 1-octanol, cetyl trimethylammonium bromide (CTAB), toluene, acrylamide, ethylene glycol dimethacrylate (EGDMA), azobisisobutyronitrile (AIBN) and Triton
SLM composition
The effect of various solvents as SLM was examined on phenytoin extraction in similar conditions. Moreover, some solvents combination effect was evaluated as SLM. Test results are indicated in Fig. 3. The maximum extraction was observed for 1-octanol as SLM amongst various solvents. Comparing the statistical results (p value < 0.05) demonstrated the significant difference between the maximum points obtained by 1-octanol from the other points. Also, extraction system was very unstable and high
Optimization of EME of phenytoin
In this research, several factors effect has been examined on EME of phenytoin, in order to obtain the optimum extraction conditions. Also, the SLM composition effect was examined by one factor at a time (OFAT) method. The other parameters like voltage, pH of the donor solution, and extraction time were optimized by the use of Box-Behnken experimental design.
The maximum extraction was observed by 1-octanol amongst various solvents. By comparing the statistical results, the significant
Conclusion
An efficient EME-HPLC-UV method has been developed and validated for the phenytoin determination in biological fluids. Also, effective parameters including SLM composition, applied voltage, donor and acceptor solution pH, and extraction time were evaluated and optimized. In addition, the effects of some solid nano-sorbents like carbon nanotubes and molecularly imprinted polymer on electromembrane extraction efficiency were completely explained. The proposed EME-HPLC-UV method can be applied in
Declaration of Competing Interest
There is no conflict to declare.
Acknowledgements
The authors would like to acknowledge financial and instrumental supports from Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran (Grant No. 32968).
References (54)
- et al.
A review of current trends and advances in modern bio-analytical methods: chromatography and sample preparation
Anal. Chim. Acta
(2009) - et al.
Sample preparation in analysis of pharmaceuticals
TrAC Trend. Anal. Chem.
(2007) New trends in sample preparation for clinical and pharmaceutical analysis
TrAC Trend. Anal. Chem.
(2003)Before the injection—modern methods of sample preparation for separation techniques
J. Chromatogr. A
(2003)- et al.
Environmental and bioanalytical applications of hollow fiber membrane liquid-phase microextraction: a review
Anal. Chim. Acta
(2008) - et al.
Electrokinetic migration across artificial liquid membranes: new concept for rapid sample preparation of biological fluids
J. Chromatogr. A
(2006) - et al.
Electrical field-induced extraction and separation techniques: promising trends in analytical chemistry–a review
Anal. Chim. Acta
(2014) - et al.
Microextraction across supported liquid membranes forced by pH gradients and electrical fields
J. Chromatogr. A
(2007) - et al.
Electrokinetic migration across artificial liquid membranes: tuning the membrane chemistry to different types of drug substances
J. Chromatogr. A
(2006) - et al.
Low-voltage electromembrane extraction of basic drugs from biological samples
J. Chromatogr. A
(2008)
Electromembrane extraction
TrAC Trend. Anal. Chem.
Application of electromembrane extraction followed by corona discharge ion mobility spectrometry analysis as a fast and sensitive technique for determination of tricyclic antidepressants in urine samples
Microchem. J.
Study on electrical current variations in electromembrane extraction process: relation between extraction recovery and magnitude of electrical current
Anal. Chim. Acta
Electromembrane extraction of peptides
J. Chromatogr. A
Electromembrane extraction of amino acids from body fluids followed by capillary electrophoresis with capacitively coupled contactless conductivity detection
J. Chromatogr. A
Ultra-trace determination of Cr (VI) ions in real water samples after electromembrane extraction through novel nanostructured polyaniline reinforced hollow fibers followed by electrothermal atomic absorption spectrometry
Microchem. J.
Electro membrane extraction of biological anions with ion chromatographic analysis
Anal. Chim. Acta
Carbon-based sorbents: carbon nanotubes
J. Chromatogr. A
A new method for the enhancement of electromembrane extraction efficiency using carbon nanotube reinforced hollow fiber for the determination of acidic drugs in spiked plasma, urine, breast milk and wastewater samples
J. Chromatogr. A
Development and application of carbon nanotubes assisted electromembrane extraction (CNTs/EME) for the determination of buprenorphine as a model of basic drugs from urine samples
Anal. Chim. Acta
Molecular imprinting for bio-and pharmaceutical analysis
TrAC Trend. Anal. Chem.
Core–shell molecularly imprinted particles
TrAC Trend. Anal. Chem.
useful sorbents for selective extractions
TrAC Trend. Anal. Chem.
Quantification of carbamazepine, carbamazepine-10, 11-epoxide, phenytoin and phenobarbital in plasma samples by stir bar-sorptive extraction and liquid chromatography
J. Pharma. Biomed. Anal.
Monitoring of phenytoin in human breast milk, maternal plasma and cord blood plasma by solid-phase extraction and liquid chromatography
J. Pharma. Biomed. Anal.
Determination of free levels of phenytoin in human plasma by liquid chromatography/tandem mass spectrometry
J. Pharma. Biomed. Anal.
Electrokinetic migration of acidic drugs across a supported liquid membrane
J. Chromatogr. A
Cited by (13)
Electromembrane extraction (EME): Fundamentals and applications
2023, Talanta OpenFunctional materials and chemicals in electromembrane extraction
2022, TrAC - Trends in Analytical ChemistryCitation Excerpt :The above experiments demonstrated that CBNPs could enhance the mass transfer and stability of EME. Meanwhile, due to the high affinity between CBNPs and analytes, drop in EME efficiency has also been reported [29,34–37]. In these works, CBNPs in the SLM solvent acted as a physical barrier to hinder the mass transfer of analytes through the SLM.
Electromembrane extraction of polar substances – Status and perspectives
2022, Journal of Pharmaceutical and Biomedical AnalysisCitation Excerpt :Recently, carbon-based nanomaterials have emerged as novel extraction phases, mainly for sorptive extractions [142], but they have also been applied in EME. These materials include carbon nanotubes (CNTs) [143–149], fullerene [150], and graphene-based materials. In EME, CNTs and fullerene have so far only been applied for extraction of non-polar analytes, and are therefore outside the scope of this review.
Hydroxytyrosol magnetic molecularly imprinted polymers as the sorbent for solid-phase extraction for selective recognition of hydroxytyrosol from Chinese olive leaves
2021, Materials Today CommunicationsCitation Excerpt :Therefore, it was widely used in many fields, such as chromatographic separation [20–22], solid phase extraction [23,24], biomimetic sensing [25], chemical and biochemical sensing [26,27], and simulated enzyme catalysis [28]. In recent years, many applications of molecular imprinting technology on the surface of nanomaterials had also been reported, such as carbon nanotubes [29,30], Fe3O4 nanoparticles [31,32], and metal organic frameworks [33,34], which had attracted widespread attention due to special properties of physical and chemical, and good effects. Among them, magnetic molecular imprinting technology had developed rapidly because of its ability to avoid complicated operations such as centrifugation and filtration, such as amphiphilic magnetic adsorbent [35], new bayberry honeycomb magnetic surface molecular imprinting [36] and magnetic halloysite nanotube molecular imprinting polymer [37].
Exploring electromembrane extraction and liquid membrane for efficient removal of heavy metals from aqueous solutions: An overview
2024, Environmental Engineering Research