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1.
We describe a molecularly imprinted polymer (MIP) for the solid-phase extraction of the skin protectant allantoin. The MIP was deposited on the surface of monodisperse silica microspheres possessing acroyl groups on the surface (MH-SiO2). The resulting MIP microspheres (MH-SiO2@MIP) showed a 3.4-fold higher adsorption capacity and a 1.9-fold better selectivity for allantoin than the respective non-imprinted polymer (MH-SiO2@NIP). The monolayer adsorption capacities of the MH-SiO2@MIP and the MH-SiO2@NIP were calculated with the help of the Langmuir model and found to be 6.8 and 1.9 mg?g?1, respectively. Adsorption kinetics fit a pseudo-second order rate mechanism, with an initial adsorption rate of 1.44 for the MH-SiO2@MIP, and of 0.07 mg?g?1?min?1 for the MH-SiO2@NIP. The material can be regenerated, and its adsorption capacity for allantoin remains stable for at least five regeneration cycles. It was successfully used as a sorbent for the selective solid-phase extraction of allantoin from Rhizoma dioscoreae. Figure
A molecularly imprinted polymer for the selective separation of allantoin was developed. It was successfully used as a sorbent for the selective solid-phase extraction of allantoin from Rhizoma dioscoreae. 相似文献
2.
以橄榄醇为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,甲苯和十二醇为溶剂,通过本体聚合法制备了橄榄醇分子印迹聚合物。利用平衡结合实验、扫描电镜(SEM)及红外光谱(FTIR)对分子印迹聚合物(MIP)进行了表征,并用该聚合物进行了加标麦麸中橄榄醇的固相萃取(SPE)研究。平衡结合实验表明MIP对模板分子具有更好的识别性。Scatchard分析表明对橄榄醇分子的吸附存在2类不同结合位点,其中高亲和力结合位点和低亲和力结合位点的解离常数分别为0.021和1.002 mmol/L,相应的最大表观结合量分别为18.74和135.9 μmol/g。在优化的固相萃取条件下,MIP固相萃取柱对加标麦麸中橄榄醇的回收率达到97.8%~98.8%,相对标准偏差为2.8%~4.2%(n=5),线性范围为0.1~100 mg/L,检出限(S/N=3)为0.062 mg/L。与非印迹聚合物(NIP)柱及市售聚苯乙烯/二乙烯基苯(PLS)柱相比,MIP柱的选择性更强,回收率更高,纯化效果更好。 相似文献
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Saman Azodi-Deilami Majid Abdouss Seyed Alireza Hasani 《Central European Journal of Chemistry》2010,8(4):861-869
In this paper, a highly selective molecularly imprinted polymer (MIP) for tramadol hydrochloride, a drug used to treat moderate
to severe pain, was prepared and its use as solid-phase extraction (SPE) sorbent was demonstrated. The molecularly imprinted
solid-phase extraction procedure followed by high performance liquid chromatography with ultraviolet detector (MISPE-HPLC)
was developed for selective extraction and determination of tramadol in human plasma and urine. The optimal conditions for
molecularly imprinted solid-phase extraction (MISPE) consisted of conditioning with 1 mL methanol and 1 mL of deionized water
at neutral pH, loading of tramadol sample (50 μg L−1) at pH 7.5, washing using 1 mL acetone and elution with 3 × 1 mL of 10% (v/v) acetic acid in methanol. The MIP selectivity
was evaluated by checking several substances with similar molecular structures to that of tramadol. Results from the HPLC
analyses showed that the calibration curve of tramadol (using MIP from human plasma and urine) is linear in the ranges of
6–100 and 3–120 μg L−1 with good precisions (1.9% and 2.9% for 5.0 μg L−1), respectively. The recoveries for plasma and urine samples were higher than 81%.
相似文献
5.
Predicting the performance of molecularly imprinted polymers: Selective extraction of caffeine by molecularly imprinted solid phase extraction 总被引:2,自引:0,他引:2
A rational design approach was taken to the planning and synthesis of a molecularly imprinted polymer capable of extracting caffeine (the template molecule) from a standard solution of caffeine and further from a food sample containing caffeine. Data from NMR titration experiments in conjunction with a molecular modelling approach was used in predicting the relative ratios of template to functional monomer and furthermore determined both the choice of solvent (porogen) and the amount used for the study. In addition the molecular modelling program yielded information regarding the thermodynamic stability of the pre-polymerisation complex. Post-polymerisation analysis of the polymer itself by analysis of the pore size distribution by BET yielded significant information regarding the nature of the size and distribution of the pores within the polymer matrix. Here is proposed a stepwise procedure for the development and testing of a molecularly imprinted polymer using a well-studied compound—caffeine as a model system. It is shown that both the physical characteristics of a molecularly imprinted polymer (MIP) and the analysis of the pre-polymerisation complex can yield vital information, which can predict how well a given MIP will perform. 相似文献
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Molecularly imprinted polymers (MIPs) were synthesized in 24-well glass fiber membrane filter plates to obtain a novel type of solid phase extraction device for the cleanup of propranolol. Sample processing parameters like residence time during sample loading, sample volume, pH, sample solvent, type and amount of washing and elution solvents were investigated and optimized. Important differences from the traditional molecularly imprinted solid phase extraction (MISPE) cartridges have been identified. The MIP modified composite membrane suits well for the sample preparation of low volume biological samples. A protocol has been elaborated for the quantitation of propranolol from urine and plasma samples in the clinically relevant concentration ranges. Preliminary validation results indicate that the composite MIP membrane filter plates offer a viable alternative to existing MISPE cartridges and at the same time have advantages like much easier and faster synthesis method and high-throughput analysis. 相似文献
9.
Eduardo Costa Figueiredo Csar Ricardo Teixeira Tarley Lauro Tatsuo Kubota Susanne Rath Marco Aurlio Zezzi Arruda 《Microchemical Journal》2007,85(2):290-296
A molecularly imprinted polymer has been synthesized for a selective on-line catechol extraction, followed by its spectrophotometric determination in guarana powder, mate tea and tap water samples. A clean-up column, containing a methacrylic polymer + C18 solid phase, was also used in order to enhance selectivity. The imprinted polymer was prepared by bulk polymerization using catechol as template and 4-vinylpyridine as the functional monomer. Permanganate solution was used as spectrophotometric reagent, where Mn(VII) was reduced to Mn(II) by catechol in an acid medium, causing color loss, which was monitored at 528 nm. Physical (extraction flow rate, elution flow rate, coil length) and chemical (nature and concentration of the eluent, potassium permanganate concentration) variables were optimized, and the selectivity was appraised using three molecules (4-chloro-2-methylphenol, 2-cresol, 2-methoxyphenol) similar to catechol. These molecules did not present interference in 1:8, 1:10 and 1:10 (catechol/concomitant) proportions, respectively. The analytical calibration curve ranged from 3.0 up to 100 μmol L− 1 (r > 0.999; seven concentrations levels, n = 3) and the limits of detection (LOD) and quantification (LOQ) were 0.8 and 2.7 μmol L− 1, respectively. Precision, expressed as RSD, was of 3.0% (20 μmol L− 1, n = 10), and the analytical frequency was 15 h− 1. Accuracy was checked by the HPLC technique and the results did not present significant difference at 95% confidence levels according to the t test. 相似文献
10.
以吲哚美辛(IDM)为模板分子,丙烯酰胺(AA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,本体聚合法制备过程中加入纳米胶体金,合成了吲哚美辛胶体金分子印迹聚合物(MIPs/Au),利用MIPs/Au表面胶体金对蛋白吸附作用,将抗吲哚美辛的多克隆抗体固定在MIPs/Au上,得到表面固定有抗体的新型聚合物(MIPs/Au-Ab)并对其进行了表征。制备了填充材料为MIPs/Au-Ab的固相萃取柱并对其上样、淋洗和洗脱条件进行了优化,并将所制备的新型萃取柱用于水样中IDM的分离富集。抗吲哚美辛抗体交联在聚合物表面,不仅增加了萃取柱的特异性吸附容量,而且有效地降低了MIP的非特异性吸附。 相似文献
11.
Chuande Zhao Ting Zhao Xiaoyan Liu Haixia Zhang 《Journal of chromatography. A》2010,1217(45):6995-7002
A novel molecularly imprinted polymer was synthesized with attapulgite employed as matrix, which is simple and time-saving. In this method, sudan I was chosen as template molecule, 2-vinylpyridine as functional monomer and ethylene glycol dimethacrylate as cross-linking agent, respectively. The imprinted polymer was characterized by the infrared spectroscopy and transmission electron microscopy. Then the selectivity experiments were performed on sudan dyes and the recognition coefficients for sudan I, sudan II, sudan III and sudan IV were 2.9, 1.9, 1.9 and 2.3, respectively. As the packing material of solid-phase extraction, the imprinted polymer has been applied to on-line concentration of the four sudan dyes in samples from Yellow River water, tomato sauce and sausage. The corresponding analytical methods to determine these sudan dyes have been developed. The limits of detection for these sudan dyes were in the range of 0.01–0.05 ng mL−1 for Yellow River water, 1.0–3.0 ng g−1 for tomato sauce and 0.8–3.0 ng g−1 for sausage. 相似文献
12.
Yin X Liu Q Jiang Y Luo Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(1):191-196
A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C(18)-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata (Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9±0.6 μmol/g and 12.1±0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n=5) and 96.0% and 104.2% (RSD 2.9-3.7%, n=5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment. 相似文献
13.
A new polymeric sorbent prepared by utilizing molecular imprinting technology was used for the selective extraction of hydrochlorothiazide (HCT) from pharmaceutical and human serum sample. The molecularly imprinted polymer (MIP) was prepared using HCT as the template, methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the cross-linker monomer, and dimethylformamide (DMF) as a solvent. The optimized conditions of MIPs as a selective sorbent for the preconcentration of the HCT were studied. The results showed that the drug could be quantitatively and selectively maintained in the column to be then eluted from the sorbent by using methanol-acetic acid mixture (9:1). HCT could be determined spectrophotometrically at λmax = 270 nm. This method made it possible to quantitize HCT in the range of 0.1–21.0 μg ml-1, by less than 0.55% of RSD%, with a detection limit (S/N = 3) of 0.073 ng ml-1. The preconcentration factor of 1000, recoveries of up to 96% and retention capacity of 75.0 mg g-1 were achieved using this technique. 相似文献
14.
Synthesis of surface molecularly imprinted polymer and the selective solid phase extraction of imidazole from its structural analogs 总被引:1,自引:0,他引:1
A surface molecularly imprinted polymer (MIP) was synthesized by using imidazole as the template and modified silica particles as the support material. The static adsorption, solid phase extraction (SPE) and high-performance liquid chromatography (HPLC) experiments were performed to investigate the adsorption properties and selective recognition characteristics of the polymer for imidazole and its structural analogs. It was shown that the maximum binding capacities of imidazole on the MIP and the non-imprinted polymer (NIP) were 312 and 169 μmol g−1, respectively. The adsorption was fast and the adsorption equilibrium was achieved in 30 min. The binding process could be described by pseudo-second order kinetics. Compared with the corresponding non-imprinted polymer, the molecularly imprinted polymer exhibited much higher adsorption performance and selectivity for imidazole. The selective separation of imidazole from a mixture of 1-hexyl-3-methylimidazolium bromide ([C6mim][Br]) and 2,4-dichlorophenol could be achieved on the MIP-SPE column. The recoveries of imidazole and [C6mim][Br] were 97.6-102.7% and 12.2-17.3%, respectively, but 2,4-dichlorophenol could not be retained on the column. The surface molecularly imprinted polymer presented here may find useful application as a solid phase absorbent to separate trace imidazole in environmental water samples. This may also form the basis for our research program on the preparation and application of alkyl-imidazolium imprinted polymers. 相似文献
15.
Vitor RV Martins MC Figueiredo EC Martins I 《Analytical and bioanalytical chemistry》2011,400(7):2109-2117
A method constituted by molecularly imprinted solid-phase extraction (MISPE) with high-performance liquid chromatography coupled
to diode array detector (HPLC-DAD) was developed for cotinine analysis in saliva samples. For this purpose, the separation
was carried out with a C18 reversed-phase column at 20 °C. The mobile phase which was composed of a mixture of 09:91 (v/v) acetonitrile/phosphate buffer, pH 6.3, was delivered with isocratic flow rate at 1.4 mL min−1. Employing MISPE, the best conditions were achieved with 1.5 mL of saliva plus 1.5 mL of 0.1 mol L−1 of acetate buffer, pH 5.5, which were then passed through a cartridge previously conditioned with 2 mL acetonitrile, 2 mL
methanol, and 2 mL of 0.1 mol L−1 sodium acetate buffer, pH 5.5. The washing was carried out with 1 mL deionized water, 1 mL of 0.1 mol L−1 sodium hydroxide, and 1 mL hexane; finally; the cotinine elution was carried out with 3 mL methanol/water (97.5: 2.5, v/v). Linearity ranged from 30 to 500 ng mL−1 with r > 0.99. Intra-assay, interassay precision, and accuracy ranged from 3.1% to 10.1%, 5.2% to 15.9%, and 99.22% to 111.17%,
respectively. The detection and quantification limits were 10 and 30 ng mL−1, respectively. This investigation has provided a reliable method for routine cotinine determination in saliva, and it is
an important tool for monitoring cigarette smoke exposure in smokers. The method was applied in five smokers’ samples who
consumed around five to 20 cigarettes per day and the values of cotinine in saliva were from 66.7 to 316.16 ng mL−1. 相似文献
16.
Turghun Muhammad Liu Cui Wang Jide Elena V. Piletska Antonio R. Guerreiro Sergey A. Piletsky 《Analytica chimica acta》2012
Novel water-compatible molecularly imprinted polymers (MIPs) selective for amiodarone (AD) were designed via a new methodology which relies on screening library of non-imprinted polymers (NIPs). The NIP library consisted of eighteen cross-linked co-polymers synthesized from monomers commonly used in molecular imprinting. The binding capacity of each polymer in the library was analyzed in two different solvents. Binding in water was used to assess non-specific (hydrophobic) interactions and binding in an appropriate organic solvent was used to assess specific interactions. A good correlation was found between the screening tests and modeling of monomer–template interactions performed using computational approach. Additionally, analysis of template–monomer interactions was performed using UV–vis spectroscopy. As the result, 4-vinylpyridine (4-VP) was selected as the best monomer for developing MIP for AD. The 4-VP-based polymers demonstrated imprinting factor equal 3.9. The polymers performance in SPE was evaluated using AD and its structural analogues. The recovery of AD was as high as 96% when extracted from spiked phosphate buffer (pH 4.5) solution and 82.1% from spiked serum samples. The developed MIP shown as a material with specific binding to AD, comparing to its structural analogues, 1-(2-diethylaminoethoxy)-2,6-diiodo-4-nitrobenzene and lidocaine, which shown 9.9% and 25.4% of recovery from the buffer solution, correspondingly. We believe that the screening of NIP library could be proposed as an alternative to commonly used computational and combinatorial approaches. 相似文献
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Figueiredo EC Sparrapan R Sanvido GB Santos MG Arruda MA Eberlin MN 《The Analyst》2011,136(18):3753-3757
The association of solid phase extraction with molecularly imprinted polymers (MIP) and electrospray ionization mass spectrometry (ESI-MS) is applied to the direct extraction and quantitation of benzodiazepines in human plasma. The target analytes are sequestered by MIP and directly analyzed by ESI-MS. Due to the MIP highly selective extraction, ionic suppression during ESI is minimized; hence no separation is necessary prior to ESI-MS, which greatly increases analytical speed. Benzodiazepines (medazepam, nitrazepam, diazepam, chlordiazepoxide, clonazepam and midazolam) in human plasma were chosen as a proof-of-principle case of drug analyses by MIP-ESI-MS in a complex matrix. MIP-ESI-MS displayed good figures of merits for medazepam, nitrazepam, diazepam, chlordiazepoxide and midazolam, with analytical calibration curves ranging from 10 to 250 μg L(-1) (r > 0.98) with limit of quantification <10 μg L(-1) and acceptable within-day and between-day precision and accuracy. 相似文献
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A molecularly imprinted polymer (MIP) prepared using propranolol as template, methacrylic acid (MA) and ethylene glycol dimethacrylate (EGDMA) was used to develop SPE methods in "reversed-" and normal phase mode for an analogue of propranolol (M47070) with another analogue (M45655) used as an internal standard. The compounds were also extracted in reversed-phase mode onto a non-imprinted polymer. It was necessary to employ a protein precipitation step ahead of MIP-SPE in order to facilitate downstream analysis. High extraction efficiencies and linear calibration ranges were achieved using both reversed-phase (RP) and normal phase (NP) MIP-based methods. Extraction efficiencies were lower on the non-imprinted polymer indicating stronger retention by the MIP. This stronger retention was attributed to selective imprint-based binding by the MIP that was not available for the non-imprinted polymer. Although clean extracts were obtained in both RP and NP modes, low level interference from template-related impurities or degradation products compromised detection of M47070 at low concentrations for the MIP-based methods. This interference made accuracy of the MIP-based methods poorer at low concentrations. The reversed-phase method showed marginally better accuracy and precision than the normal phase method. 相似文献
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A new molecularly imprinted polymer for selective extraction of cotinine from urine samples by solid-phase extraction 总被引:1,自引:0,他引:1
Cotinine, the main metabolite of nicotine in human body, is widely used as a biomarker for assessment of direct or passive
exposure to tobacco smoke. A method for molecularly imprinted solid-phase extraction (MISPE) of cotinine from human urine
has been investigated. The molecularly imprinted polymer (MIP) with good selectivity and affinity for cotinine was synthesized
using cotinine as the template molecule, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as
the cross-linker. The imprinted polymer was evaluated for use as a SPE sorbent, in tests with aqueous standards, by comparing
recovery data obtained using the imprinted form of the polymer and a non-imprinted form (NIP). Extraction from the aqueous
solutions resulted in more than 80% recovery. A range of linearity for cotinine between 0.05 and 5 μg mL−1 was obtained by loading 1 mL blank urine samples spiked with cotinine at different concentrations in acetate buffer of pH
9.0, and by using double basic washing and acidic elution. The intra-day coefficient of variation (CV) was below 7% and inter-day
CV was below 10%. This investigation has provided a reliable MISPE–HPLC method for determination of cotinine in human urine
from both active smokers and passive smokers.
Figure 相似文献
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