A molecularly imprinted polymer （MIP）, prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction （SPE） of cotinine from biological samples has been ...A molecularly imprinted polymer （MIP）, prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction （SPE） of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.展开更多
Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cr...Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.展开更多
A molecular imprinting polymer technique was successfully applied to precipitation polymerization by using styrene as a functional monomer, curcuminoids as templates, acetonitrile as a porogenic solvent,benzoyl peroxi...A molecular imprinting polymer technique was successfully applied to precipitation polymerization by using styrene as a functional monomer, curcuminoids as templates, acetonitrile as a porogenic solvent,benzoyl peroxide as the initiator, and ethylene glycol dimethacrylate as the crosslinker. The effects of interaction on the adsorption capacity of the molecularly imprinted polymer(MIP) and non-imprinted polymer(NIP) were investigated. A comparison of the adsorption capacity for MIP and NIP indicated that the NIP had the lowest adsorption capacity. The curcuminoid-imprinted polymer(Cur-MIP) was synthesized from 0.0237 mmol of styrene, 47.0 g of acetonitrile, 1.0238 mmol of ethylene glycol dimethacrylate, 0.0325 mmol of curcuminoids, and 0.2480 mmol of benzoyl peroxide. A high-performance liquid chromatography method with fluorescence detection was developed and validated for various chromatographic conditions for the determination of the curcuminoids in turmeric samples. The sample solution was separated using the Cur-MIP via solid-phase extraction and analyzed on a Brownlee analytical C_(18) column(150 mm ×6 mm, 5 mm) using an isocratic elution consisting of acetonitrile and 0.1%trichloroacetic acid(40:60, v/v). The flow rate was maintained at 1.5 m L/min. The fluorescence detector was set to monitor at λex? 426 nm and λem? 539 nm. The quantification limit values were found to be16.66, 66.66, and 33.33 mg/L for curcumin, demethoxycurcumin, and bisdemethoxycurcumin, respectively. Thus, we concluded that the Cur-MIP and high-performance liquid chromatographic-fluorescence method could be applied to selective extraction and could be used as a rapid tool for the determination of curcuminoids in medicinal herbal extracts.展开更多
The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction. Molecularly imprinted polymer was prepared from the functional monomer, methacrylic acid and a mi...The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction. Molecularly imprinted polymer was prepared from the functional monomer, methacrylic acid and a mixture of ethanol/dodecanol（90/10, volume ratio） as porogen. It overcomes the common problems of imprin- ting biological polar compounds and shows high selectivity compared favorably with those of non-imprinted polymer and commercially available C18 and silica cartridges in similar aloe emodin tests. Good linearity was obtained be- tween 0.002 and 2.5 mg/mL（r2=0.998） with relative standard deviations below 3.3%.展开更多
A pre-treatment methodology for clenbuterol hydrochloride （CLEN） isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers （MIPs）. CLEN-imprinted pol-...A pre-treatment methodology for clenbuterol hydrochloride （CLEN） isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers （MIPs）. CLEN-imprinted pol- ymers were synthesized by the combined use of ally-β-cyclodextrin （ally-13-CD） and methacrylic acid （MAA）, allyl-β-CD and acrylonitrile （AN）, and allyl-β-CD and methyl methacrylate （MMA） as the binary functional monomers. MAA-linked allyl-β-CD MIPs （M-MAA） were characterized by Fourier transform-infrared （FT-IR） spectroscopy and a scanning electron microscope （SEM）. Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references： AN-linked allyl-β-CD MIPs （M-AN） and MMA-linked allyl-β-CD MIPs （M-MMA）. M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction （MISPE） micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation （RSD） ≤4.45%.展开更多
A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shri...A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.展开更多
基金supported by the National Natural Science Foundation of China(No.20405013)the Scientific Foundation of State Tobacco Monopoly Administration of China(No.110200201017).
文摘A molecularly imprinted polymer （MIP）, prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction （SPE） of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.
基金supported by the Natural Science Foundation of China (41076065)the Major State Basic Research Development Program of China (973 Program) (2010CB428701)
文摘Molecularly imprinted polymers （MIPs） were prepared by the bulk polymerization using crystal violet as the template molecule, and the methacrylic acid and ethylene glycol dimetheacrylate as functional monomer and cross-linker, respectively. Sys- tematic investigations of synthetic conditions were conducted. The surface morphology and recognition mechanism of the obtained polymers were studied using scanning electron microscope and spectrophotometric analysis. MIPs showed high atTmity to template molecule and were successfully applied as special solid-phase extraction sorbent for selective extraction of crystal violet from natural seawater. An off-line molecularly imprinted solid-phase extraction （MISPE） method followed by high-performance liquid chroma- tography with diodearray detection for the analysis of crystal violet was also established. MISPE columns have good recoveries for crystal violet standard solutions and good linearity was obtained over the concentration range of 0-200 ~tg L-1 （R2 〉 0.99）. Finally, two natural seawater samples were investigated. The recoveries of spiked seawater on the MISPE columns were from 44.47% to 62.34%, the relative standard deviation （n=3） being in the range of 2.89%-5.96%.
文摘A molecular imprinting polymer technique was successfully applied to precipitation polymerization by using styrene as a functional monomer, curcuminoids as templates, acetonitrile as a porogenic solvent,benzoyl peroxide as the initiator, and ethylene glycol dimethacrylate as the crosslinker. The effects of interaction on the adsorption capacity of the molecularly imprinted polymer(MIP) and non-imprinted polymer(NIP) were investigated. A comparison of the adsorption capacity for MIP and NIP indicated that the NIP had the lowest adsorption capacity. The curcuminoid-imprinted polymer(Cur-MIP) was synthesized from 0.0237 mmol of styrene, 47.0 g of acetonitrile, 1.0238 mmol of ethylene glycol dimethacrylate, 0.0325 mmol of curcuminoids, and 0.2480 mmol of benzoyl peroxide. A high-performance liquid chromatography method with fluorescence detection was developed and validated for various chromatographic conditions for the determination of the curcuminoids in turmeric samples. The sample solution was separated using the Cur-MIP via solid-phase extraction and analyzed on a Brownlee analytical C_(18) column(150 mm ×6 mm, 5 mm) using an isocratic elution consisting of acetonitrile and 0.1%trichloroacetic acid(40:60, v/v). The flow rate was maintained at 1.5 m L/min. The fluorescence detector was set to monitor at λex? 426 nm and λem? 539 nm. The quantification limit values were found to be16.66, 66.66, and 33.33 mg/L for curcumin, demethoxycurcumin, and bisdemethoxycurcumin, respectively. Thus, we concluded that the Cur-MIP and high-performance liquid chromatographic-fluorescence method could be applied to selective extraction and could be used as a rapid tool for the determination of curcuminoids in medicinal herbal extracts.
文摘The extraction and separation of aloe emodin were optimized via selective molecularly imprinted solid-phase extraction. Molecularly imprinted polymer was prepared from the functional monomer, methacrylic acid and a mixture of ethanol/dodecanol（90/10, volume ratio） as porogen. It overcomes the common problems of imprin- ting biological polar compounds and shows high selectivity compared favorably with those of non-imprinted polymer and commercially available C18 and silica cartridges in similar aloe emodin tests. Good linearity was obtained be- tween 0.002 and 2.5 mg/mL（r2=0.998） with relative standard deviations below 3.3%.
基金Project supported by the Department of Science and Technology of Zhejiang Province(No.2013C02022-2/01),China
文摘A pre-treatment methodology for clenbuterol hydrochloride （CLEN） isolation and enrichment in a complex matrix environment was developed through exploiting molecularly imprinted polymers （MIPs）. CLEN-imprinted pol- ymers were synthesized by the combined use of ally-β-cyclodextrin （ally-13-CD） and methacrylic acid （MAA）, allyl-β-CD and acrylonitrile （AN）, and allyl-β-CD and methyl methacrylate （MMA） as the binary functional monomers. MAA-linked allyl-β-CD MIPs （M-MAA） were characterized by Fourier transform-infrared （FT-IR） spectroscopy and a scanning electron microscope （SEM）. Based upon the results, M-MAA polymers generally proved to be an excellent selective extraction compared to its references： AN-linked allyl-β-CD MIPs （M-AN） and MMA-linked allyl-β-CD MIPs （M-MMA）. M-MAA polymers were eventually chosen to run through a molecularly imprinted solid-phase extraction （MISPE） micro-column to enrich CLEN residues spiked in pig livers. A high recovery was achieved, ranging from 91.03% to 96.76% with relative standard deviation （RSD） ≤4.45%.
文摘A new molecularly imprinted solid-phase extraction（MISPE） monolithic cartridge was synthesized, and MISPE-DLLME（DLLME=dispersive liquid-liquid microextraction） was developed for purification of astaxanthin in shrimp waste. The eluent（methanol） from MISPE was used as the dispersive solvent in subsequent DLLME for further purifying and enriching the analyte prior to high-performance liquid chromatography（HPLC） analysis. The mobile phase was methanol-acetonitrile-water-dichloromethane（85：5：5：5, volume ratio）, flow rate was 0.7 mL/min and UV wavelength was 476 nm. Under optimal conditions, good linearity was obtained in a range of 0.2--200.0 lug/mL（r2=0.9998） with a limit of detection（LOD） of 0.08 Hg/mL, and the extraction recoveries at three spiked levels ranged from 88.3%--92.5% with a relative standard deviation（RSD） less than 4.3%. Moreover, the mean contents of astaxanthin in the three batches of shrimp waste were 95.9, 85.4 and 77.2 μg/g, respectively. This method combining the advantages of MISPE and DLLME results in high selectivity and low cost, which was applied to determining the astaxanthin level in shrimp waste samples.
