Analytical Methods
·
2013
·Vol. 6
·期 5
·1427-1434
·
IF 1.855
Ruifang Qi,Haochen Jiang,Shuxia Liu,Qiong Jia
In this study, a graphene-modified poly(butyl methacrylate–ethylene dimethacrylate) monolithic column was successfully utilized for purification and enrichment of four pesticides (fludioxonil, cyprodinil, flusilazole, and triflumizole) in fruit and vegetable samples. Several experimental parameters affecting the extraction efficiency were investigated, such as sample pH, sample flow rate, sample volume, salt concentration, eluent type, and eluent flow rate. Combined with HPLC analysis under the optimized conditions, good linearities were obtained for all targets with R2 values greater than 0.9965. The limits of detection (S/N = 3) for four pesticides were found to be in the range of 0.93–3.0 μg kg−1. The intra-day and inter-day relative standard deviations, ranging from 3.4% to 6.2%, were within an acceptable scope. Compared with direct HPLC analysis and preconcentration with unmodified poly(butyl methacrylate–ethylene dimethacrylate) monolith, the incorporation of graphene into the monolith increased the enrichment capacity for the analytes. The developed method was successfully applied to the determination of pesticides in fruit and vegetable samples (apple, grape, orange, tomato, cucumber, rape). The recoveries of four pesticides at different spiked levels in the samples were in the range of 70.2–95.0% with the relative standard deviations less than 6.4%.
研究领域:
分析化学
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环境科学
·
食品科学
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DOI
高影响因子
ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2021
·Vol. 414
·期 18
·5255-5262
·
IF 4.157
Qian Hai-Long,Liu Fang,Liu Xue,Yang Cheng,Yan Xiu-Ping
The separation of amino acid (AA) enantiomers shows significance for chemistry, food, and biology, but remains challenging due to their similar properties. A promising nanoporous chiral covalent organic framework (COF) as a stationary phase for high-performance liquid chromatography (HPLC) suffers from the irregularity and widely distributed particle size of the chiral COF. Herein, we show the facile preparation of a chiral COF-monolith as a stationary phase for HPLC enantiomeric separation of AAs via orthogonal experiments. The CTzDa-monolith is prepared by the incorporation of the model chiral COF named CTzDa into the porous poly(ethylene dimethacrylate-co-methacrylate) monolith and reveals great permeability and mechanical stability. The corresponding CTzDa-monolithic column gives better chiral HPLC separation of AAs than the commercial Poroshell 120 chiral-T column. Thermal dynamic analysis and molecular docking calculations imply the involvement of stereoscopic hydrogen, π-π, and van der Waals interactions between the CTzDa and AAs during HPLC enantioseparation. The facile incorporation of the chiral COF into the porous monolith will promote the potential of a chiral COF as a stationary phase for HPLC. Graphical abstract
研究领域:
分析化学
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材料科学
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生物化学
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2025
·
IF 4
Qi Peng,Yan Ye,Xinglin Wu,Chenchen Lin,Xucong Lin,Qibiao Weng,Qinai Chen
Developing a functional media for precise identification of trace shellfish toxin would underpin the effective assessment of marine pollution. Herein, a novel monolithic column with a dual-mode strategy integrating antifouling and aptamer bionic affinity recognition was proposed for online specific identification of the marine toxin okadaic acid (OA). The zwitterionic monomer 2-(methacryloyloxy)ethylphosphorylcholine (MPC) and aptamers were synergistically employed to enable efficient reduction of matrix interferences and selective capture of target OA. Preparation optimization, characterization, and fouling-resistant mechanism of the dual-mode bionic monolith were evaluated. The zwitterion phosphorylcholine MPC introduced into the monolith significantly improved the fouling resistance to biomass substrates, meanwhile the aptamers were able to provide a high specific recognition capacity. Coupled with LC-MS, the as-prepared monolith provided an effective approach for highly selective and sensitive identification of OA. Good recovery yields of over 90% in shellfish tissue extracts and human serum were achieved with a sensitive limit of detection (LOD) as low as 0.1 ng/mL, as well as excellent specificity and low interference from proteins, fatty acids and analogues. Applied to popular shellfishes (such as clams, mussels, and oysters) and serum samples, trace OA toxin was accurately distinguished and quantified with satisfactory recoveries as 93.8 ± 2.2% – 99.8 ± 2.0% (n=3). Compared to the traditional HLB cartridge and other materials in the LC-MS method, the resulting anti-fouling aptamer monolith provided a more advanced online analysis mode with higher sensitivity and better resolution of OA in biological samples. It might provide an attractive access to an online bionic recognition platform with LC-MS for efficient, anti-interference and sensitive specific detection of trace marine toxin OA in biological samples.
研究领域:
分析化学
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环境科学
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海洋生物学
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DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2013
·
IF 2.591
Jiangmei Li,Haiyun Zhai,Zuanguang Chen,Qing Zhou,Zhenping Liu,Zihao Su
A novel method combining molecular imprinting and SPE was developed in a capillary column for the determination of auramine O in shrimp. The capillary monolithic column was prepared by UV-initiated in situ polymerization, using auramine O as template and methacrylic acid and ethylene dimethacrylate as functional monomer and cross-linker, respectively. The properties of the prepared capillary monolithic column were investigated under the optimized conditions coupled with HPLC, and then the morphologies of the inner polymers were characterized by SEM. The calibration curve was expressed as A = 103 C + 19.8 ( r = 0.9992) with a linear range of 0.25–25.0 μg/mL, and the recoveries of auramine O at different concentrations in shrimp ranged from 90.5 to 92.4% with RSDs ranging from 2.1 to 4.4%. The capacities of the molecularly imprinted polymer and nonimprinted polymer columns were 0.722 and 0.147 μg/mg, respectively, and the LOD (S/N = 3) of auramine O in shrimp was 17.85 μg/kg. Under the selected conditions, the enrichment factors obtained were higher than 70-fold. The results indicate that the prepared molecularly imprinted capillary monolithic column was reliable and applicable to the analysis of auramine O in shrimp.
研究领域:
分析化学
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食品安全
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Lin Zhang,Beibei Chen,Man He,Xiaolan Liu,Bin Hu
In this study, the hydrophilic polymer monolithic capillary (poly(acrylamide-vinylpyridine-methylene bis(acrylamide)), poly(AA-VP-Bis)) was prepared for the separation and enrichment of carboxyl group-containing gold nanoparticles (Au NPs) from environmental waters followed by online ICPMS determination. The extraction mechanism of the prepared poly(AA-VP-Bis) monolithic capillary for Au NPs is based on the static electrical and hydrogen bond interactions between the carboxyl group on the surface of Au NPs and pyridine/amide groups on the surface of the monolith. Under the optimal conditions, a detection limit of 24.2 fmol L–1 and a sample throughput of 6 h–1 were achieved for 3 nm citrate stabilized Au NPs, and the original morphology of the Au NPs could be maintained during the extraction process. The developed method was successfully applied for the analysis of carboxyl group-containing Au NPs in environmental water samples, such as tap water, the Yangtze River water, and the East Lake water, with recoveries in the range of 77–103%. Compared with the reported approaches for analysis of Au NPs, this method is an online strategy for carboxyl group-containing Au NPs determination and has the merits of low detection limit, small sample consumption, fast extraction/desorption kinetics, wide linear range, high selectivity, and high throughput.
研究领域:
分析化学
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF LIQUID CHROMATOGRAPHY & RELATED TECHNOLOGIES
·
2018
·
IF 0.827
Huihui Wu,Hanying Jin,Guangxin Yuan,Jacques Crommen,Jing Zhang,Qiqin Wang
Urea and allantoin are two important additives in cosmetic products for the treatment of dry skin as well as for skin protection and regeneration. In this research, a highly hydrophilic monolith prepared by co-polymerization of N,N-dimethyl-N-acryloyloxyethyl-N-(3-sulfopropyl)ammonium betaine (SPDA) and N,N’-methylenebisacrylamide (MBA) was first exploited for the simultaneous quantification of urea and allantoin in cosmetic products by nano-HPLC in the HILIC mode. The whole separation process could be completed within six minutes using isocratic elution. Due to the extremely high hydrophilicity of this monolithic column, a relatively low content (80%) of ACN in the mobile phase was required to achieve satisfactory separation, and therefore the solubility problems for polar compounds was also avoided in comparison with previously reported results on the commercial columns. Method validation was also accomplished with respect to linearity, reproducibility, selectivity, recovery, stability, LOD and LOQ. The recoveries of urea and allantoin from spiked cosmetic samples were 95.6%-100% and 94.1%-99.9%, respectively. Validation results indicate that this HILIC method based on the miniaturized poly(SPDA-co-MBA) monolith can be applied successfully to the fast and efficient determination of urea and allantoin in cosmetic samples. The miniaturized column format, the low sample consumption (20 nL), and excellent separation efficiency could make this highly hydrophilic monolith an attractive choice for the detection of trace polar analytes from complex samples in future.
研究领域:
分析化学
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化妆品科学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY A
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2012
·
IF 4.531
Xiu-Li Wang,Ying Zhu,Qun Fang
In this work, we developed a microfluidic chip-based liquid chromatography (LC) system with valveless gated sample injection method and monolithic columns. The valveless LC system consisted of a microchip with a separation column and a balance column, two syringe pumps and a laser induced fluorescence detector. Nanoliter-scale sample injection was achieved by simply switching the ON and OFF states of the syringe pumps under gated injection mode, without the need of any mechanical valve. The balance column facilitated the gated injection process by balancing the back pressure in the sample channel with that in the separation channel. Under the gated injection mode, the sample injection volumes could be varied in the range of 0.4–2.4 nL. We investigated the effects of the mobile-phase composition, flow rate , and the sample injection volume on the performance of the LC system. Under the optimized conditions, two fluorescently labeled amines were successfully separated in less than 220 s with a column length of 1 cm. Theoretical plates ranging from 35,700 to 29,400 per meter, corresponding to plate heights ranging from 28 to 34 μm were obtained. The advantages of the present system include simple system structure, ease of operation, convenience for varying injection volume, and high sample loading capacity.
研究领域:
分析化学
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生物工程
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DOI
PubMed
高影响因子
Analytical Methods
·
2020
·Vol. 12
·期 46
·5635-5641
·
IF 2.596
Dan Liu,Lili Meng,Liping Huang,Shipeng Luo,Guohua Zhang
Chitosan is a considerably versatile and promising biomaterial and can easily form a 3D hierarchical porous scaffold. In this work, a novel boronate-affinity monolithic column modified with a boronic acid–chitosan complex was prepared and characterized by different methods such as Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis, specific surface area analysis and pore size distribution analysis. The synthesized monolithic column was used for polymer monolithic microextraction combined with high performance liquid chromatography for the simultaneous determination of cytidine, uridine, inosine, and guanosine in milk powder samples. Several parameters affecting extraction efficiency, including the eluent proportion, eluent flow rate, sample flow rate, sample volume, and sample pH were investigated. The boronate-affinity monolithic column showed high enrichment ability due to the selective formation of cyclic borate esters between nucleosides and boronic acid groups at high pH and the release of cyclic borates at low pH values. Under the optimum operating conditions, the linear range was 0.1–50 μg mL−1, and the correlation coefficients were in the range of 0.9993–0.9994. The LOD and LOQ were in the range of 0.0027–0.0034 and 0.0090–0.011 μg mL−1, respectively. In addition, the results of recovery and relative standard deviation were satisfactory.
研究领域:
分析化学
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材料科学
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生物技术
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2013
·
IF 4.612
Wenjing Niu,Lijuan Wang,Ligai Bai,Gengliang Yang
A new polymeric monolith was synthesized in fused-silica capillary by in situ polymerization technique. In the polymerization, bisphenol A epoxy vinyl ester resin (VER) was used as the functional monomer, ethylene glycol dimethacrylate (EDMA) as the crosslinking monomer, 1,4-butanediol, 1-propanol and water as the co-porogens, and azobisisobutyronitrile (AIBN) as the initiator. The conditions of polymerization have been optimized. Morphology of the prepared poly (VER-co-EDMA) monolith was investigated by the scanning electron microscopy (SEM); pore properties were assayed by mercury porosimetry and nitrogen adsorption. The optimized poly (VER-co-EDMA) monolith showed a uniform structure, good permeability and mechanical stability. Then, the column was used as the stationary phase of high performance liquid chromatography (HPLC) to separate the mixture of benzene derivatives. The best column efficiency achieved for phenol was 235 790 theoretical plates per meter. Baseline separations of benzene derivatives and halogenated benzene compounds under optimized isocratic mode conditions were achieved with high column efficiency. The column showed good reproducibility: the relative standard deviation (RSD) values based on the retention times ( n = 3) for run-to-run, column-to-column and batch-to-batch were less than 0.98, 1.68, 5.48%, respectively. Compared with poly (BMA-co-EDMA) monolithic column, the proposed monolith exhibited more efficiency in the separation of small molecules.
研究领域:
分析化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2013
·Vol. 37
·期 5
·587-594
·
IF 2.591
Ting Yang,Chao Ma,Huaixia Chen,Yajie Zhang,Xueping Dang,Jianlin Huang
An IPC-imprinted (IPC is isoprocarb) poly(methacrylic acid)/SiO 2 hybrid monolithic column was prepared and applied for the recognition of the template. The hybrid monolithic column was synthesized in a micropipette tip using methyltrimethoxysilane as the inorganic precursor, 3-(methacryloxy)propyltrimethoxysilane as the coupling agent, and ethylene glycol dimethacrylate as the cross-linker. The synthesis conditions, including the porogenic solvent, coupling agent, volume ratio of the inorganic alcoholysate and organic part, were optimized. The prepared monolithic column was characterized by SEM and FTIR spectroscopy. A simple, rapid, and sensitive method for the determination of IPC in rice using the imprinted monolithic column microextraction combined with HPLC was developed. Several parameters affecting the sample pretreatment were investigated, including the eluent, washing solution, and loading sample volume. The linearity of the calibration curve was observed in the range of 9.0–1000 μg/kg for IPC in rice with the correlation coefficient ( r 2 ) of 0.9983. The LOD was 3.0 μg/kg (S/N = 3). The assay gave recovery values ranging from 91 to 107%. The proposed method has been successfully applied for the selective extraction and sensitive determination of IPC in rice and a satisfactory result was obtained.
研究领域:
分析化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2024
·Vol. 191
·期 10
·1-10
·
IF 5.3
Hong Tingting,Zhou Qi,Liu Yilian,Ji Yibing,Tan Songwen,Zhou Wenhu,Cai Zhiqiang
Innovative chiral capillary silica monoliths (CSMs) were developed based on DNA nanoflowers (DNFs). Baseline separation of enantiomers such as atenolol, tyrosine, histidine, and nefopam was achieved by using DNF-modified CSMs, and the obtained resolution value was higher than 1.78. To further explore the effect of DNFs on enantioseparation, different types of chiral columns including DNA strand containing the complementary sequence of the template (DCT)-modified CSMs, DNF 2 -modified CSMs, and DNF 3 -modified CSMs were prepared as well. It was observed that DNF-modified CSMs displayed better chiral separation ability compared with DCT-based columns. The intra-day and inter-day repeatability of model analytes’ retention time and resolution kept desirable relative standard deviation values of less than 8.28%. DNF 2 /DNF 3 -modified CSMs were able to achieve baseline separation of atenolol, propranolol, 2′-deoxyadenosine, and nefopam enantiomers. Molecular docking simulations were performed to investigate enantioselectivity mechanisms of DNA sequences for enantiomers. To indicate the successful construction of DNFs and DNF-modified CSMs, various charaterization approaches including scanning electron microscopy, agarose gel electrophoresis, dynamic light scattering analysis, electroosmotic flow, and Fourier-transform infrared spectroscopy were utilized. Moreover, the enantioseparation performance of DNF-modified CSMs was characterized in terms of sample volume, applied voltage, and buffer concentration. This work paves the way to applying DNF-based capillary electrochromatography microsystems for chiral separation. Graphical abstract
研究领域:
分析化学
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生物化学
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材料科学
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PubMed
高影响因子
CHROMATOGRAPHIA
·
2012
·Vol. 75
·期 5
·289-296
·
IF 1.195
Zhang Yulin,Huang Liang,Chen Qinhua,Chen Zilin
A silica monolithic column chemically modified with l -pipecolic acid as chiral stationary phase has been developed for chiral separation of dansyl amino acids by capillary electrochromatography–mass spectrometry (CEC–MS). The monolithic column was prepared by a sol–gel process and subsequent chemical modification by l -pipecolic acid as chiral selector with 3-glycidoxypropyltrimethoxysilane as spacer. Interestingly, it was found that the l -pipecolic acid-modified monolithic column can hold copper(II) ions tightly after loading Cu(II) ions during column preparation and conditioning and allows CEC separation to be conducted based on chiral ligand exchange with MS detection by a mobile phase without copper ions. It has been demonstrated that the chiral monolithic column operates well for enantioseparation of several dansyl amino acids by CEC–MS.
研究领域:
分析化学
·
药物化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）