Co-reporter:Lijun He, Wenhang Cui, Yali Wang, Wenjie Zhao, Guoqiang Xiang, Xiuming Jiang, Pu Mao, Juan He, Shusheng Zhang
Journal of Chromatography A 2017 Volume 1522(Volume 1522) pp:
Publication Date(Web):3 November 2017
DOI:10.1016/j.chroma.2017.09.047
•New PIL-based magnetic particles were conveniently prepared by LBL assembly method.•The magnetic particles showed homogeneous shapes with high saturation magnetization.•The magnetic particles were utilized as efficient adsorbents in MSPE for pesticides.•The proposed PIL-MSPE-HPLC method was fast, simple, and feasible.In this study, layer-by-layer assembly of polyelectrolyte multilayer films on magnetic silica provided a convenient and controllable way to prepare polymeric ionic liquid-based magnetic adsorbents. The resulting particles were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The data showed that the magnetic particles had more homogeneous spherical shapes with higher saturation magnetization when compared to those obtained by free radical polymerization method. This facilitated the convenient collection of magnetic particles, with higher extraction repeatability. The extraction performance of the multilayer polymeric ionic liquid-based adsorbents was evaluated by magnetic solid-phase extraction of four pesticides including quinalphos, fenthion, phoxim, and chlorpropham. The data suggested that the extraction efficiency depended on the number of layers in the film. The parameters affecting the extraction efficiency were optimized, and good linearity ranging from 2 to 250 μg L−1 was obtained with correlation coefficients of 0.9994–0.9998. Moreover, the proposed method presented low limit of detection (0.5 μg L−1, S/N = 3) and limit of quantification (1.5 μg L−1, S/N = 10), and good repeatability expressed by the relative standard deviation (2.0%–4.6%, n = 5). The extraction recoveries of four pesticides were found to range from 58.9% to 85.8%. The reliability of the proposed method was demonstrated by analyzing environmental water samples, and the results revealed satisfactory spiked recovery, relative standard deviation, and selectivity.
Co-reporter:Qiong Jiang;Qin Liu;Qiliang Chen;Wenjie Zhao;Guoqiang Xiang;Xiuming Jiang;Shusheng Zhang
Journal of Separation Science 2016 Volume 39( Issue 16) pp:3221-3229
Publication Date(Web):
DOI:10.1002/jssc.201600267
Magnetic particles modified with a dicationic polymeric ionic liquid are described as a new adsorbent in magnetic solid-phase extraction. They were obtained through the copolymerization of a 1,8-di(3-vinylimidazolium)octane-based ionic liquid with vinyl-modified SiO2@Fe3O4, and were characterized by FTIR spectroscopy, X-ray diffraction, and vibrating sample magnetometry. The modified magnetic particles are effective in the extraction of organophosphate pesticides and polycyclic aromatic hydrocarbons. Also, they can provide different extraction performance for the selected analytes including fenitrothion, parathion, fenthion, phoxim, phenanthrene, and fluoranthene, where the extraction efficiency is found to be in agreement with the hydrophobicity of analytes. Various factors influencing the extraction efficiency, such as, the amount of adsorbent, extraction, and desorption time, and type and volume of the desorption solvent, were optimized. Under the optimized conditions, a good linearity ranging from 1–100 μg/L is obtained for all analytes, except for parathion (2–200 μg/L), where the correlation coefficients varied from 0.9960 to 0.9998. The limits of detection are 0.2–0.8 μg/L, and intraday and interday relative standard deviations are 1.7–7.4% (n = 5) and 3.8–8.0% (n = 3), respectively. The magnetic solid-phase extraction combined with high-performance liquid chromatography can be applied for the detection of trace targets in real water samples with satisfactory relative recoveries and relative standard deviations.
Co-reporter:Ya-Li WANG, Li-Qin YOU, Yu-Wen MEI, Jian-Ping LIU, Li-Jun HE
Chinese Journal of Analytical Chemistry 2016 Volume 44(Issue 6) pp:942-949
Publication Date(Web):June 2016
DOI:10.1016/S1872-2040(16)60937-4
A benzyl functionalized ionic liquid, 1-benzyl-3-methylimidazolium bis [(trifluoromethyl) sulfonyl] imide ([BeMIM][Tf2N]), was synthesized and used as an extraction solvent of dispersive liquid-liquid microextraction (DLLME) for enrichment and determination of 5 kinds of organophosphorus pesticides (phoxim, fenitrothion, chlorpyrifos, phorate and parathion) and 2 kinds of aromatic compounds (chloronaphthalene and anthracene) in environmental water samples by high-performance liquid chromatography (HPLC). [BeMIM][Tf2N] had higher extraction efficiency than 1-octyl-3-methylimidazolium bis [(trifluoromethyl)sulfonyl] imide and common organic solvents such as carbon tetrachloride and tetrachloroethylene. The extraction was performed using 40 μL of [BeMIM][Tf2N] as respective extraction solvent and 1 mL of methanol as dispersive solvent with centrifugal time of 5 min. Under the optimal conditions, the proposed method exhibited a good linearity for all analytes with correlation coefficients of 0.9994−0.9998. The precision, described as intra-day and inter-day relative standard deviations (RSDs) of five replicate experiments at three different concentrations of 10, 40 and 100 μg L−1, was 1.1%–4.3% and 0.8%–4.8%, respectively. The limits of detection (LODs) were 0.01–1.0 µg L−1 (S/N = 3). The developed method was convenient, rapid and applicable to detection of the analytes in real environmental water samples with satisfactory recovery of 82.7%–118.3% and RSDs of 0.7%–5.6%. Introduction of benzyl group into the imidazolium could considerably elevate the extraction efficiecny of the analytes due to enhanced π-π interaction between [BeMIM][Tf2N] and analytes. [BeMIM][Tf2N] was a satisfactory extraction solvent with a high enrichment factor of 339 and extraction efficiency of 81.4%. The partition coefficients of all analytes in [BeMIM][Tf2N]-DLLME system were determined and the extraction mechanism was discussed.A benzyl functionalized ionic liquid, [BeMIM][Tf2N], was used as extraction solvent for organophosphorus pesticides (OPPs) and aromatic compounds in dispersive liquid-liquid microextraction (DLLME). Introduction of benzyl group into the imidazolium could elevate the extraction efficiecny due to enhanced π-π interaction between [BeMIM][Tf2N] and analytes. [BeMIM][Tf2N] exhibited a high EF of 339 and ER of 81.4%.
Co-reporter:Xiaoyan Zheng, Lijun He, Yajing Duan, Xiuming Jiang, Guoqiang Xiang, Wenjie Zhao, Shusheng Zhang
Journal of Chromatography A 2014 Volume 1358() pp:39-45
Publication Date(Web):5 September 2014
DOI:10.1016/j.chroma.2014.06.078
•A new polymeric ionic liquid modified magnetic nanoparticles (PIL-MNPs) was prepared.•The as-prepared PIL-MNPs were firstly used as an adsorbent in MSPE.•The adsorbent was demonstrated to be highly efficient for enrichment of OPPs.•The PIL-based MSPE process was facile and quick, and the adsorbent was reusable.•The PIL-MSPE–HPLC was successfully applied to detect four OPPs from three tea drink samples.New poly(ionic liquid) immobilized magnetic nanoparticles (PIL-MNPs) were synthesized via co-polymerization of 1-vinyl-3-hexylimidazolium-based ionic liquid and vinyl-modified magnetic particles and were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and magnetic measurements. The PIL-MNPs were utilized as adsorbent phases in magnetic solid-phase extraction (MSPE). The extraction and enrichment efficiency were evaluated by using four organophosphorus pesticides (parathion, fenthion, phoxim and temephos) as test analytes. Various parameters, such as amount of adsorbent, adsorption time, desorption solvent and time, and ionic strength were investigated. The proposed method showed good linearity for the analytes in the concentration range of 1–200 μg L−1 with a correlation coefficient (R) > 0.9963. Low limit of detection of 0.01 μg L−1 and high enrichment factors ranging from 84 to 161 were achieved. The proposed method has been successfully used to determine organophosphorus pesticides from three tea drink samples with satisfactory recovery of 81.4–112.6% and RSDs of 4.5–11.3%. The PIL-MNP adsorbent can be reused for 20 times without a noticeable decrease in extraction efficiency.
Co-reporter:Longhui Liu;Xiuming Jiang;Wenjie Zhao;Guoqiang Xiang;Jared L. Anderson
Journal of Separation Science 2014 Volume 37( Issue 8) pp:1004-1011
Publication Date(Web):
DOI:10.1002/jssc.201301062
In this study, silica modified with a 30-membered macrocyclic polyamine was synthesized and first used as an adsorbent material in SPE. The SPE was further combined with ionic liquid (IL) dispersive liquid–liquid microextraction (DLLME). Five polycyclic aromatic hydrocarbons were employed as model analytes to evaluate the extraction procedure and were determined by HPLC combined with UV/Vis detection. Acetone was used as the elution solvent in SPE as well as the dispersive solvent in DLLME. The enrichment of analytes was achieved using the 1,3-dibutylimidazolium bis[(trifluoromethyl)sulfonyl]imide IL/acetone/water system. Experimental conditions for the overall macrocycle-SPE–IL-DLLME method, such as the amount of adsorbent, sample solution volume, sample solution pH, type of elution solvent as well as addition of salt, were studied and optimized. The developed method could be successfully applied to the analysis of four real water samples. The macrocyclic polyamine offered higher extraction efficiency for analytes compared with commercially available C18 cartridge, and the developed method provided higher enrichment factors (2768–5409) for model analytes compared with the single DLLME. Good linearity with the correlation coefficients ranging from 0.9983 to 0.9999 and LODs as low as 0.002 μg/L were obtained in the proposed method.
Co-reporter:Lijun He, Mingliang Zhang, Wenjie Zhao, Jie Liu, Xiuming Jiang, Shusheng Zhang, Lingbo Qu
Talanta 2012 Volume 89() pp:433-440
Publication Date(Web):30 January 2012
DOI:10.1016/j.talanta.2011.12.057
Co-reporter:Lijun He, Mingliang Zhang, Longhui Liu, Xiuming Jiang, Pu Mao, Lingbo Qu
Journal of Chromatography A 2012 1270() pp: 186-193
Publication Date(Web):
DOI:10.1016/j.chroma.2012.11.007
Co-reporter:Lijun He, Xianli Luo, Xiuming Jiang, Lingbo Qu
Journal of Chromatography A 2010 Volume 1217(Issue 31) pp:5013-5020
Publication Date(Web):30 July 2010
DOI:10.1016/j.chroma.2010.05.057
The paper described a new ionic liquid, 1,3-dibutylimidazolium hexafluorophosphate, as extraction solvent for extraction and preconcentration of organophosphorus pesticides (fenitrothion, parathion, fenthion and phoxim) from water and fruit samples by dispersive liquid–liquid microextraction combined with high-performance liquid chromatography. The effects of experimental parameters, such as extraction solvent volume, disperser solvent and its volume, extraction and centrifugal time, sample pH, extraction temperature and salt addition, on the extraction efficiency were investigated. An extraction recovery of over 75% and enrichment factor of over 300-fold were obtained under the optimum conditions. The linearity relationship was also observed in the range of 5–1000 μg L−1 with the correlation coefficients (r2) ranging from 0.9988 to 0.9999. Limits of detection were 0.01–0.05 μg L−1 for four analytes. The relative standard deviations at spiking three different concentration levels of 20, 100 and 500 μg L−1 varied from 1.3–2.7, 1.4–1.9 and 1.1–1.7% (n = 7), respectively. Three real samples including tap water, Yellow River water and pear spiked at three concentration levels were analyzed and yielded recoveries ranging from 92.7–109.1, 95.0–108.2 and 91.2–108.1%, respectively.
Co-reporter:Lijun He, Jing Zhang, Yinjuan Sun, Jie Liu, Xiuming Jiang, Lingbo Qu
Journal of Chromatography A 2010 Volume 1217(Issue 38) pp:5971-5977
Publication Date(Web):17 September 2010
DOI:10.1016/j.chroma.2010.07.064
A perhydro-26-membered hexaazamacrocycle-based silica (L1GlySil) stationary phase for high-performance liquid chromatography (HPLC) was prepared using 3-glycidoxypropyltrimethoxysilane as coupling reagent. The structure of new material was characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic performance and retention mechanism of the new phase were evaluated in reversed-phase (RP) and normal-phase (NP) modes using different solute probes including aromatic compounds, organophosphorus pesticides, carbamate pesticides and phenols. The results showed that L1GlySil was a sort of multimode-bonded stationary phase with excellent chromatographic properties. The new phase could provide various action sites for different solutes, such as hydrophobic, hydrogen bonding, π–π, dipole–dipole interactions and acid–base equilibrium. The presence of phenyl rings, secondary amino groups and alkyl linkers in the resulting material made it suitable for the separation of above-mentioned analytes by multimode retention mechanisms.
