Co-reporter:Xiudan Hou, Yong Guo, Xiaojing Liang, Xusheng Wang, Lei Wang, Licheng Wang, Xia Liu
Talanta 2016 Volume 153() pp:392-400
Publication Date(Web):1 June 2016
DOI:10.1016/j.talanta.2016.03.034
•NTf2−-based PILs-GO SPME fibers were prepared by on-fiber anion exchange.•NTf2−-based PILs exhibited more hydrophobic than Br−-based PILs.•We investigated the partition coefficients of analytes between different ILs-GO fibers and aqueous solution.•The proposed SPME fiber was successfully used to extract PAHs and PAEs in real samples.A class of novel, environmental friendly ionic liquids (ILs) were synthesized by on-fiber preparation strategy and modified on graphene oxide (GO)-coated stainless steel wire, which was used as a solid-phase microextraction (SPME) fiber for efficient enrichment of polycyclic aromatic hydrocarbons (PAHs) and phthalate esters (PAEs). Surface characteristic of the ILs and polymeric-ILs (PILs) fibers with the wave-structure were inspected by scanning electron microscope. The successfully synthesis of bis(trifluoromethanesulfonyl)imide (NTf2−)-based ILs were also characterized by energy dispersive spectrometer analysis. Through the chromatograms of the proposed two ILs (1-aminoethyl-3-methylimidazolium bromide (C2NH2MIm+Br−), C2NH2MIm+NTf2−) and two PILs (polymeric 1-vinyl-3-hexylimidazolium bromide (poly(VHIm+Br−)), poly(VHIm+NTf2−))-GO-coated fibers for the extraction of analytes, NTf2−-based PIL demonstrated higher extraction capacity for hydrophobic compounds than other as-prepared ILs. Analytical performances of the proposed fibers were investigated under the optimized extraction and desorption conditions coupled with gas chromatography (GC). Compared with the poly(VHIm+Br−)-GO fiber, the poly(VHIm+NTf2−)-GO SPME fiber brought wider linear ranges for analytes with correlation coefficient in the range of 0.9852–0.9989 and lower limits of detection ranging from 0.015–0.025 μg L−1. The obtained results indicated that the newly prepared PILs-GO coating was a feasible, selective and green microextraction medium, which could be suitable for extraction and determination of PAHs and PAEs in potatoes and food-wrap sample, respectively.Different ILs and PILs modified onto the GO-coated stainless steel wire were optimized and we selected the NTf2−-based PIL-GO SPME fiber to detect PAHs in potatoes and PAEs in food-wrap.
Co-reporter:Xiudan Hou, Licheng Wang, Xiaofen Tang, Chunming Xiong, Yong Guo and Xia Liu
Analyst 2015 vol. 140(Issue 19) pp:6727-6735
Publication Date(Web):18 Aug 2015
DOI:10.1039/C5AN01030F
A new β-cyclodextrin/graphene oxide hybrid material prepared via a chemical covalent interaction and layer-to-layer assembly was developed as a sorbent for the solid-phase microextraction of fragrance allergens. As a result of its ultra-large surface area, large delocalized π-electron system and abundant hydroxyls, the β-cyclodextrin/graphene oxide-coated fiber could be used to extract particular compounds via strong π–π interactions, van der Waals forces and hydrogen bonding interactions. β-Cyclodextrin with a hydrophobic interior cavity and hydrophilic peripheral face was conducive in extracting the fragrances with hydrophobic and hydrophilic groups. Under the optimized extraction and desorption conditions, the β-cyclodextrin/graphene oxide-coated fiber showed acceptable extraction efficiency for hydrophilic and hydrogen-bonding-donating alcohols. Compared with other methods based on different coating fibers, the proposed fiber obtained wide linear ranges for fragrances with correlation coefficients ranging from 0.9921 to 0.9970, and low limits of detection in the range of 0.050–0.150 μg L−1. The obtained results indicated that the newly developed fiber was a selective, feasible and cost-effective microextraction medium and could be successfully applied for the determination of several fragrances in personal products.
Co-reporter:Xiudan Hou, Sheng Tang, Yong Guo, Shujuan Liu, Jubai Li, Licheng Wang and Xia Liu
RSC Advances 2015 vol. 5(Issue 33) pp:26114-26114
Publication Date(Web):12 Mar 2015
DOI:10.1039/C5RA90025E
Correction for ‘Novel dextran/graphene oxide composite material as a sorbent for solid-phase microextraction of polar aromatic compounds’ by Xiudan Hou et al., RSC Adv., 2015, 5, 21720–21727.
Co-reporter:Xiudan Hou, Sheng Tang, Yong Guo, Shujuan Liu, Jubai Li, Licheng Wang and Xia Liu
RSC Advances 2015 vol. 5(Issue 28) pp:21720-21727
Publication Date(Web):18 Feb 2015
DOI:10.1039/C4RA15853A
A novel solid-phase microextraction (SPME) fiber for extraction of polar aromatic compounds was prepared by chemically bonding a dextran/graphene oxide (GO) composite material on stainless steel wire. Coupled with gas chromatography (GC), the fiber was used to extract phenols and halogenated aromatic compounds in aqueous samples. The analytical performances of the proposed fiber were evaluated under optimized extraction conditions. The wide linear ranges were 0.10–200 μg L−1, 0.20–200 μg L−1 for different target compounds; the detection limits ranged from 0.015 μg L−1 to 0.050 μg L−1; single-fiber repeatability and fiber-to-fiber reproducibility were in the range of 2.7–10.6% and 5.5–13.7%, respectively. The outstanding stability of the prepared fiber was demonstrated by its ability to sustain more than 100 times usage with relative standard deviations for extraction efficiency less than 13.7%. The dextran/GO-coated SPME fiber was applied to determine phenols and halogenated aromatics in two real water samples, and satisfactory results were obtained.
Co-reporter:Houmei Liu, Xiaojing Liang, Xusheng Wang, Yong Guo and Xia Liu
RSC Advances 2015 vol. 5(Issue 6) pp:4420-4427
Publication Date(Web):09 Dec 2014
DOI:10.1039/C4RA13331E
In this paper, a novel sorbent, poly(diallyldimethylammonium chloride) assembled graphene oxide coated silica (PDDA@GO@SiO2), was prepared and used as a sorbent for solid-phase extraction of cinnamic acid and its derivatives. The synthesized sorbent material was characterized by elemental analysis and field emission scanning electron microscopy, which confirmed the success of binding and assembling. The extraction properties of the resultant sorbent were evaluated by using cinnamic acid and its derivatives (caffeic acid, trans-4-hydroxycinnamic acid, isoferulic acid, 3,4-dimethoxycinnamic acid, cinnamic acid and 4-methylcinnamic acid) as the test analytes. Extraction efficiencies of PDDA@GO@SiO2 were apparently superior to those of PDDA@SiO2 and commercial C18 sorbents. Under the optimal conditions, good linearities with R2 ranging from 99.8% to 100% were obtained and the LODs and LOQs were found to be in the range of 0.5–2 μg L−1 and 3–5 μg L−1, respectively. The proposed method was successfully applied for the analysis of cinnamic acid in Gobi sherry and isoferulic acid in BuzhongYiqi pill.
Co-reporter:Xiudan Hou;Hui Yu;Yong Guo;Xiaojing Liang;Shuai Wang;Licheng Wang
Journal of Separation Science 2015 Volume 38( Issue 15) pp:2700-2707
Publication Date(Web):
DOI:10.1002/jssc.201401435
A new polyethylene glycol/graphene oxide composite material bonded on the surface of a stainless-steel wire was used for solid-phase microextraction. The layer-by-layer structure increased the adsorption sites of the novel fiber, which could facilitate the extraction of trace compounds. The polyethylene glycol/graphene oxide was characterized by Fourier transform infrared spectroscopy and elemental analysis, which verified that polyethylene glycol was successfully grafted onto the surface of graphene oxide. The performance of the polyethylene glycol/graphene oxide coated fiber was investigated for phenols and phthalate esters coupled with gas chromatography with flame ionization detection under the optimal extraction and desorption conditions, and the proposed method exhibited an excellent extraction capacity and high thermal stability. Wide linear ranges were obtained for the analytes with good correlation coefficients in the range of 0.9966–0.9994, and the detection limits of model compounds ranged from 0.003 to 0.025 μg/L. Furthermore, the as-prepared fiber was used to determine the model compounds in the water and soil samples and satisfactory results were obtained.
Co-reporter:Houmei Liu, Yong Guo, Xusheng Wang, Yikun Li, Xiaojing Liang and Xia Liu
Analytical Methods 2015 vol. 7(Issue 1) pp:135-142
Publication Date(Web):24 Oct 2014
DOI:10.1039/C4AY02172J
In this paper, a novel sorbent, double carboxyl silicane modified graphene oxide coated silica has been prepared and used as sorbent for solid-phase extraction of quarternary alkaloids. The synthesized sorbent material was characterized by elemental analysis and field emission scanning electron microscopy. The extraction properties of the developed sorbent were evaluated by four quarternary alkaloids: coptisine chloride, sanguinarine, berberine chloride and chelerythrine. Multiple interactions, i.e., electrostatic, hydrogen bonding and dipole–dipole interactions, take place during the extraction. After the optimization of conditions, several parameters, such as volume of sample loading, pH of sample, pH of eluent and sample loading velocity, were set up. Under the optimal conditions, good linearities with R2 ranging from 0.9990 to 0.9995 were obtained for the four compounds. The LODs were found to be in the range of 1–2 μg L−1, and the LOQs were found to be in the range of 2–5 μg L−1. The recoveries of the four quarternary alkaloids spiked with 5 μg L−1 in human urine samples ranged from 89.1% to 110.6% with RSDs in the range of 2.6–10.4%. The results showed that the new sorbent has excellent extraction capacity for the tested quarternary alkaloids.
Co-reporter:Sheng Tang, Yong Guo, Xiaojing Liang, Falin Wei, Limin Yang, Shujuan Liu, Xia Liu and Shengxiang Jiang
Analytical Methods 2015 vol. 7(Issue 11) pp:4750-4756
Publication Date(Web):01 May 2015
DOI:10.1039/C5AY00611B
A novel mixed-mode monolithic stationary phase based on bonding of 4,5-imidazoledicarboxy acid to the surface of an organic-silica hybrid monolith was prepared and characterized. Satisfactory characteristics in terms of mechanical stability, permeability and reproducibility of the resultant monolithic column were achieved. A typical per aqueous chromatographic behavior was observed in water-rich mobile phases. The resultant monolithic column was applied for the efficient resolution of various polar and hydrophilic compounds under per aqueous or reversed-phase chromatographic conditions, which successfully demonstrated its suitability for the analysis of these polar compounds in highly aqueous mobile phases. The highest column efficiency obtained for the amines was 149000 N m−1. The experimental results showed that the mixed-mode mechanism of hydrophobic and ion-exchange interactions was involved in the separation under the given conditions. The successful applications suggested that the mixed-mode organic-silica hybrid monolithic column could offer a wide range of retention behaviors and flexible selectivities toward polar compounds, achieving various target separations.
Co-reporter:Houmei Liu, Yong Guo, Xusheng Wang, Xiaojing Liang and Xia Liu
Analytical Methods 2015 vol. 7(Issue 8) pp:3486-3492
Publication Date(Web):17 Mar 2015
DOI:10.1039/C5AY00271K
In this paper, a novel sorbent, nano-Al2O3 coated mesoporous silica (Al2O3/SiO2), was prepared and used as a sorbent for solid-phase extraction of flavonoids. The synthesized sorbent material was characterized by X-ray photoelectron spectroscopy, energy dispersive spectroscopy and inductively coupled plasma emission spectrometry. The extraction properties of the resultant sorbent were evaluated by using four flavonoids (myricetin, quercetin, luteolin and kaempferol) as the test analytes. The extraction efficiencies of Al2O3/SiO2 were apparently superior to those of commercial C18 sorbents. Under optimal conditions, good linearities with R2 ranging from 98.8% to 99.8% were obtained and the LODs and LOQs were found to be in the range of 0.5–1 μg L−1 and 2.5–3 μg L−1, respectively. The proposed method was successfully applied for the real sample analysis of wild honey and red grape juice.
Co-reporter:Houmei Liu, Yong Guo, Xusheng Wang, Xiaojing Liang, Xia Liu and Shengxiang Jiang
RSC Advances 2014 vol. 4(Issue 34) pp:17541-17548
Publication Date(Web):02 Apr 2014
DOI:10.1039/C4RA01408A
Hydrophilic interaction liquid chromatography has been widely used for separating hydrophilic compounds and the development of new stationary phases for HILIC is significant. In this study, fullerene oxide was successfully assembled onto silica microspheres to form a FO-modified silica stationary phase. The synthesized material was characterized by elemental analysis, transmission electron microscopy, Raman spectroscopy and contact angle analysis. The chromatographic properties of the stationary phase were investigated in HILIC mode for analysis of nucleosides, nucleobases, water soluble vitamins, amino acids and saccharides. Good separations of these compounds were achieved on the resulting column. Compared with the aminopropylated silica column, FO/SiO2 column exhibited better separation efficiency. This study also investigated the effect of various experimental factors on the retention of the polar stationary phases, such as acetonitrile content and salt concentration in the mobile phase.
Co-reporter:Houmei Liu, Yong Guo, Xusheng Wang, Xiaojing Liang and Xia Liu
RSC Advances 2014 vol. 4(Issue 70) pp:37381-37388
Publication Date(Web):14 Aug 2014
DOI:10.1039/C4RA03432E
In this study, an amino-terminated ionic liquid modified graphene oxide coated silica composite stationary phase (IL@GO@SiO2) has been synthesized and applied for the separation of B vitamins, amino acids and aromatic acids in hydrophilic interaction chromatography (HILIC) mode. The synthesized novel material was characterized by elemental analysis, field emission scanning electron microscopy and infrared spectroscopy. The chromatographic properties of the IL@GO@ SiO2 phase were compared with those of the pure silica phase, amino-terminated ionic liquid modified silica phase, and graphene oxide modified silica phase. The results show that IL@GO@SiO2 exhibits the best separation efficiency compared to the other three phases, which is ascribed to the existence of the multiple interactions, i.e., electrostatic interactions, π–π interactions and dipole–dipole interactions between the resulting stationary phase and the analytes. The differences between the four stationary phases illustrate that the combination of IL and GO plays an important role in improving the separation efficiency.
Co-reporter:Jing Jia, Shujuan Liu, Yong Guo, Shuai Wang and Xia Liu
Analytical Methods 2014 vol. 6(Issue 19) pp:7875-7882
Publication Date(Web):04 Jul 2014
DOI:10.1039/C4AY00504J
In this work, a nanoporous array anodic titanium was selected as a fiber substrate because of its high surface-to-volume ratio, easy preparation, mechanical stability, and rich titanol groups on its surface that can anchor other active groups. Then, a polymerizable ionic liquid monomer pair, (1-vinyl-3-hexadecylimidzolium)-(p-styrenesulfonate) ([C16VIm]+SS−), was synthesized and used for the chemical modification of the mercaptopropyl-functionalized nanoporous anodic titania support using a surface radical chain-transfer addition. A homogeneous and porous coating with a thickness of about 7 μm was achieved. The main advantage of this copolymerization method over the conventional single-ion polymerization is its high stability under harsh conditions, like high temperatures, as well as acidic, alkaline and high ionic strength solutions. Combined with gas chromatography-a flame ionization detection (GC-FID), the poly[C16VIm]+SS− was used as a sorbent material for the direct immersion SPME of four types of compounds, including polycyclic aromatic hydrocarbons, hydrophobic phenols, non-volatile phthalate esters and parabens, in an aqueous solution. The analytical performance of the proposed method was investigated under the optimum extraction conditions (content of NaCl, 20% (w/v); extraction temperature, 70 °C; and extraction time, 55 min). Calibration ranges were 0.1–400 μg L−1 for four hydrophobic phenols, anthracene (Ant) and fluoranthene (Flt), 0.15–600 μg L−1 for dibutyl phthalate (DBP) and di-(2-ethyl-hexyl) phthalate (DEHP), and 0.5–2000 μg L−1 for ethylparaben (EPN) and propylparaben (PPN). The as-established method showed good linearity with good correlation coefficients (R = 0.993–0.999) and low detection limits in the range of 0.003 to 0.156 ng mL−1 (S/N = 3). In addition, the poly[C16VIm]+SS−-SPME fiber showed good precision (3.2–13.5%) and repeatability between fiber and fiber (9.1–19.6%). Finally, soil extract sample were analyzed and satisfactory results were obtained.
Co-reporter:Zheng Wei, Haixia Ren, Shuai Wang, Hongdeng Qiu, Xia Liu, Shengxiang Jiang
Materials Letters 2013 Volume 105() pp:144-147
Publication Date(Web):15 August 2013
DOI:10.1016/j.matlet.2013.04.078
•We prepared uniform micron-sized mesoporous carbon spheres via a facile method.•The average size can be tuned while remaining the uniformity.•The spheres are special for their morphology and bimodal porous structure.•The spheres can be used as a chromatographic sorbent.Well dispersed uniform porous carbon microspheres were obtained through facile polymerization-induced colloid aggregation and carbonization process. The effect of the preparatory conditions on the properties of the prepared samples has been analyzed. The average size of the microspheres could be tuned while maintaining the uniformity of the spheres. Detailed characterization of the samples reveals that the carbon microspheres prepared in this study have large surface area signified by the presence of both mesopores and micropores. The properties make these spheres ideal for use as a chromatographic adsorbent. The chromatographic column packed by the prepared porous carbon microspheres with average diameter of 5.2 µm has shown a great separation performance for hydrophilic compound mixtures.
Co-reporter:Jing Jia, Xiaojing Liang, Licheng Wang, Yong Guo, Xia Liu, Shengxiang Jiang
Journal of Chromatography A 2013 1320() pp: 1-9
Publication Date(Web):
DOI:10.1016/j.chroma.2013.10.042
Co-reporter:Haifeng Han, Qing Wang, Xia Liu, Shengxiang Jiang
Journal of Chromatography A 2012 Volume 1246() pp:9-14
Publication Date(Web):13 July 2012
DOI:10.1016/j.chroma.2011.12.029
A polymeric ionic liquid (PIL) modified hybrid monolithic column for CEC was synthesized on the basis of mercaptopropy-functionalized (MP-silica) hybrid monolithic column which was prepared by the in situ co-condensation of tetramethoxysilane and 3-mercaptopropyltrimethoxysilane via a sol–gel process. The PIL modified (PImC8-silica) hybrid monolithic column, which was characterized by FT-IR and X-ray Photoelectron spectroscopy (XPS), generated a strong reversed and relatively stable EOF in a wide range of pH (3.0–8.0). The PImC8-silica hybrid monolithic column was evaluated by the separation of three aromatic hydrocarbons (AHs), four alkylbenzenes and five phenols, respectively, with phosphate buffers containing different ratios of acetonitrile as mobile phase. Reproducibilities of the column were also investigated by measuring RSDs of the migration time for AHs. RSDs of run-to-run (n = 5), day-to-day (n = 3) and column-to-column (n = 3) were in the range of 0.26–0.87%, 0.90–3.2% and 1.5–5.7%, respectively.Highlights► In this study polymeric ionic liquid is applied to monolithic column. ► The columns are characterized by FT-IR, SEM, XPS. ► The EOF is reversed strongly in a wide range of pH. ► Hydrophobic effect and π–π interactions are found in the separation.
Co-reporter:Min Sun, Juanjuan Feng, Shujuan Liu, Chunming Xiong, Xia Liu, Shengxiang Jiang
Journal of Chromatography A 2011 Volume 1218(Issue 24) pp:3743-3749
Publication Date(Web):17 June 2011
DOI:10.1016/j.chroma.2011.04.036
A novel multi-interaction stationary phase based on 4,4′-dipyridine modified silica was synthesized and characterized, by infrared spectra, X-ray photoelectron spectroscopy and elemental analysis. Mechanism involved in the chromatographic separation is the multi-interaction including π–π, hydrophobic, hydrogen-bonding, electrostatic and anion-exchange interactions. Based on these interactions, polycyclic aromatic hydrocarbons and phenols were successfully separated respectively in reversed-phase chromatography; inorganic and organic anions were also separated individually in anion-exchange chromatography by using the same column. Furthermore, the simultaneous separation of neutral organics, inorganic and organic anions was obtained on this stationary phase with the appropriate mobile phase. Therefore, such stationary phase has the characteristics of multi-interaction mechanism and multi-modal separation, and has potential application on complex samples.
Co-reporter:Haifeng Han;Jing Li;Xusheng Wang;Shengxiang Jiang
Journal of Separation Science 2011 Volume 34( Issue 16-17) pp:2323-2328
Publication Date(Web):
DOI:10.1002/jssc.201100050
Abstract
An ionic liquid (IL) was introduced into the organic-silica hybrid monolithic column as the stationary phase for capillary electrochromatography (CEC). The monolithic silica matrix containing chloropropyl functional group was prepared by the in situ co-condensation of tetramethoxysilane and (3-chloropropyl)-trimethoxysilane via a sol–gel process and chemical modification with N-methylimidazole. The electroosmotic flow of the IL-modified hybrid monolithic column was reversed at acidic pH and the morphology of the column was characterized by scanning electron microscope. Four aromatic hydrocarbons were completely separated with 40% acetonitrile phosphate buffer as the mobile phase and seven inorganic ions were efficiently separated with the phosphate buffer on the column in CEC. Reproducibilities of migration time for four aromatic hydrocarbons (benzene, naphthalene, anthracene, chrysene) were acceptable on IL-modified hybrid monolithic columns. Relative standard deviations of run-to-run (n=5), peak area-to-peak area (n=5), day-to-day (n=3) and column-to-column (n=3) were in the range of 0.72–0.88, 1.47–5.40, 2.44–4.99 and 3.01–8.11%, respectively.
Co-reporter:Zheng Wei;Licheng Wang;Jing Li;Shengxiang Jiang
Chromatographia 2011 Volume 73( Issue 1-2) pp:5-16
Publication Date(Web):2011 January
DOI:10.1007/s10337-010-1834-0
Cyanobiphenyl-mesogened liquid crystalline polymer is bonded on silica by surface-initiated atom transfer radical polymerization and is used as the stationary phase for liquid chromatography. Various instrumental analyses such as elemental analysis, X-ray photoelectron spectroscopy and differential scanning calorimetry were used for its characterization. The stationary phase exhibits multiple characteristics of low hydrophobicity, low hydrophobic selectivity, polarity recognition and shape selectivity in the separation of polyaromatic hydrocarbons and polar neural aromatic compounds. Temperature and mobile phase composition were confirmed to have effects on the chromatographic behavior. Isomers of polyaromatic hydrocarbons and carotenes are well separated on the stationary phase.
Co-reporter:Hongdeng Qiu;Min Sun;Jingang Niu;Shengxiang Jiang
Chromatographia 2010 Volume 71( Issue 5-6) pp:355-359
Publication Date(Web):2010 March
DOI:10.1365/s10337-009-1442-z
A facile strong cation-exchange stationary phase based on propylsulfonic acid functionalized silica was prepared through the oxidation in situ of 3-mercaptopropyl silica and characterized by elemental analysis and X-ray photoelectron spectroscopy. The phase was used to separate monovalent and divalent inorganic cations with strong acid as mobile phase. Simultaneous separation of alkali metals and alkaline earth metals was examined and the cations sodium, magnesium and calcium in tap water were determined.
Co-reporter:Min Sun, Hongdeng Qiu, Licheng Wang, Xia Liu, Shengxiang Jiang
Journal of Chromatography A 2009 Volume 1216(Issue 18) pp:3904-3909
Publication Date(Web):1 May 2009
DOI:10.1016/j.chroma.2009.02.089
A new specific stationary phase based on poly(1-allylimidazole)-grafted silica has been synthesized and characterized, by infrared spectra, elemental analysis, thermogravimetric analysis and X-ray photoelectron spectroscopy. The results of test showed that poly(1-allylimidazole) can effectively mask the residual silanol groups and reduce the adverse effect of residual silanol. Using this stationary phase, phenol compounds, aniline compounds, and polycyclic aromatic hydrocarbons were successfully separated with symmetric peak shapes in the reversed-phase chromatography. Inorganic anions (IO3−, BrO3−, Br−, NO3−, I−, SCN−) were also separated completely in the anion-exchange chromatography using sodium chloride solution as the mobile phase. The effects of pH and the concentration of eluent on the separation of inorganic anions were studied. The separation mechanism appears to involve the mixed interactions of hydrogen bonding, hydrophobic, π–π, electrostatic, and anion-exchange interactions.
Co-reporter:Hongdeng Qiu, Licheng Wang, Xia Liu and Shengxiang Jiang
Analyst 2009 vol. 134(Issue 3) pp:460-465
Publication Date(Web):27 Nov 2008
DOI:10.1039/B809125K
Ionic liquids (ILs) have been used in various regions of chemistry. Ionic liquids have designability, thus giving us the ability to manipulate the structure (with respect to the organic cation, inorganic anion and the length of the side chain attached to the organic cation) and consequently their properties. In this manuscript, two new different chromatographic stationary phases based on different ionic liquid-modified silica particles were prepared through surface radical chain-transfer reaction and characterized with elemental analysis, Raman spectroscopy and X-ray photoelectron spectroscopy. 1-Allyl-3-butylimidazolium ionic liquid-modified silica particles can be used as a strong anion-exchange stationary phase. 1-Allyl-3-(butyl-4-sulfonate)imidazolium ionic liquid-modified silica particles were used for the first time as the covalently bonded charge-balanced zwitterionic stationary phase in electrostatic ion chromatography for the simultaneous separation of inorganic anions and cations with pure water as the mobile phase.
Co-reporter:Hongdeng Qiu;Qiong Jiang;Shengxiang Jiang
Chromatographia 2008 Volume 68( Issue 3-4) pp:167-171
Publication Date(Web):2008 August
DOI:10.1365/s10337-008-0683-6
Two new silica-based long-chain alkylimidazolium stationary phases were prepared and characterized for their use in high-performance liquid chromatography. The stationary phases were both prepared by the reaction of chloropropyl silica with long-chain alkylimidazoles and were used to separate common inorganic anions. Hydrophobic interactions were also studied by the comparison of differential retention of various organic compounds. The alkyl chain length did not show an impact on the anion-exchange process but affected the hydrophobic interaction of the stationary phases.
Co-reporter:Jian-Zhong Lu;Jian-Ying Liang;Choiwan Lau;Ping Yang
Luminescence 2007 Volume 22(Issue 5) pp:473-479
Publication Date(Web):11 JUL 2007
DOI:10.1002/bio.987
The reactions of acetaldehyde with O atoms in the cages of large-pore zeolites have been discovered to result in light emission. The luminescence characteristics of acetaldehyde vapours passing through the surface of chosen zeolites were studied using a cataluminescence-based detection system. To demonstrate the feasibility of the method, the detection of acetaldehyde using catalysts was studied systematically and a linear response of 0.06–31.2 µg/mL acetaldehyde vapour was obtained. Methanol, ethanol, isopropanol, methylbenzene, chloroform, dichlormethane and acetonitrile did not interfere with the determination of acetaldehyde. Acetaldehyde vapour could also be distinguished from some homologous series such as formaldehyde, cinnamaldehyde, glutaraldehyde and benzaldehyde on this catalyst, possibly due to the stereoselectivity of the zeolite and its specific reaction mechanism. Moreover, acetaldehyde was quantified without detectable interference from formaldehyde in four artificial samples. Thus, this kind of cataluminescence-based sensor could be potentially extended to the analysis of volatile organic compounds in air, and the simple and portable properties of cataluminescence-based sensors could also make them beneficial in many areas of analytical science. Copyright © 2007 John Wiley & Sons, Ltd.
Co-reporter:
Analytical Methods (2009-Present) 2014 - vol. 6(Issue 19) pp:
Publication Date(Web):
DOI:10.1039/C4AY00504J
In this work, a nanoporous array anodic titanium was selected as a fiber substrate because of its high surface-to-volume ratio, easy preparation, mechanical stability, and rich titanol groups on its surface that can anchor other active groups. Then, a polymerizable ionic liquid monomer pair, (1-vinyl-3-hexadecylimidzolium)-(p-styrenesulfonate) ([C16VIm]+SS−), was synthesized and used for the chemical modification of the mercaptopropyl-functionalized nanoporous anodic titania support using a surface radical chain-transfer addition. A homogeneous and porous coating with a thickness of about 7 μm was achieved. The main advantage of this copolymerization method over the conventional single-ion polymerization is its high stability under harsh conditions, like high temperatures, as well as acidic, alkaline and high ionic strength solutions. Combined with gas chromatography-a flame ionization detection (GC-FID), the poly[C16VIm]+SS− was used as a sorbent material for the direct immersion SPME of four types of compounds, including polycyclic aromatic hydrocarbons, hydrophobic phenols, non-volatile phthalate esters and parabens, in an aqueous solution. The analytical performance of the proposed method was investigated under the optimum extraction conditions (content of NaCl, 20% (w/v); extraction temperature, 70 °C; and extraction time, 55 min). Calibration ranges were 0.1–400 μg L−1 for four hydrophobic phenols, anthracene (Ant) and fluoranthene (Flt), 0.15–600 μg L−1 for dibutyl phthalate (DBP) and di-(2-ethyl-hexyl) phthalate (DEHP), and 0.5–2000 μg L−1 for ethylparaben (EPN) and propylparaben (PPN). The as-established method showed good linearity with good correlation coefficients (R = 0.993–0.999) and low detection limits in the range of 0.003 to 0.156 ng mL−1 (S/N = 3). In addition, the poly[C16VIm]+SS−-SPME fiber showed good precision (3.2–13.5%) and repeatability between fiber and fiber (9.1–19.6%). Finally, soil extract sample were analyzed and satisfactory results were obtained.
![1,2-dimethoxy-12-methyl[1,3]benzodioxolo[5,6-c]phenanthridinium](http://img.cochemist.com/ccimg/34400/34316-15-9.png)
![1,2-dimethoxy-12-methyl[1,3]benzodioxolo[5,6-c]phenanthridinium](http://img.cochemist.com/ccimg/34400/34316-15-9_b.png)
![Benzenemethanol, a-[1-(dimethylamino)ethyl]-](http://img.cochemist.com/ccimg/17700/17605-71-9.png)
![Benzenemethanol, a-[1-(dimethylamino)ethyl]-](http://img.cochemist.com/ccimg/17700/17605-71-9_b.png)
