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1.
Environ Sci Pollut Res Int ; 31(11): 16401-16412, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38311685

ABSTRACT

Graphene (GR) is a new type of carbon-based material that combines many excellent properties. In order to give full play to the excellent properties of graphene and expand its application scope, this study used ionic liquid SbF6 to modify it and successfully prepared ionic liquid modified graphene composites (H/GR), and studied its adsorption mechanism of arsenic in aqueous solution. By investigating the effects of reaction temperature, reaction time, pH, adsorbent (H/GR) dosage, and humic acid concentration on the removal rate of arsenic in aqueous solution, the experimental results showed that when the reaction temperature was 30 °C, reaction time was 1 h, pH was 6, H/GR dosage was 0.1g·L-1, and humic acid (HA) concentration was 10 mg·L-1, the best arsenic removal effect was achieved with a maximum. The removal rate was 99.4%. The equilibrium adsorption capacity was well modeled by the Langmuir, Freundlich, and Tenkin models at 30 °C. The Langmuir adsorption isotherm was the most consistent, with a calculated maximum value of 137.95 mg·g-1, which is higher than most adsorbents in the field. In addition, it was determined that the graphene surface was indeed immobilized with the ionic liquid [Hmim]SbF6 by SEM mapping and EDS energy spectroscopy observation, and the adsorption isotherms and pore size distribution maps of graphene before and after the loading of the ionic liquid were analyzed by BET, which further confirmed a significant increase in the microporosity and porosity of the modified H/GR, and furthermore, it was demonstrated that the arsenic ions are chemically bonded with and indeed adsorbed on the surface of the H/GR by FT-IR and XPS characterization analyses. The results of all experimental data studies indicate that the main mechanism of As(V) removal from water by H/GR is due to electrostatic adsorption, ion exchange, and complexation between the modified graphene itself and the ionic liquid [Hmim]SbF6 itself.


Subject(s)
Arsenic , Graphite , Ionic Liquids , Water Pollutants, Chemical , Arsenic/analysis , Graphite/chemistry , Ionic Liquids/analysis , Adsorption , Spectroscopy, Fourier Transform Infrared , Humic Substances/analysis , Water , Water Pollutants, Chemical/analysis , Hydrogen-Ion Concentration , Kinetics
2.
Anal Biochem ; 688: 115464, 2024 May.
Article in English | MEDLINE | ID: mdl-38244752

ABSTRACT

This study describes the development of a highly sensitive amperometric biosensor for the analysis of phenolic compounds such as catechol. The biosensor architecture is based on the immobilization of tyrosinase (Tyr) on a screen-printed carbon electrode (SPE) modified with nanodiamond particles (ND), 1-butyl-3-methylimidazolium hexafluorophosphate (IL) and poly-l-lysine (PLL). Surface morphologies of the electrodes during the modification process were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to investigate the electrochemical characteristics of the modified electrodes. Owing to the synergistic effect of the modification materials, the Tyr/PLL/ND-IL/SPE exhibited high sensitivity (328.2 µA mM-1) towards catechol with a wide linear range (5.0 × 10-8 - 1.2 × 10-5 M) and low detection limit (1.1 × 10-8 M). Furthermore, the method demonstrated good reproducibility and stability. The amperometric response of the biosensor towards other phenolic compounds such as bisphenol A, phenol, p-nitrophenol, m-cresol, p-cresol and o-cresol was also investigated. The analytical applicability of the biosensor was tested by the analysis of catechol in tap water. The results of the tap water analysis showed that the Tyr/PLL/ND-IL/SPE can be used as a practical and effective method for catechol determination.


Subject(s)
Biosensing Techniques , Ionic Liquids , Nanodiamonds , Ionic Liquids/analysis , Polylysine , Reproducibility of Results , Phenols/analysis , Catechols/analysis , Catechols/chemistry , Monophenol Monooxygenase/chemistry , Carbon/chemistry , Water , Biosensing Techniques/methods , Electrodes , Electrochemical Techniques/methods
3.
J Dairy Sci ; 106(9): 5916-5929, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37500441

ABSTRACT

Two PPG1000 based temperature-sensitive magnetic ionic liquid were synthesized and characterized. The temperature-sensitive magnetic ionic liquid aqueous biphasic system combined with HPLC was applied for the continuous enrichment and trace analysis of tetracycline antibiotics (TC) in bovine milk for the first time. High enrichment factors were achieved and the detection was highly sensitive. The trace analysis of TC was rapid, free of organic solvent, recyclable and magnetically assisted for phase separation. Under optimum conditions, wide linear ranges of 0.25-300 ng/mL for all TC, high enrichment factors of 217.7-231.4, good precisions with relative standard deviation in the range of 0.74-3.97%, very low limits of detection of 0.031-0.067 ng/mL, limits of quantification of 0.103-0.223 ng/mL, and good recoveries of 94.28-99.76% were acquired for the proposed analytical method. Real milk analysis was satisfactory. This developed analytical method is showing great potential for trace analysis of targeted analytes in foods and drinks.


Subject(s)
Ionic Liquids , Animals , Ionic Liquids/analysis , Ionic Liquids/chemistry , Chromatography, High Pressure Liquid/methods , Chromatography, High Pressure Liquid/veterinary , Milk/chemistry , Tetracyclines/analysis , Water/analysis , Anti-Bacterial Agents/analysis
4.
J Chromatogr A ; 1689: 463745, 2023 Jan 25.
Article in English | MEDLINE | ID: mdl-36586287

ABSTRACT

In this work, Friedel-Crafts alkylation was successfully applied to prepare a magnetic ionic liquid hypercrosslinked polymer composite (Fe3O4@IL-HCP), which was subsequently employed as magnetic solid-phase extraction (MSPE) adsorbent for the isolation and enrichment of trace non-steroidal anti-inflammatory drugs (NSAIDs). The developed composite was comprehensively characterized using various techniques, with the results indicating that it possessed high saturation magnetization (39.44 em g - 1), large specific surface area (175 m2g - 1), and high adsorption capacity for NSAIDs. The adsorption behavior and mechanisms were also investigated in detail. NSAIDs were adsorbed onto the Fe3O4@IL-HCP sorbent via a heterogeneous multilayer process consisting of hydrogen bonding and π-π and electrostatic interactions. Additionally, the composite's large surface area and multiple active sites enabled extraction equilibrium within 6 min. By coupling with high performance liquid chromatography (HPLC), the developed MSPE/HPLC method was applied for the determination of selected NSAIDs in water and urine samples. The developed method displayed wide linear ranges, low limits of detection (0.12-0.30 ng mL-1 and 0.15-1.5 ng mL-1 in water and urine samples, respectively), sufficient recoveries (92.8-109%), and good precision (relative standard deviations ≤ 4.6%). Thus, the findings of this work provide an appealing alternative for the extraction and determination of trace NSAIDs in environmental water and biological samples.


Subject(s)
Ionic Liquids , Water , Water/chemistry , Ionic Liquids/analysis , Polymers/chemistry , Anti-Inflammatory Agents, Non-Steroidal/analysis , Solid Phase Extraction/methods , Adsorption , Magnetic Phenomena , Chromatography, High Pressure Liquid , Limit of Detection
5.
Eur J Mass Spectrom (Chichester) ; 28(1-2): 25-34, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35746850

ABSTRACT

A rapid and sensitive analytical method was developed to quantitatively determine organic acids (OAs) from fish feed samples extracted by ion-pair (IP) solvent extraction, followed by in-situ butylation and gas chromatography-mass spectrometric (GC-MS) analysis. The extraction of OAs was carried out with acetonitrile containing 10 mM tetrabutylammonium hydroxide (TBAH), and the analytes were derivatized to their butyl esters in the injection port of the GC-MS system. The developed method was validated in the range of 1-5000 ng/g, with recoveries ranging from 93-117%. The limit of detection (LOD) and limit of quantification (LOQ) of the method was 1-5 ng/g and 2-10 ng/g, respectively, yielding good linearity (R2 > 0.9990) and precision with a relative standard deviation less than 10%. The proposed method was successfully applied to analyze OAs in sinking and floating fish feed samples. The analyzed samples showed the presence of benzoic, succinic, fumaric, glutaric, adipic, and phthalic acids in sinking feed samples; and benzoic, succinic, adipic, phthalic acids in floating feed samples, respectively.


Subject(s)
Ionic Liquids , Phthalic Acids , Animals , Gas Chromatography-Mass Spectrometry/methods , Ionic Liquids/analysis , Limit of Detection , Phthalic Acids/analysis
6.
J Sep Sci ; 45(14): 2621-2631, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35526264

ABSTRACT

Recently, pharmaceuticals and personal care products in the water environment exhibited potential risks to both human and aquatic organisms. In order to improve the sensitivity and accuracy of pharmaceutical detection, the polyimidazolyl acetate ionic liquid was synthesized by Radziszewski reaction and coated on cellulose filter papers as a thin-film extraction phase for extraction of non-steroidal anti-inflammatory drugs from water. The attenuated total reflection-infrared spectrometry, thermogravimetric analysis, and scanning electron microscope analyses demonstrated that the polyimidazolyl acetate ionic liquid was successfully prepared and attached to the surface of the cellulose filter paper through chemical bonding. The adsorption capacity of the homemade thin-film extraction material for the four non-steroidal anti-inflammatory drugs was greater than 8898 ng/cm2 under the optimum conditions, and the desorption rate was over 90%. Then, a paper-based thin-film extraction phase-high-performance liquid chromatography-tandem mass spectrometry method was established for the extraction of non-steroidal anti-inflammatory drugs in water. This method provided limits of detection and limits of quantification were in the range of 0.02-0.15 and 0.17-0.50 µg/L, respectively. Hence, the obtained thin-film extraction phase showed excellent recovery and reproducibility for the target non-steroidal anti-inflammatory drugs with carboxyl groups from water.


Subject(s)
Ionic Liquids , Water Pollutants, Chemical , Acetates , Anti-Inflammatory Agents, Non-Steroidal/analysis , Cellulose , Chromatography, High Pressure Liquid , Humans , Ionic Liquids/analysis , Limit of Detection , Reproducibility of Results , Solid Phase Extraction/methods , Water/chemistry , Water Pollutants, Chemical/analysis
7.
Forensic Sci Int ; 334: 111244, 2022 May.
Article in English | MEDLINE | ID: mdl-35395521

ABSTRACT

Estimates suggest billions of dollars are lost annually in the US due to fuel tax fraud. One method of fuel fraud is called "cocktailing" and involves blending products that are non-taxed, lower value, taxed at a lower rate, or unwanted/less-refined petroleum to diesel fuels. The goal of this study was to investigate compound specific isotope analysis (CSIA) using isotope ratio mass spectrometry (IRMS) for small aromatics contained in diesel fuel to determine whether this approach could be used to identify cocktailing and potentially fingerprint possible sources. However, the high chemical complexity of diesel fuels complicates CSIA owing to the need to fully separate individual compounds for effective isotope analysis. Therefore, different methods were investigated to selectively isolate aromatics for CSIA and evaluate these methods for isotopic fractionation. Analyses indicate that there is enough variability in isotopic ratios (δ2H and δ13C) between toluene samples obtained from different sources to use CSIA to differentiate/identify the origin of potential fuel adulterants. Three isolation methods were identified that provided sufficiently pure aromatic fractions for CSIA: selective solvent extraction, ionic liquid coated solid phase microextraction (SPME), and a combination of the two. However, due to the labor-intensive nature of selective solvent extraction, ionic liquid coated SPME represents the best method to quickly isolate aromatics from diesel fuel, without sacrificing selectivity or sensitivity. All methods tested can result in isotopic fractionation, but this can be compensated for by applying a correction factor. Furthermore, the chemical composition of a sample appeared to be important in the degree to which fractionation occurred during isolation. While the tested approaches for aromatic extraction from diesel showed promise, additional studies are required to refine and validate the methods prior to routine use in fuel cocktailing investigations.


Subject(s)
Gasoline , Ionic Liquids , Carbon Isotopes/analysis , Gas Chromatography-Mass Spectrometry/methods , Gasoline/analysis , Ionic Liquids/analysis , Isotopes/analysis , Solid Phase Microextraction
8.
Anal Bioanal Chem ; 414(1): 413-423, 2022 Jan.
Article in English | MEDLINE | ID: mdl-33763748

ABSTRACT

This paper describes the synthesis, characterization, and use of ionic liquids supported on silica, functionalized with graphene oxide through covalent bonding (ILz/Si@GO), as sorbents for microextraction by packed sorbent (MEPS). Seven selected pesticides (diazinon, heptachlor, aldrin, endrin, dieldrin, endosulfan, and methoxychlor), used for the prevention of pests in coffee crops, and endosulfan sulfate-an endosulfan metabolite-were selected for this study as model compounds for evaluating the sorbent performance of the synthesized materials in the MEPS device. The cycles of each of the stages were previously optimized through univariate experiments to carry out the extraction. The ILz/Si@GO phase was compared to other sorbents used in MEPS (GO, DVB-MMA, C4/SiO2, C8/SiO2, ILz/SiO2, and bare silica) and also with graphene functionalized through other methodologies, where ILz/Si@GO showed the best results. The material was characterized using a range of techniques. The selectivity of the sorbent material and its adsorption capacity were evaluated by gas chromatography coupled with tandem mass spectrometry. The precision and accuracy of the method showed a relative standard deviation lower than 10% and recoveries from 35 to 97%. Finally, the proposed method was employed for the determination of pesticide residues in coffee samples.


Subject(s)
Graphite , Ionic Liquids , Pesticides , Coffee , Gas Chromatography-Mass Spectrometry , Graphite/chemistry , Ionic Liquids/analysis , Limit of Detection , Pesticides/analysis , Silicon Dioxide/chemistry , Solid Phase Microextraction/methods
9.
J Chromatogr A ; 1621: 461084, 2020 Jun 21.
Article in English | MEDLINE | ID: mdl-32303345

ABSTRACT

This work presents a new triptycene-based dicationic guanidinium ionic liquid (TPG) as the stationary phase for gas chromatography (GC). To our knowledge, this is the first example of employing a dicationic guanidinium ionic liquid (GIL) for chromatographic analyses. As a result, the TPG column exhibited moderate polarity and column efficiency of 3840 plates/m and 3120 plates/m measured by naphthalene and 1-octanol at 120 °C, respectively. Particularly, the TPG column exhibited distinctly advantageous performance for the challenging Grob test mixture and the isomer mixture of phenols and anilines over the monocationic GIL and its counterpart with dicationic immidazolium units (TP-2IL). Also, it showed higher selectivity towards the isomers of alkanes, alcohols, diethylbenzenes, bromotoluenes, bromonitrobenzenes than the commercial DB-35MS column. Moreover, the TPG column achieved improved thermal stability over the GIL column and excellent repeatability with the RSD values of 0.01-0.05% for run-to-run, 0.11-0.24% for day-to-day and 2.4-4.1% for column-to-column. Its application to GC-MS analysis of the essential oil of Mentha haplocalyx proved its good potential for analysis of complex samples.


Subject(s)
Anthracenes/chemistry , Guanidine/chemistry , Ionic Liquids/chemistry , Alkanes/chemistry , Aniline Compounds/chemistry , Gas Chromatography-Mass Spectrometry , Ionic Liquids/analysis , Isomerism , Mentha/chemistry , Oils, Volatile/analysis , Phenols/chemistry , Reproducibility of Results , Solvents , Temperature
10.
Chemosphere ; 249: 126125, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32058133

ABSTRACT

The application of chemical dispersants in marine oil spill remediation is comprehensively reported across the globe. But, the augmented toxicity and poor biodegradability of reported chemical dispersants have created necessity for their replacement with the bio-based green dispersants. Therefore, in the present study, we have synthesized five ionic liquids (ILs) namely 1-butyl-3-methylimidazolium lauroylsarcosinate, 1,1'-(1,4-butanediyl)bis(1-H-pyrrolidinium) dodecylbenzenesulfonate, tetrabutylammonium citrate, tetrabutylammonium polyphosphate and tetrabutylammonium ethoxylate oleyl ether glycolate, and formulated a water based ILs dispersant combining the synthesized ILs at specified compositions. The effectiveness of formulated ILs dispersant was found between 70.75% and 94.71% for the dispersion of various crude oils ranging from light to heavy. Further, the acute toxicity tests against zebra fish and grouper fish have revealed the practically non-toxic behaviour of formulated ILs dispersant with LC50 value greater than 100 ppm after 96 h. In addition, the formulated ILs dispersant has provided excellent biodegradability throughout the test period. Overall, the formulated new ILs dispersant is deemed to facilitate environmentally benign oil spill remediation and could effectively substitute the use of hazardous chemical dispersants in immediate future.


Subject(s)
Environmental Restoration and Remediation/methods , Ionic Liquids/analysis , Petroleum Pollution/analysis , Water Pollutants, Chemical/analysis , Animals , Biodegradation, Environmental , Hazardous Substances , Lethal Dose 50 , Petroleum , Surface-Active Agents/chemistry , Toxicity Tests, Acute , Water
11.
Biomacromolecules ; 21(2): 878-891, 2020 02 10.
Article in English | MEDLINE | ID: mdl-31895545

ABSTRACT

Hydrogels of TEMPO-oxidized nanocellulose were stabilized for dry-jet wet spinning using a shell of cellulose dissolved in 1,5-diazabicyclo[4.3.0]non-5-enium propionate ([DBNH][CO2Et]), a protic ionic liquid (PIL). Coagulation in an acidic water bath resulted in continuous core-shell filaments (CSFs) that were tough and flexible with an average dry (and wet) toughness of ∼11 (2) MJ·m-3 and elongation of ∼9 (14) %. The CSF morphology, chemical composition, thermal stability, crystallinity, and bacterial activity were assessed using scanning electron microscopy with energy-dispersive X-ray spectroscopy, liquid-state nuclear magnetic resonance, Fourier transform infrared spectroscopy, thermogravimetric analysis, pyrolysis gas chromatography-mass spectrometry, wide-angle X-ray scattering, and bacterial cell culturing, respectively. The coaxial wet spinning yields PIL-free systems carrying on the surface the cellulose II polymorph, which not only enhances the toughness of the filaments but facilities their functionalization.


Subject(s)
Cellulose/chemical synthesis , Hydrogels/chemical synthesis , Ionic Liquids/chemical synthesis , Nanofibers/chemistry , Cellulose/analysis , Gas Chromatography-Mass Spectrometry/methods , Hydrogels/analysis , Ionic Liquids/analysis , Nanofibers/analysis , Tensile Strength
12.
Chemosphere ; 240: 124947, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31568943

ABSTRACT

This work studies the effect of the cation and anion on the biodegradability and inhibition of imidazolium- and choline-based ionic liquids (ILs) using activated sludge. Six commercial ILs, formed by combination of 1-Butyl-3-methylimidazolium (Bmim+) and N,N,N-trimethylethanolammonium (Choline+) cations and chloride (Cl-), acetate (Ac-) and bis(trifluoromethanesulfonyl)imide (NTf2-) anions were evaluated, all representative counter-ions with markedly different toxicity and biodegradability. Inherent and fast biodegradability tests were used to evaluate both the microorganism inhibition and the IL biodegradability. In addition, the ecotoxicological response (EC50) of the ILs was studied using activated sludge and Vibrio fischeri (Microtox® test). Bmim+ and NTf2- can be considered as non-biodegradable, whereas aerobic microorganisms easily degraded Choline+ and Ac-. The biodegradation pattern of each cation/anion is nearly unaffected by counter-ion nature. Moreover, concentrations of CholineNTf2 higher than 50 mg/L caused a partial inhibition on microbial activity, in good concordance with its low EC50 (54 mg/L) measured by respiration inhibition test, which alerts on the negative environmental impact of NTf2-containing ILs on the performance of sewage treatment plants.


Subject(s)
Aliivibrio fischeri/drug effects , Biodegradation, Environmental , Choline/analysis , Hydrocarbons, Fluorinated/chemistry , Imidazoles/analysis , Imidazoles/chemistry , Imides/chemistry , Quaternary Ammonium Compounds/chemistry , Ecotoxicology , Ionic Liquids/analysis , Sewage/chemistry , Water Purification/methods
13.
Crit Rev Anal Chem ; 49(6): 553-569, 2019.
Article in English | MEDLINE | ID: mdl-31056926

ABSTRACT

The increasing demand of the chiral compounds in drug and food industries has stimulated the considerable attention towards the chiral recognition and separation methods. For this, a number of chiral selectors have been employed for the recognition of enantiomers. In this context, chiral ionic liquids (CILs) have appeared as cheap and lucrative chiral selectors. The present report enlightens the role of CILs in chiral recognition of the enantiomers using various analytical techniques such as NMR and fluorescence spectroscopy, liquid and gas chromatography and capillary electrophoresis. Due to plethora of reports published in this direction, we have tried to limit our discussion about the literature published in the last decade only.


Subject(s)
Chemistry, Analytic , Ionic Liquids/analysis , Chromatography/methods , Electrophoresis, Capillary/methods , Magnetic Resonance Spectroscopy/methods , Spectrometry, Fluorescence/methods
14.
Environ Sci Pollut Res Int ; 26(4): 3145-3156, 2019 Feb.
Article in English | MEDLINE | ID: mdl-29034428

ABSTRACT

The application of the electro-Fenton process for organic compound mineralisation has been widely reported over the past years. However, operational problems related to the use of soluble iron salt as a homogeneous catalyst involve the development of novel catalysts that are able to operate in a wide pH range. For this purpose, polyvinyl alcohol-alginate beads, containing goethite as iron, were synthesised and evaluated as heterogeneous electro-Fenton catalyst for 1-butylpyridinium chloride mineralisation. The influence of catalyst dosage and pH solution on ionic liquid degradation was analysed, achieving almost total oxidation after 60 min under optimal conditions (2 g/L catalyst concentration and pH 3). The results showed good catalyst stability and reusability, although its effectiveness decreases slightly after three successive cycles. Furthermore, a plausible mineralisation pathway was proposed based on the oxidation byproducts determined by chromatographic techniques. Finally, the Microtox® test revealed notable detoxification after treatment which demonstrates high catalyst ability for pyridinium-based ionic liquid degradation by the electro-Fenton process.


Subject(s)
Electrochemical Techniques/methods , Hydrogen Peroxide/chemistry , Ionic Liquids/analysis , Iron/chemistry , Pyridinium Compounds/analysis , Water Pollutants, Chemical/analysis , Water Purification/methods , Catalysis , Chlorides , Oxidation-Reduction
15.
IEEE Trans Nanobioscience ; 17(4): 387-393, 2018 10.
Article in English | MEDLINE | ID: mdl-30281469

ABSTRACT

The dielectric spectroscopy (DS) measurement is an attractive noninvasive method to reveal the intrinsic information of biological materials and cell cultures. However, the presence of a double layer due to electrode polarization within the lower RF and microwave range significantly affects the accurate analysis of dielectric properties of ionic liquids. In this paper, we measure the broadband DS of five saline solutions with a microfluidic coplanar waveguide (CPW) transmission line sensor across the frequency range from 40 kHz to 110 GHz. Derived from a parallel-plate structure that is transformed from the quasi-TEM CPW sensor through a conformal mapping technique, a broadband spectroscopy modeling method is proposed, where a Cole-Cole function or a constant phase element formula is used depending on the ionic concentrations and the measurement window. Validation analysis on the five saline solutions demonstrates the capability of the modeling method in separating relaxation properties of the bulk sample from the double-layer effects.


Subject(s)
Dielectric Spectroscopy , Ionic Liquids/analysis , Ionic Liquids/chemistry , Models, Chemical
16.
Anal Chim Acta ; 1026: 37-50, 2018 Oct 05.
Article in English | MEDLINE | ID: mdl-29852992

ABSTRACT

Ion mobility spectrometry (IMS) is a rapid and high sensitive technique widely used in security and forensic areas. However, a lack of selectivity is usually observed in the analysis of complex samples due to the scarce resolution of the technique. The literature concerning the use of conventional and novel smart materials in the pretreatment and preconcentration of samples previous to IMS determinations has been critically reviewed. The most relevant strategies to enhance selectivity and sensitivity of IMS determinations have been widely discussed, based in the use of smart materials, as immunosorbents, aptamers, molecularly imprinted polymers (MIPs), ionic liquids (ILs) and nanomaterial. The observed trend is focused on the development of IMS analytical methods in combination of selective sample treatments in order to achieve quick, reliable, sensitive, and selective methods for the analysis of complex samples such as biological fluids, food, or environmental samples.


Subject(s)
Analytic Sample Preparation Methods/methods , Aptamers, Nucleotide/analysis , Immunosorbents/analysis , Ion Mobility Spectrometry , Ionic Liquids/analysis , Nanostructures/analysis , Polymers/analysis , Molecular Imprinting
17.
BMC Biotechnol ; 18(1): 32, 2018 05 29.
Article in English | MEDLINE | ID: mdl-29843701

ABSTRACT

BACKGROUND: Solvate ionic liquids (SILs) are a new class of ionic liquids that are equimolar solutions of lithium bistrifluoromethanesulfonimide in either triglyme or tetraglyme, referred to as G3LiTFSA and G4LiTFSA, respectively. SILs play a role in energy storage lithium batteries, and have been proposed as potential alternatives to traditional organic solvents such as DMSO. G3TFSA and G4TFSA have been shown to exhibit no toxicity in vivo up to 0.5% (v/v), and solubilize small compounds (N,N-diethylaminobenzaldehyde) with full penetrance, similar to DMSO delivered DEAB. Herein, we compare the effects of storage (either at room temperature or - 20 °C) on DEAB solubilized in either DMSO, G3TFSA or G4TFSA to investigate compound degradation and efficacy. RESULTS: The findings show that DEAB stored at room temperature (RT) for 4 months solubilized in either G3TFSA, G4TFSA or DMSO displayed no loss of penetrance. The same was observed with stock solutions stored at - 20 °C for 4 months; however G4TFSA remained in a liquid state compared to both G3TFSA and DMSO. Moreover, we examined the ability of G3TFSA and G4TFSA to solubilize another small molecular therapeutic, the FGFR antagonist SU5402. G4TFSA, unlike G3TFSA solubilized SU5402 and displayed similar phenotypic characteristics and reduced dlx2a expression as reported and shown with SU5402 in DMSO; albeit more penetrative. CONCLUSION: This study validates the use of these ionic liquids as a potential replacement for DMSO in vivo as organic solubilizing agents.


Subject(s)
Dimethyl Sulfoxide/analysis , Ionic Liquids/analysis , Small Molecule Libraries , Animals , Models, Animal , Zebrafish
18.
Cell Chem Biol ; 25(8): 952-961.e12, 2018 08 16.
Article in English | MEDLINE | ID: mdl-29805038

ABSTRACT

Cholesterol is an essential component of most biological membranes and serves important functions in controlling membrane integrity, organization, and signaling. However, probes to follow the dynamic distribution of cholesterol in live cells are scarce and so far show only limited applicability. Herein, we addressed this problem by synthesizing and characterizing a class of versatile and clickable cholesterol-based imidazolium salts. We show that these cholesterol analogs faithfully mimic the biophysical properties of natural cholesterol in phospholipid mono- and bilayers, and that they integrate into the plasma membrane of cultured and primary human cells. The membrane-incorporated cholesterol analogs can be specifically labeled by click chemistry and visualized in live-cell imaging experiments that show a distribution and behavior comparable with that of endogenous membrane cholesterol. These results indicate that the cholesterol analogs can be used to reveal the dynamic distribution of cholesterol in live cells.


Subject(s)
Cell Membrane/metabolism , Cholesterol/analogs & derivatives , Cholesterol/metabolism , Imidazoles/metabolism , Cell Survival , Cholesterol/analysis , Click Chemistry , HeLa Cells , Human Umbilical Vein Endothelial Cells , Humans , Imidazoles/analysis , Imidazoles/chemical synthesis , Ionic Liquids/analysis , Ionic Liquids/chemical synthesis , Ionic Liquids/metabolism , Lipid Bilayers/metabolism , Optical Imaging , Spectrometry, Fluorescence , Spectrometry, Mass, Secondary Ion
19.
J Sep Sci ; 41(10): 2237-2244, 2018 May.
Article in English | MEDLINE | ID: mdl-29524324

ABSTRACT

Sulfonamides are antibiotics widely used in the treatment of diseases in dairy cattle. However, their indiscriminate use for disease control may lead to their presence in tissues and milk and their determination requires a sample preparation step as part of an analytical approach. Among the several sample preparation techniques available, those based upon the use of sorptive materials have been widely employed. Recently, the application of ionic liquids immobilized on silica surfaces or polymeric materials has been evaluated for such an application. This manuscript addresses the evaluation of silica-based ionic liquid obtained by a sol-gel synthesis process by basic catalysis as sorbent for online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry for sulfonamides determination. Infrared vibrational spectroscopy confirmed the presence of the ionic liquid on the silica surface, suggesting that the ionic liquid was anchored on to the silica surface. Other sorbents varying the ionic liquid alkyl chain were also synthesized and evaluated by off-line solid-phase extraction in the sulfonamide extraction. As the length of the alkyl chain increased, the amount of extracted sulfonamides decreased, possibly due to a decrease in the electrostatic interaction caused by the reduction in the polarity, as well as the presence of a hexafluorophosphate anion that increases the hydrophobic character of the material. The use of 1-butyl-3-methylimidazolium hexafluorophosphate as a selective ionic liquid sorbent enabled the isolation and sulfonamide preconcentration in bovine milk by online solid-phase extraction with liquid chromatography and electrospray ionization time-of-flight mass spectrometry. The limit of quantification for the method developed was 5-7, 5 µg/mL, with extraction recoveries ranging between 74 and 93% and intra- and interassay between 1.5-12.5 and 2.3-13.1, respectively.


Subject(s)
Food Analysis/methods , Ionic Liquids/analysis , Milk/chemistry , Silicon Dioxide , Sulfonamides/analysis , Animals , Catalysis , Cattle , Chromatography, Liquid , Electronic Data Processing , Internet , Mass Spectrometry , Microscopy, Electron, Scanning , Online Systems , Reproducibility of Results , Solid Phase Extraction , Spectroscopy, Fourier Transform Infrared , Static Electricity
20.
Ecotoxicol Environ Saf ; 147: 480-486, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28910746

ABSTRACT

Ionic liquids (ILs) have been widely used as environmentally friendly solvents to replace volatile organic solvents in the chemistry industries. They have a high water solubility and potential risk to organisms in the soil-water environment. At present, most studies focused on the batch sorption of ILs in soil and neglected the investigation of IL transports in soil, which results in a lack of understanding of the structure-dependent mobility of ILs in the environment. Laboratory-scale sand/soil column experiments were performed to study the transport of imidazolium-based ILs, such as [C4mim][OTF], [C4mim][TOS], [C4mim][MeSO3], [C4mim][BF4], [C2mim][BF4], and [C6mim][BF4] including different counteranions and alkyl chain lengths of IL cations. Batch experiments were also carried out to compare the difference of sorption distribution coefficient (Kd) between the batch and column experiments. A one-dimensional convective-dispersive model using CXTFIT code was created based on the measured breakthrough curves (BTCs) to estimate the column transport parameters. For the anion, [BF4-], the Kd of ILs in both batch and column experiments increased with increasing alkyl chain lengths of the IL cation. In batch tests, counteranions showed no influence on the Kd of [C4mim][OTF], [C4mim][TOS], [C4mim][MeSO3], [C4mim][BF4], [C2mim][BF4], and [C6mim][BF4]. However, in column tests, the BTCs of 1-butyl-3-methylimidazolium-based ILs were anion dependent as evidenced by the change of retardation factor (R) for different counteranions. Furthermore, the effects of transport distance (11cm, 15cm, 19cm, and 24cm) on the mobility of ILs were estimated. The longer distances signified an increase in the contact time and more binding sites for ILs and therefore, the smoother shapes of BTCs in column experiments.


Subject(s)
Imidazoles/analysis , Ionic Liquids/analysis , Models, Theoretical , Silicon Dioxide/chemistry , Soil Pollutants/analysis , Soil/chemistry , Adsorption , Anions , Cations , Imidazoles/chemistry , Ionic Liquids/chemistry , Molecular Structure , Soil Pollutants/chemistry
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