The Experts below are selected from a list of 444 Experts worldwide ranked by ideXlab platform
Huanwen Chen - One of the best experts on this subject based on the ideXlab platform.
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Quantification of Trace Organophosphorus Pesticides in Environmental Water via Enrichment by Magnetic-Zirconia Nanocomposites and Online Extractive Electrospray Ionization Mass Spectrometry.
Analytical Chemistry, 2020Co-Authors: Hua Zhang, Keke Huang, Jiaquan Xu, Siliang Kuang, Huanwen ChenAbstract:A total of 15 representative organophosphorus pesticides (OPPs), a class of water pollutants causing serious global concerns, have been sensitively quantified by internal Extractive Electrospray Ionization mass spectrometry (iEESI-MS) after enrichment with Fe3O4-ZrO2 innovatively synthesized in our lab by a one step coprecipitation method. For the premium enrichment, the amounts of Fe3O4-ZrO2, pH value, adsorption time, type and volume of desorption solvent, and shaking time of desorption were systematically optimized. Under optimized conditions, the proposed method provided low limits of detection (LODs) of 0.14-16.39 ng L(-1) with relative standard deviations (RSDs) of less than 8.7%. A wide linear response range of about 4 orders of magnitude was achieved with linear coefficients (R(2)) of 0.9921-0.9999 for all the analytes tested. The present method also provided good recoveries (85.4-105.9%) with acceptable precision (RSDs < 7.2%) in spiked environmental water samples. Furthermore, multiple analytes including dimethoate, omethoate, etc. were simultaneously detected in a single sample run, which was accomplished within 1 min, resulting in significantly improved analytical throughput for quantitative analysis of bulk amounts of samples. The experimental results demonstrated that Fe3O4-ZrO2-iEESI-MS provided advantages, including high sensitivity, high speed, and reasonable selectivity for the detection of OPPs, showing potential applications in environmental water sample analysis and environmental science.
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capturing hemoglobin on graphene sheet from sub microliter whole blood for quantitative characterization by internal Extractive Electrospray Ionization mass spectrometry
Talanta, 2019Co-Authors: Lili Song, Huanwen Chen, Shuanglong WangAbstract:Abstract A disposable blood sampler, which is consisted of a sub-microliter whole blood collector and a graphene filter, loading graphene sheet to selectively capture hemoglobin from sub-microliter whole blood, was developed for both qualitative and quantitative characterization hemoglobin by internal Extractive Electrospray Ionization mass spectrometry (iEESI-MS). The blood collector was elegantly fabricated in syringe-like fashion for precisely sampling tiny amounts (1.0 μL - 2%) of whole blood, which was immediately diluted by water inside the syringe and was then pressed through the graphene filter placed between the waste outlet and the syringe reservoir to capture the hemoglobin in the blood sample. Then the graphene with hemoglobin was directly eluted by a charged (+2.5 kV) solution (mathanol/water/formic acid, 48/48/4, v/v/v) to produce the hemoglobin ions for mass spectrometric analysis. Low detection-of-limit (19.3 mg L−1 (89.5 picomol)), acceptable linear response range (300–1500 mg L−1, R2 = 0.998), relative standard deviation (0.5–6.5%, n = 3), low sample consumption (≤1.0 μL) and a relatively high speed (≤4 min per sample, including the sample loading) were achieved, demonstrating that the graphene based iEESI-MS was an alternative choice for direct detection of hemoglobin in whole blood with minimal sample consumption.
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combination of low temperature electrosurgical unit and Extractive Electrospray Ionization mass spectrometry for molecular profiling and classification of tissues
Molecules, 2019Co-Authors: G T Sukhikh, Konstantin Chingin, Vitaliy Chagovets, Xinchen Wang, Valeriy Rodionov, Vlada Kometova, A O Tokareva, Alexey Kononikhin, Natalia L Starodubtseva, Huanwen ChenAbstract:Real-time molecular navigation of tissue surgeries is an important goal at present. Combination of electrosurgical units and mass spectrometry (MS) to perform accurate molecular visualization of biological tissues has been pursued by many research groups. Determination of molecular tissue composition at a particular location by surgical smoke analysis is now of increasing interest for clinical use. However, molecular analysis of surgical smoke is commonly lacking molecular specificity and is associated with significant carbonization and chemical contamination, which are mainly related to the high temperature of smoke at which many molecules become unstable. Unlike traditional electrosurgical tools, low-temperature electrosurgical units allow tissue dissection without substantial heating. Here, we show that low-temperature electrosurgical units can be used for desorption of molecules from biological tissues without thermal degradation. The use of Extractive Electrospray Ionization technique for the Ionization of desorbed molecules allowed us to obtain mass spectra of healthy and pathological tissues with high degree of differentiation. Overall, the data indicate that the described approach has potential for intraoperative use.
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high throughput screening of toxic substances by Extractive Electrospray Ionization mass spectrometry and their identification via databank construction
Analytical and Bioanalytical Chemistry, 2019Co-Authors: Shuanglong Wang, Faliang Li, Huian Zhao, Huanwen ChenAbstract:More than 200 toxic substances (including narcotic drugs, psychotropic drugs, organic phosphorus compounds, carbamates, pyrethroids and other pesticides, veterinary drugs, rodenticides, natural toxins, and other drugs) were identified and quantified using an ion-trap mass spectrometer. The advantages of this technique—its selectivity, accuracy, precision, utilization of only small amounts of the sample, and short analysis time for a single sample (less than 30s)—render it a rapid and accurate methodology for toxin screening. Subsequently, an Extractive Electrospray Ionization (EESI) mass spectrometry database was established by combining the Xcalibur data processing system with NIST database software. This allowed unknown toxicants in urine and blood samples, stomach contents, and liver samples, as provided by the Jiangxi Provincial Public Security Department, to be analyzed and identified. This EESI methodology and databank has the potential for widespread application to the large-scale analysis of practical samples.
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generating supercharged protein ions for breath analysis by Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2019Co-Authors: Mufang Ke, Xiang Fang, Jianhua Ding, Konstantin Chingin, Xingchuang Xiong, Hua Zhang, Fenglei Li, Huanwen ChenAbstract:Supercharged protein ions produced by Electrospray Ionization are extremely efficient proton donors for secondary Ionization. Here, by Electrospraying the protein solutions containing 5% 1,2-butylene carbonate, the supercharged protein ions with unusually high proton density were produced as the primary ions for the Ionization of exhaled breath samples in the Extractive Electrospray Ionization mass spectrometry (EESI-MS), which resulted in the enhanced Ionization efficiency for the breath analytes even with relatively low gas phase basicity. Moreover, the total number of metabolites detected in breath increased by about 260% in the mass range of 200–500 Da, owing to the substantial signal enhancement for breath metabolites, providing complementary and additional information to conventional SESI.
Renato Zenobi - One of the best experts on this subject based on the ideXlab platform.
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On the mechanism of Extractive Electrospray Ionization (EESI) in the dual-spray configuration
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Rui Wang, Arto Juhani Gröhn, Rolf Dietiker, Karsten Wegner, Detlef Günther, Renato ZenobiAbstract:Dual-spray Extractive Electrospray Ionization (EESI) mass spectrometry as a versatile analytical technique has attracted much interest due to its advantages over conventional Electrospray Ionization (ESI). The crucial difference between EESI and ESI is that in the EESI process, the analytes are introduced in nebulized form via a neutral spray and ionized by collisions with the charged droplets from an ESI source formed by spraying pure solvent. However, the mechanism of the droplet–droplet interactions in the EESI process is still not well understood. For example, it is unclear which type of droplet–droplet interaction is dominant: bounce, coalescence, disruption, or fragmentation? In this work, droplet–droplet interaction was investigated in detail based on a theoretical model. Phase Doppler anemometry (PDA) was employed to investigate the droplet behavior in the EESI plume and provide the experimental data (droplet size and velocity) necessary for theoretical analysis. Furthermore, numerical simulations were performed to clarify the influence of the sheath gas flow on the EESI process. No coalescence between the droplets in the ESI spray and the droplets in the sample spray was observed using various geometries and sample flow rates. Theoretical analysis, together with the PDA results, suggests that droplet fragmentation may be the dominant type of droplet–droplet interaction in the EESI. The interaction time between the ESI droplet and the sample droplet was estimated to be
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on the mechanism of Extractive Electrospray Ionization eesi in the dual spray configuration
Analytical and Bioanalytical Chemistry, 2012Co-Authors: Rui Wang, Arto Juhani Gröhn, Rolf Dietiker, Karsten Wegner, Detlef Günther, Renato ZenobiAbstract:Dual-spray Extractive Electrospray Ionization (EESI) mass spectrometry as a versatile analytical technique has attracted much interest due to its advantages over conventional Electrospray Ionization (ESI). The crucial difference between EESI and ESI is that in the EESI process, the analytes are introduced in nebulized form via a neutral spray and ionized by collisions with the charged droplets from an ESI source formed by spraying pure solvent. However, the mechanism of the droplet–droplet interactions in the EESI process is still not well understood. For example, it is unclear which type of droplet–droplet interaction is dominant: bounce, coalescence, disruption, or fragmentation? In this work, droplet–droplet interaction was investigated in detail based on a theoretical model. Phase Doppler anemometry (PDA) was employed to investigate the droplet behavior in the EESI plume and provide the experimental data (droplet size and velocity) necessary for theoretical analysis. Furthermore, numerical simulations were performed to clarify the influence of the sheath gas flow on the EESI process. No coalescence between the droplets in the ESI spray and the droplets in the sample spray was observed using various geometries and sample flow rates. Theoretical analysis, together with the PDA results, suggests that droplet fragmentation may be the dominant type of droplet–droplet interaction in the EESI. The interaction time between the ESI droplet and the sample droplet was estimated to be <5 μs. This work gives a clear picture of droplet–droplet interactions in the dual-spray EESI process and detailed information for the optimization of this method for future applications that require higher sensitivity.
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Extractive Electrospray Ionization mass spectrometry enhanced sensitivity using an ion funnel
Analytical Chemistry, 2012Co-Authors: Lukas Meier, Christian Berchtold, Stefan Schmid, Renato ZenobiAbstract:Electrodynamic ion funnel interfaces for Electrospray Ionization (ESI) have shown to enhance the sensitivity of measurements by more than 2 orders of magnitude in the intermediate pressure region of the instrument (1–30 Torr). In this study, we use an ion funnel at ambient pressure to enhance the sensitivity of Extractive Electrospray Ionization (EESI) by spraying directly into the ion funnel. EESI is a powerful Ionization technique that is capable of handling complex matrixes that may contain dozens of compounds. Our results using atenolol, salbutamol, and cocaine as test compounds show that we can improve the limit of detection for these compounds by more than 3 orders of magnitude compared to standard EESI experiments.
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Extractive Electrospray Ionization Mass Spectrometry—Enhanced Sensitivity Using an Ion Funnel
Analytical Chemistry, 2012Co-Authors: Lukas Meier, Christian Berchtold, Stefan Schmid, Renato ZenobiAbstract:Electrodynamic ion funnel interfaces for Electrospray Ionization (ESI) have shown to enhance the sensitivity of measurements by more than 2 orders of magnitude in the intermediate pressure region of the instrument (1–30 Torr). In this study, we use an ion funnel at ambient pressure to enhance the sensitivity of Extractive Electrospray Ionization (EESI) by spraying directly into the ion funnel. EESI is a powerful Ionization technique that is capable of handling complex matrixes that may contain dozens of compounds. Our results using atenolol, salbutamol, and cocaine as test compounds show that we can improve the limit of detection for these compounds by more than 3 orders of magnitude compared to standard EESI experiments.
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contribution of liquid phase and gas phase Ionization in Extractive Electrospray Ionization mass spectrometry of primary amines
European Journal of Mass Spectrometry, 2011Co-Authors: Lukas Meier, Christian Berchtold, Stefan Schmid, Renato ZenobiAbstract:In this study, we investigated how binary mixtures of compounds influence each other’s signal intensity in Electrospray Ionization (ESI), Extractive Electrospray Ionization (EESI) and secondary Electrospray Ionization (SESI) experiments. The experiments were conducted using a series of homologous primary amines (from 1-butyl to 1-decylamine). In every experiment, two of the amines were present, and all 21 possible combinations were measured with EESI, ESI and SESI as Ionization sources. Except for the volatility, which decreases with increasing molecular weight, the physico–chemical properties of the amines are very similar, so that the intensity ratio obtained in each experiment provides information about discrimination effects occurring during the Ionization process. The results show that for the relatively volatile compounds investigated, the EESI Ionization mechanism resembles the SESI-like gas-phase charge transfer more than ESI-like analyte Ionization in solution. In addition, almost no discrimination effects were observed in the spectra obtained in EESI experiments. Quantitative EESI experiments with nonylamine as internal standard showed that EESI is capable of providing both more accurate and more precise results than SESI and ESI.
Haiwei Gu - One of the best experts on this subject based on the ideXlab platform.
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metabolic effects of clenbuterol and salbutamol on pork meat studied using internal Extractive Electrospray Ionization mass spectrometry
Scientific Reports, 2017Co-Authors: Haiyan Lu, Yipo Xiao, H Zhang, Haiwei GuAbstract:Direct mass spectrometry analysis of metabolic effects of clenbuterol and salbutamol on pork quality at the molecular level is incredibly beneficial for food regulations, public health and the development of new anti-obesity drugs. With internal Extractive Electrospray Ionization mass spectrometry (iEESI-MS), nutrients including creatine, amino acids, L-carnitine, vitamin B6, carnosine and phosphatidylcholines in pork tissue were identified, without sample pretreatment, using collision-induced dissociation (CID) experiments and by comparison with authentic compounds. Furthermore, normal pork samples were clearly differentiated from pork samples with clenbuterol and salbutamol via principal component analysis (PCA). Correlation analysis performed on the spectral data revealed that the above-mentioned nutrients strongly correlated with pork quality, and the absolute intensity of phosphatidylcholines in normal pork was much higher than pork contaminated by clenbuterol and salbutamol. Our findings suggested that clenbuterol and salbutamol may render effects on the activity of carnitine acyltransferase I, hence the process that L-carnitine transports long-chain fatty acids into mitochondria and the formation of phosphatidylcholines might be affected. However, the underlying metabolic mechanisms of clenbuterol and salbutamol on carnitine acyltransferase I requires more comprehensive studies in future work.
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quantitative detection of nitric oxide in exhaled human breath by Extractive Electrospray Ionization mass spectrometry
Scientific Reports, 2015Co-Authors: Yong Tian, Ming Li, Jiuyan Zhao, Wei Zhang, Haiwei Gu, Haidong Wang, Xiang Fang, Penghui Li, Huanwen ChenAbstract:Quantitative detection of nitric oxide in exhaled human breath by Extractive Electrospray Ionization mass spectrometry
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direct characterization of bulk samples by internal Extractive Electrospray Ionization mass spectrometry
Scientific Reports, 2013Co-Authors: H Zhang, Haiwei Gu, Nannan Wang, Jianjun Xu, Huanwen ChenAbstract:A straight-forward analytical strategy called internal Extractive Electrospray Ionization mass spectrometry (iEESI-MS), which combines solvent extraction of chemicals inside a bulk sample with in situ Electrospray Ionization mass spectrometry, has been established to directly characterize the interior of a bulk sample with molecular specificity. The method allows both qualitative and quantitative analysis of analytes distributed in a 3-dimensional volume (e.g., 1 ~ 100 mm3) of various synthetic and biological matrices (e.g., chewing gum, leaves, fruits, roots, pork, lung tissues) without either mashing the sample or matrix separation. Using different extraction solvents, online chromatographic separation of chemicals inside the sample volume was observed during iEESI-MS analysis. The presented method is featured by the high speed of analysis, high sensitivity, low sample consumption and minimal sample preparation and/or degradation, offering unique possibilities for advanced applications in plant science, clinical diagnosis, catalyst studies, and materials science.
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facilitated diffusion of acetonitrile revealed by quantitative breath analysis using Extractive Electrospray Ionization mass spectrometry
Scientific Reports, 2013Co-Authors: Ming Li, Haiwei Gu, Huanwen Chen, Jianhua Ding, Yan Zhang, Ning Xu, Hongmei LiAbstract:Facilitated Diffusion of Acetonitrile Revealed by Quantitative Breath Analysis Using Extractive Electrospray Ionization Mass Spectrometry
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detection of trace levels of lead in aqueous liquids using Extractive Electrospray Ionization tandem mass spectrometry
Talanta, 2012Co-Authors: Xinglei Zhang, Haiwei Gu, Ning Xu, Saijin Xiao, Huanwen ChenAbstract:A sensitive approach, based on semi-quantitative measurement of the characteristic fragments in multistage Extractive Electrospray Ionization mass spectrometry (EESI-MSn), was developed for fast detection of trace levels of lead in aqueous liquids including mineral water, lake water, tap water, energy drinks, soft drinks, beer, orange juice, and tea. A disodium ethylene-diamine-tetraacetic acid (EDTA) aqueous solution was Electrosprayed to produce negatively charged primary ions which then intersected the neutral sample plume to generate anions of EDTA-Pb(II) complexes. The charged EDTA-Pb(II) complexes were characterized with multistage collision induced dissociation (CID) experiments. The limit of detection (LOD) using EESI-MS3 was estimated to be at the level of 10(-13) g/mL for directly detecting lead in many of these samples. The linear dynamic range was higher than 2 orders of magnitude. A single sample analysis could be completed within 2 min with reasonable semi-quantitative performance, e.g., relative standard deviations (RSDs) for deionized water were 4.6-7.6% during 5 experimental runs (each of them had 10 repeated measurements). Coca-cola and Huiyuan orange juice, representative beverage samples with complex matrices, generated recovery rates of 91.5% and 129%, respectively. Our experimental data demonstrated that EESI-MS is a useful tool for the fast detection of lead in various solutions, and EESI-MS showed promises for fast screening of lead-contaminated aqueous liquid samples. (C) 2012 Elsevier B.V. All rights reserved,
Urs Baltensperger - One of the best experts on this subject based on the ideXlab platform.
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real time detection of aerosol metals using online Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2020Co-Authors: Stamatios Giannoukos, Mohamed Tarik, Christian Ludwig, Serge M.a. Biollaz, Houssni Lamkaddam, Urs Baltensperger, André S. H. Prévôt, Jay G. SlowikAbstract:Metal emissions are of major environmental and practical concern because of their highly toxic effects on human health and ecosystems. Current technologies available in the market for their detection are typically limited by a time resolution of 1 h or longer (e.g., via semicontinuous X-ray fluorescence measurements) or are nonquantitative (e.g., laser ablation mass spectrometry). In this work, we report the development of a novel technique for the real-time detection and monitoring of metal particles in situ using an Extractive Electrospray Ionization (EESI) source coupled to a high-resolution time-of-flight mass spectrometer (TOF-MS). The experiments were conducted in negative Ionization mode using disodium ethylenediamine tetraacetic acid (EDTA) dihydrate to chelate with metals and form stable metal complexes. Results for water-soluble metal compounds were obtained. The following representative metal ions were examined: Pb, Cd, Zn, Ce (III), Ba, Ni, Fe(II), Fe(III), Cu(II), Cr, Mo, Co(II), Mg, Nd, Li, Ti, Ca, Cs, Ag, Tm, Er(III), La(III), Yb(III), Eu(III), Pr(III), Gd(III), Lu(III), Dy(III), Tb(III), Ho, and Ru(III). The results showed a very good linear mass response (R(2) = 0.9983), low ng/m(3) limits of detection (LoD), and a fast response time (1 s). The stability and repeatability of the developed EESI-TOF-MS were tested under complex dynamic and periodic experimental conditions, and negligible matrix effects were measured for internally and externally mixed metal particles. Benchmark testing against inductively coupled plasma-mass spectrometry (ICP-MS) was also performed, highlighting the online measurement capabilities of aerosol metals with a LoD lower than those of ICP-MS. Proof-of-concept ambient measurements were performed in New Delhi, India, and very promising results were obtained, allowing further exploitation elsewhere.
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Real-time detection of aerosol metals using on-line Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2019Co-Authors: Stamatios Giannoukos, Mohamed Tarik, Christian Ludwig, Serge M.a. Biollaz, Houssni Lamkaddam, Urs Baltensperger, André S. H. Prévôt, Jay G. SlowikAbstract:Metal emissions are of major environmental and practical concern due to their highly toxic effects on human health and ecosystems. Current technologies available in the market for their detection are typically limited by time-resolution of 1 hour or slower (e.g. via semi-continuous X-ray fluorescence measurements) or non-quantitative (e.g. laser ablation mass spectrometry). In this work, we report the development of a novel technique for the real-time detection and monitoring of metal particles in-situ using an Extractive Electrospray Ionization (EESI) source coupled to a high-resolution time-of-flight mass spectrometer (TOF-MS). The experiments were conducted in the negative Ionization mode using disodium ethylenediamine tetraacetic acid (EDTA) dihydrate to chelate with metals and form stable metal complexes. Results for water-soluble metal compounds were obtained. The following representative metal ions were examined: Pb, Cd, Zn, Ce (III), Ba, Ni, Fe (II), Fe (III), Cu (II), Cr, Mo, Co (II), Mg, Nd, Li,...
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organic aerosol source apportionment in zurich using an Extractive Electrospray Ionization time of flight mass spectrometer eesi tof ms part 1 biogenic influences and day night chemistry in summer
Atmospheric Chemistry and Physics, 2019Co-Authors: Giulia Stefenelli, Urs Baltensperger, André S. H. Prévôt, F Lopezhilfiker, Veronika Pospisilova, Kaspar R Daellenbach, Yandong Tong, Christoph Huglin, Jay G. SlowikAbstract:Abstract. Improving the understanding of the health and climate impacts of aerosols remains challenging and is restricted by the limitations of current measurement techniques. Detailed investigation of secondary organic aerosol (SOA), which is typically the dominating fraction of the organic aerosol (OA), requires instrumentation capable of real-time, in situ measurements of molecular composition. In this study, we present the first ambient measurements by a novel Extractive Electrospray Ionization time-of-flight mass spectrometer (EESI-TOF-MS). The EESI-TOF-MS was deployed along with a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) during summer 2016 at an urban location (Zurich, Switzerland). Positive matrix factorization (PMF), implemented within the Multilinear Engine (ME-2), was applied to the data from both instruments to quantify the primary and secondary contributions to OA. From the EESI-TOF-MS analysis, a six-factor solution was selected as the most representative and interpretable solution for the investigated dataset, including two primary and four secondary factors. The primary factors are dominated by cooking and cigarette smoke signatures while the secondary factors are discriminated according to their daytime (two factors) and night-time (two factors) chemistry. All four factors showed strong influence by biogenic emissions but exhibited significant day–night differences. Factors dominating during daytime showed predominantly ions characteristic of monoterpene and sesquiterpene oxidation while the night-time factors included less oxygenated terpene oxidation products, as well as organonitrates which were likely derived from NO3 radical oxidation of monoterpenes. Overall, the signal measured by the EESI-TOF-MS and AMS showed a good correlation. Further, the two instruments were in excellent agreement in terms of both the mass contribution apportioned to the sum of POA and SOA factors and the total SOA signal. However, while the oxygenated organic aerosol (OOA) factors separated by AMS analysis exhibited a flat diurnal pattern, the EESI-TOF-MS factors illustrated significant chemical variation throughout the day. The captured variability, inaccessible from AMS PMF analysis, was shown to be consistent with the variations in the physiochemical processes influencing chemical composition and SOA formation. The improved source separation and interpretability of EESI-TOF-MS results suggest it to be a promising approach to source apportionment and atmospheric composition research.
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an Extractive Electrospray Ionization time of flight mass spectrometer eesi tof for online measurement of atmospheric aerosol particles
Atmospheric Measurement Techniques, 2019Co-Authors: F Lopezhilfiker, Urs Baltensperger, Markus Kalberer, Veronika Pospisilova, Wei Huang, Claudia Mohr, Giulia Stefenelli, J A Thornton, André S. H. PrévôtAbstract:Abstract. Real-time, online measurements of atmospheric organic aerosol (OA) composition are an essential tool for determining the emissions sources and physicochemical processes governing aerosol effects on climate and health. However, the reliance of current techniques on thermal desorption, hard Ionization, and/or separated collection/analysis stages introduces significant uncertainties into OA composition measurements, hindering progress towards these goals. To address this gap, we present a novel, field-deployable Extractive Electrospray Ionization time-of-flight mass spectrometer (EESI-TOF), which provides online, near-molecular (i.e., molecular formula) OA measurements at atmospherically relevant concentrations without analyte fragmentation or decomposition. Aerosol particles are continuously sampled into the EESI-TOF, where they intersect a spray of charged droplets generated by a conventional Electrospray probe. Soluble components are extracted and then ionized as the droplets are evaporated. The EESI-TOF achieves a linear response to mass, with detection limits on the order of 1 to 10 ng m −3 in 5 s for typical atmospherically relevant compounds. In contrast to conventional Electrospray systems, the EESI-TOF response is not significantly affected by a changing OA matrix for the systems investigated. A slight decrease in sensitivity in response to increasing absolute humidity is observed for some ions. Although the relative sensitivities to a variety of commercially available organic standards vary by more than a factor of 30, the bulk sensitivity to secondary organic aerosol generated from individual precursor gases varies by only a factor of 15. Further, the ratio of compound-by-compound sensitivities between the EESI-TOF and an iodide adduct FIGAERO-I-CIMS varies by only ±50 %, suggesting that EESI-TOF mass spectra indeed reflect the actual distribution of detectable compounds in the particle phase. Successful deployments of the EESI-TOF for laboratory environmental chamber measurements, ground-based ambient sampling, and proof-of-concept measurements aboard a research aircraft highlight the versatility and potential of the EESI-TOF system.
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organic aerosol source apportionment in zurich using an Extractive Electrospray Ionization time of flight mass spectrometer eesi tof ms part 2 biomass burning influences in winter
Atmospheric Chemistry and Physics, 2019Co-Authors: Veronika Pospisilova, Giulia Stefenelli, Lu Qi, Mindong Chen, Yandong Tong, Amelie Bertrand, Christoph Hueglin, Xinlei Ge, Urs BaltenspergerAbstract:Abstract. Real-time, in situ molecular composition measurements of the organic fraction of fine particulate matter (PM 2.5 ) remain challenging, hindering a full understanding of the climate impacts and health effects of PM 2.5 . In particular, the thermal decomposition and Ionization-induced fragmentation affecting current techniques has limited a detailed investigation of secondary organic aerosol (SOA), which typically dominates OA. Here we deploy a novel Extractive Electrospray Ionization time-of-flight mass spectrometer (EESI-TOF-MS) during winter 2017 in downtown Zurich, Switzerland, which overcomes these limitations, together with an Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-TOF-AMS) and supporting instrumentation. Positive matrix factorization (PMF) implemented within the Multilinear Engine (ME-2) program was applied to the EESI-TOF-MS data to quantify the primary and secondary contributions to OA. An 11-factor solution was selected as the best representation of the data, including five primary and six secondary factors. Primary factors showed influence from cooking, cigarette smoke, biomass burning (two factors) and a special local unknown event occurred only during two nights. Secondary factors were affected by biomass burning (three factors, distinguished by temperature and/or wind direction), organonitrates, monoterpene oxidation, and undetermined regional processing, in particular the contributions of wood combustion. While the AMS attributed slightly over half the OA mass to SOA but did not identify its source, the EESI-TOF-MS showed that most ( >70 %) of the SOA was derived from biomass burning. Together with significant contributions from less aged biomass burning factors identified by both AMS and EESI-TOF-MS, this firmly establishes biomass burning as the single most important contributor to OA mass at this site during winter. High correlation was obtained between EESI-TOF-MS and AMS PMF factors where specific analogues existed, as well as between total signal and POA–SOA apportionment. This suggests the EESI-TOF-MS apportionment in the current study can be approximately taken at face value, despite ion-by-ion differences in relative sensitivity. The apportionment of specific ions measured by the EESI-TOF-MS (e.g., levoglucosan, nitrocatechol, and selected organic acids) and utilization of a cluster analysis-based approach to identify key marker ions for the EESI-TOF-MS factors are investigated. The interpretability of the EESI-TOF-MS results and improved source separation relative to the AMS within this pilot campaign validate the EESI-TOF-MS as a promising approach to source apportionment and atmospheric composition research.
Konstantin Chingin - One of the best experts on this subject based on the ideXlab platform.
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in situ study of metabolic response of arabidopsis thaliana leaves to salt stress by neutral desorption Extractive Electrospray Ionization mass spectrometry
Journal of Agricultural and Food Chemistry, 2019Co-Authors: Dong Wu, Yalian Zhou, Wenjing Wang, Konstantin ChinginAbstract:Abstract：Salt stress is one of the most common factors limiting plant cultivation. In this study, metabolic responses to salt stress in Arabidopsis thaliana (A. thaliana) leaves were analyzed in situ by neutral desorption-Extractive Electrospray Ionization mass spectrometry (ND-EESI-MS) without any sample pretreatment. Metabolic changes of A. thaliana leaves were observed in response to salt stress conditions, including the levels of serine, glutamic acid, arginine, cinnamic acid, ferulic acid, caffeic acid, protocatechuic acid, epicatechin, morin, myricetin, apigravin and β-cotonefuran. The content of serine increased under 50, 100 and 200 mM NaCl salt stress, reaching to the highest level at 200 mM NaCl, but decreased under the maximum concentration of 300 mM NaCl. Similar phenomenon was observed for arginine, glutamic acid, cinnamic acid, caffeic acid, ferulic acid and epicatechin respectively involved in the metabolic pathway of shikimate-phenylpropanoid. Both principal component analysis (PCA) and pa...
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combination of low temperature electrosurgical unit and Extractive Electrospray Ionization mass spectrometry for molecular profiling and classification of tissues
Molecules, 2019Co-Authors: G T Sukhikh, Konstantin Chingin, Vitaliy Chagovets, Xinchen Wang, Valeriy Rodionov, Vlada Kometova, A O Tokareva, Alexey Kononikhin, Natalia L Starodubtseva, Huanwen ChenAbstract:Real-time molecular navigation of tissue surgeries is an important goal at present. Combination of electrosurgical units and mass spectrometry (MS) to perform accurate molecular visualization of biological tissues has been pursued by many research groups. Determination of molecular tissue composition at a particular location by surgical smoke analysis is now of increasing interest for clinical use. However, molecular analysis of surgical smoke is commonly lacking molecular specificity and is associated with significant carbonization and chemical contamination, which are mainly related to the high temperature of smoke at which many molecules become unstable. Unlike traditional electrosurgical tools, low-temperature electrosurgical units allow tissue dissection without substantial heating. Here, we show that low-temperature electrosurgical units can be used for desorption of molecules from biological tissues without thermal degradation. The use of Extractive Electrospray Ionization technique for the Ionization of desorbed molecules allowed us to obtain mass spectra of healthy and pathological tissues with high degree of differentiation. Overall, the data indicate that the described approach has potential for intraoperative use.
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generating supercharged protein ions for breath analysis by Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2019Co-Authors: Mufang Ke, Xiang Fang, Jianhua Ding, Konstantin Chingin, Xingchuang Xiong, Hua Zhang, Fenglei Li, Huanwen ChenAbstract:Supercharged protein ions produced by Electrospray Ionization are extremely efficient proton donors for secondary Ionization. Here, by Electrospraying the protein solutions containing 5% 1,2-butylene carbonate, the supercharged protein ions with unusually high proton density were produced as the primary ions for the Ionization of exhaled breath samples in the Extractive Electrospray Ionization mass spectrometry (EESI-MS), which resulted in the enhanced Ionization efficiency for the breath analytes even with relatively low gas phase basicity. Moreover, the total number of metabolites detected in breath increased by about 260% in the mass range of 200–500 Da, owing to the substantial signal enhancement for breath metabolites, providing complementary and additional information to conventional SESI.
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selective enrichment of phosphopeptides and phospholipids from biological matrixes on tio2 nanowire arrays for direct molecular characterization by internal Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2018Co-Authors: Hua Zhang, Huanwen Chen, Konstantin Chingin, Keke Huang, Haiyan Lu, Jiajia LiAbstract:Rapid analysis of phosphopeptides and phospholipids in biological matrixes is of significant interest in multiple disciplines of life sciences. Herein, trace phospholipids in human plasma, whole blood, and undiluted human urine as well as phosphopeptides in protein digest were selectively captured on a homemade array of TiO2 nanowires for sensitive characterization by internal Extractive Electrospray Ionization mass spectrometry (TiO2-iEESI-MS). Sequential release of captured chemicals from TiO2 array was achieved by tuning pH of the extraction solvent. A single sample analysis, including sample loading, chemical extraction and MS detection, was accomplished within 3 min. As far as the quantification of phospholipids, acceptable linearity (R2 ≥ 0.9985) and relative standard deviations (RSDs ≤ 8.9%) were obtained within the range of 0.1–500 μg L–1 for LysoPC(14:0) and LysoPC(16:0) in raw urine samples. Limit of detection (LOD) ≤ 0.025 μg L–1 and recovery rates of 94.8–101.6% were obtained for these phospho...
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quantitative determination of bulk molecular concentrations of β agonists in pork tissue samples by direct internal Extractive Electrospray Ionization mass spectrometry
Analytical Chemistry, 2017Co-Authors: Jiaquan Xu, Konstantin Chingin, Yipo Xiao, Haiyan Lu, Shengrui Xu, Huanwen ChenAbstract:Rapid quantitative determination of bulk molecular concentration in solid samples without sample pretreatment is demonstrated using the internal Extractive Electrospray Ionization-mass spectrometry (iEESI-MS) analysis of six β-agonists, including salbutamol (Sal), clenbuterol (Cle), ractopamine (Rac), terbutaline (Ter), tulobuterol (Tul), brombuterol (Bro), in pork tissue samples. Single sample analysis only required 1 min. The linear range of detection was about 0.01–1000 μg/kg (R2 > 0.9994). The limit-of-detection (LOD) varied from 0.002 μg/kg for Sal to 0.006 μg/kg for Tul. Relative standard deviation (RSD) of quantitation was in the range 6.5–11.3%. The analytical results were validated by gas chromatography–mass spectrometry (GC–MS) and high-performance liquid chromatography–mass spectrometry (LC–MS), showing the accuracy rates of 92–105%. The current study extends the power of ambient MS as a method for the quantification of molecules at the surface of solid samples (e.g., in μg/cm2 units) toward th...
