Alena Kubátová

University of North Dakota

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Evguenii Kozliak

University of North Dakota

Wayne Seames

University of North Dakota

Anastasia A. Andrianova

University of North Dakota

Steven B. Hawthorne

University of North Dakota

Josef Beránek

Pacific Northwest National Laboratory

Irina P. Smoliakova

University of North Dakota

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V. Šašek

Czech Academy of Sciences

Richard E. Cochran

Thermo Fisher Scientific (United States)

Feng Xiao

University of Missouri

JŠ

Jana Šťávová

University of North Dakota

Cooperative Institutions

University of North Dakota

136

Cornell University

Pacific Northwest National Laboratory

Czech Academy of Sciences

University of Colorado Boulder

Charles University

Cooperative Institute for Research in Environmental Sciences

Brookhaven National Laboratory

NOAA Earth System Research Laboratory

Environmental Protection Agency

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Application of 13C-labelled polychlorinated biphenyl congener 153 as internal standard in the gas chromatographic-mass spectrometric analysis of polychlorinated biphenyls

Journal of Chromatography A (1996)

Alena Kubátová M. Matucha Μ. Bubner

Polychlorinated biphenyl

Congener

Biphenyl

Qualitative analysis

Quantitative Analysis

Capillary gas chromatography

10.1016/0021-9673(96)00282-8

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Citations (4)

Pressurised fluid extraction of polycyclic aromatic hydrocarbons and their polar oxidation products from atmospheric particles

International Journal of Environmental & Analytical Chemistry (2015)

Richard E. Cochran Alena Kubátová

An effective method utilising pressurised fluid extraction (PFE) to simultaneously extract polycyclic aromatic hydrocarbons (PAHs) and their polar oxidation products from atmospheric particulate matter (PM) is presented. The PFE method is advantageous over the traditional Soxhlet extraction due to its lower solvent consumption (9 mL compared to 90 mL) and shorter extraction time (15 min versus 18 h). Seventy compounds including PAHs and polar PAH oxidation products containing carbonyl (oxy-PAHs), hydroxyl (hydroxy-PAHs), and carboxylic acid (carboxy-PAHs) groups were targeted in the extraction of two different PM matrices: wood smoke (WS) and diesel exhaust (DE) PM. The PFE method was optimised and then compared to Soxhlet extraction for both PM matrices. The overall amounts of PAHs and their derivatives extracted from WS PM were slightly higher for the optimised PFE method (1849 ± 21 and 1863 ± 25 µg g−1 with dichloromethane (DCM) and methanol (MeOH), respectively) than those obtained with Soxhlet extraction (1726 ± 33 and 1769 ± 22 µg g−1 with DCM and MeOH, respectively). For DE PM (standard reference material (SRM) 2975) the overall amounts extracted by both methods were similar (average of 165 ± 6 µg g−1), agreeing with previously published values. The detailed evaluation of extraction efficiencies for WS PM showed similar amounts for unfunctionalised PAHs (1100 µg g−1) for both methods and solvents. For DE PM the mass yields for PAHs using PFE with DCM (62 ± 1 µg g−1) were the highest and nearly 20% higher than those obtained with MeOH (53 ± 2 µg g−1). The total mass yields of carboxy and hydroxy-PAHs from WS PM were also similar (412 ± 18 and 407 ± 11 µg g−1) for PFE and Soxhlet with MeOH, and higher than when DCM was used (371 ± 5 and 379 ± 12 µg g−1 for PFE and Soxhlet, respectively). For both matrices, the PFE yields for oxy-PAHs were higher than those obtained with Soxhlet.

Dichloromethane

10.1080/03067319.2015.1025225

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Citations (13)

Current Approaches to Subcritical Water Treatment of Lignin

Alena Kubátová Md. Musfiqur Rahman Audrey La Vallie Honza Bílek Evguenii Kozliak

10.1201/9780367694265-eppmpt30-1

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Citations (0)

Radiation damage from EELS and NEXAFS in diesel soot and diesel soot extracts

Journal of Electron Spectroscopy and Related Phenomena (2007)

Artur Braun Alena Kubátová S. Wirick Simon Mun

XANES

Carbon fibers

10.1016/j.elspec.2007.08.002

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Citations (76)

Selective extraction of oxygenates from savory and peppermint using subcritical water

Flavour and Fragrance Journal (2001)

Alena Kubátová Arnaud J. M. Lagadec David J. Miller Steven B. Hawthorne

The yields of oxygenated and non-oxygenated flavour and fragrance compounds from savory (Satureja hortensis) and peppermint (Mentha piperita) were compared using subcritical water extraction, supercritical carbon dioxide extraction (SFE) and hydrodistillation. Extraction rates with subcritical water increased with temperature (100–175 °C), but some desired organics (linalool and γ-terpinene) showed substantial degradation at temperatures >150 °C. However, subcritical water did not expose extracted compounds to atmospheric oxygen (as occurs in hydrodistillation) and thus may avoid the degradation of compounds like thymoquinone. Extraction of savory with subcritical water at 100 °C for 40 min gave ca. 100% recoveries (compared to hydrodistillation) for thymol and carvacrol, and >150% recoveries of borneol and linalool. Recoveries with 60 min of SFE (pure CO2 at 400 bar and 50 °C) were similar to hydrodistillation for borneol and linalool, but only ca. 50% for thymol and carvacrol. For peppermint, 30 min (at 150 °C) or 12 min (at 175 °C) of subcritical water extraction and 1 h of SFE gave good quantitative agreement with 4 h of hydrodistillation for carvone, pulegone, piperitone, eucalyptol, menthone, neomenthol and menthol, but the short subcritical water extractions only recovered ca. 40% of the less polar menthyl acetate. Subcritical water preferentially extracts more polar (oxygenated) flavour compounds, and ca. 80% extraction of oxygenated flavour compounds could be achieved under conditions which only extracted ca. 10–15% of the monoterpenes and <5% of the sesquiterpenes. In contrast, SFE had the lowest degree of selectivity and SFE extracts included plant alkane waxes as well as the same flavour compounds recovered by hydrodistillation. Copyright © 2001 John Wiley & Sons, Ltd.

Oxygenate

10.1002/1099-1026(200101/02)16:1<64::aid-ffj949>3.3.co;2-4

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Citations (2)

Triacylglyceride Thermal Cracking: Pathways to Cyclic Hydrocarbons

Energy & Fuels (2011)

Alena Kubátová Jana Šťávová Wayne Seames Yan Luo Seyed Mojtaba Sadrameli

Thermal cracking of triacylglyceride (TG) oils results in complex mixtures, containing nearly 20% cyclic hydrocarbons, which can be further processed into middle-distillate transportation fuels and byproduct chemicals. The occurrence patterns of cyclic products obtained via the thermal cracking of several TG feedstocks, such as canola and soybean oils, as well as triolein and tristearin (conducted at 430–440 °C in the absence of catalysts under vacuum), were investigated to probe possible formation mechanisms. Detailed gas chromatographic characterization furnished full molar homology/molecular size and partial isomeric profiles for cyclopentanes, cyclopentenes, cyclohexanes, cyclohexenes, aromatics, and polycyclic aromatic hydrocarbons (PAHs). It was found that the data were inconsistent with previously proposed mechanisms involving the Diels–Alder reaction as a single pathway. An alternate mechanism was proposed and supported with experimental evidence based on the intramolecular cyclization of alkenyl and alkadienyl radicals formed as a result of TG cracking. The product homology profiles corroborate the proposed mechanism and show the depletion of medium-size alkenes coupled with the accumulation of corresponding monocyclic hydrocarbons (those with the matching number of carbon atoms). Similarly, the product mixtures were depleted of long-chain alkyl-substituted monocyclic hydrocarbons because of the formation of the corresponding PAHs as long as sufficient time is available. Entropy appears to determine the type and size of cyclic hydrocarbons formed.

Alkane

Triolein

Cyclopentanes

Benzothiophene

10.1021/ef200953d

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Citations (81)

Metformin Uptake and Translocation in Chickpeas: Determination Using Liquid Chromatography–Mass Spectrometry

ACS Omega (2020)

Brett Nespor Anastasia A. Andrianova Sean Pollack Creighton Pfau Muhammad Arifuzzaman

Multiple chronic conditions (MCCs) such as diabetes, hypertension, heart disease, arthritis, asthma, and common respiratory problems are prevalent in over one-fourth of Americans, and separate drugs are prescribed to manage each of the diseases. The nutritive crop seeds loaded with multiple drugs could be a cheap and sustainable alternative to drugs produced by pharmaceutical companies. Our long-term goal is to produce chickpea seeds containing comparable dosages of multiple drugs regularly prescribed for managing MCC. In this work, we conducted experiments to understand the uptake and translocation of metformin into the tissues of chickpea to demonstrate the applicability of LC–HR-ToF-MS in determining metformin concentration, and to investigate responses of increased dosage of metformin and it's accumulation into the chickpea seed. We treated the chickpea plants with 100 and 500 mg/L metformin chloride and analyzed its concentration in the leaf, stem, and seeds. We observed that metformin was successfully uptaken by chickpeas plant and translocated to stem, leaf, and seeds in both treatments. We also observed that the metformin concentration is responsive and as high as 349 times increase in seed when the dosage was increased from 100 to 500 mg/L.

Dose

10.1021/acsomega.9b02783

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Citations (10)

Electrospray Ionization with High-Resolution Mass Spectrometry as a Tool for Lignomics: Lignin Mass Spectrum Deconvolution

Journal of the American Society for Mass Spectrometry (2018)

Anastasia A. Andrianova Thomas J. DiProspero Clayton Geib Irina P. Smoliakova Evguenii Kozliak

The capability to characterize lignin, lignocellulose, and their degradation products is essential for the development of new renewable feedstocks. Electrospray ionization high-resolution time-of-flight mass spectrometry (ESI-HR TOF-MS) method was developed expanding the lignomics toolkit while targeting the simultaneous detection of low and high molecular weight (MW) lignin species. The effect of a broad range of electrolytes and various ionization conditions on ion formation and ionization effectiveness was studied using a suite of mono-, di-, and triarene lignin model compounds as well as kraft alkali lignin. Contrary to the previous studies, the positive ionization mode was found to be more effective for methoxy-substituted arenes and polyphenols, i.e., species of a broadly varied MW structurally similar to the native lignin. For the first time, we report an effective formation of multiply charged species of lignin with the subsequent mass spectrum deconvolution in the presence of 100 mmol L-1 formic acid in the positive ESI mode. The developed method enabled the detection of lignin species with an MW between 150 and 9000 Da or higher, depending on the mass analyzer. The obtained M n and Mw values of 1500 and 2500 Da, respectively, were in good agreement with those determined by gel permeation chromatography. Furthermore, the deconvoluted ESI mass spectrum was similar to that obtained with matrix-assisted laser desorption/ionization (MALDI)-HR TOF-MS, yet featuring a higher signal-to-noise ratio. The formation of multiply charged species was confirmed with ion mobility ESI-HR Q-TOF-MS. Graphical Abstract ᅟ.

Mass spectrometry imaging

10.1007/s13361-018-1916-z

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Citations (30)

Authenticity and Psychological Safety: Building and Encouraging Talent Among Underrepresented Students in STEM

Teaching & Learning Inquiry The ISSOTL Journal (2022)

Daphne E. Pedersen Alena Kubátová Rebecca B. Simmons

The Undergraduate Scholarships with Mathematics and Science Training, Exploration, and Research Program (US MASTER) is a STEM scholarship program funded by the United States National Science Foundation. It was implemented at an upper-Midwest institution to target and provide structured support to low-income, academically talented undergraduates in biology, chemistry, geography and geographic information science (GISc), environmental sciences, and physics and astrophysics. In addition to providing financial support, the program features an integrated approach to mentorship and advising consisting of an ongoing seminar course in which students engage in collaborative projects, research experiences with a faculty mentor, and targeted academic advising. As part of our assessment efforts, we interviewed student participants regarding their experiences. A consistent theme emerged regarding mentorship: in addition to providing access to professional socialization experiences and the facilitation of competency and performance, students reported that it was the ability to form close relationships based on personal authenticity and feelings of psychological safety and trust that provided the best scaffolding for success in a challenging STEM environment.

Mentorship

Undergraduate research

Socialization

10.20343/teachlearninqu.10.31

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Citations (5)

Toward Distinguishing Woodsmoke and Diesel Exhaust in Ambient Particulate Matter

Environmental Science & Technology (2007)

Artur Braun Frank E. Huggins Alena Kubátová S. Wirick M. Matti Maricq

Particulate matter (PM) from biomass burning and diesel exhaust has distinct X-ray spectroscopic, carbon specific signatures, which can be employed for source apportionment. Characterization of the functional groups of a wide selection of PM samples (woodsmoke, diesel soot, urban air PM) was carried out using the soft X-ray spectroscopy capabilities at the synchrotron radiation sources in Berkeley (ALS) and Brookhaven (NSLS). The spectra reveal that diesel exhaust particulate (DEP) matter is made up from a semigraphitic solid core and soluble organic matter, predominantly with carboxylic functional groups. Woodsmoke PM has no or a less prevalent, graphitic signature, instead it contains carbon−hydroxyl groups. Using these features to apportion the carbonaceous PM in ambient samples we estimate that the relative contribution of DEP to ambient PM in an urban area such as Lexington, KY and St. Louis, MO is 7% and 13.5%, respectively. These values are comparable to dispersion modeling data from nonurban and urban areas in California, and with elemental carbon measurements in urban locations such as Boston, MA, Rochester, NY, and Washington, DC.

Carbon fibers

10.1021/es071260k

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Citations (41)