A5065275162- Methane Hydrates and Related Phenomena
- Geophysics and Gravity Measurements
- Ionosphere and magnetosphere dynamics
- Solar and Space Plasma Dynamics
- Mass Spectrometry Techniques and Applications
- Microfluidic and Capillary Electrophoresis Applications
- Advanced Proteomics Techniques and Applications
- Analytical Chemistry and Chromatography
- Advanced biosensing and bioanalysis techniques
- Isotope Analysis in Ecology
- Analytical chemistry methods development
- Biosensors and Analytical Detection
- Microfluidic and Bio-sensing Technologies
- Monoclonal and Polyclonal Antibodies Research
- Protein purification and stability
- Petroleum Processing and Analysis
- Lipid Membrane Structure and Behavior
- Hydrocarbon exploration and reservoir analysis
- Advanced Chemical Sensor Technologies
- DNA and Nucleic Acid Chemistry
- Gene expression and cancer classification
- Identification and Quantification in Food
- SARS-CoV-2 and COVID-19 Research
- Molecular Sensors and Ion Detection
- Biodiesel Production and Applications
Pacific Northwest National Laboratory
2016-2023
Battelle
2021-2022
Leco Corporation (United States)
2013-2018
Richland College
2018
University of Notre Dame
2010-2015
University of Washington
2008-2010
Abstract We report a simple nanospray sheath‐flow interface for capillary electrophoresis. This relies on electrokinetic flow to drive both the separation and electrospray; no mechanical pump is used sheath flow. system was interfaced with an LCQ mass spectrometer. The best results were observed 2‐µm diameter emitter tip 1‐mm spacing between tip. Under these conditions, detection limits (3 σ ) of 100 amol obtained insulin receptor fragment 1142‐1153. efficiency exceeded 200,000 plates this...
We demonstrate the use of capillary zone electrophoresis with an electrokinetically pumped sheath-flow electrospray interface for analysis a tryptic digest sample intermediate protein complexity, secreted fraction Mycobacterium marinum. For electrophoretic analysis, 11 fractions were generated from using reverse-phase liquid chromatography; each was analyzed by CZE-ESI-MS/MS, and 334 peptides corresponding to 140 proteins identified in 165 min mass spectrometer time at 95% confidence (FDR <...
Understanding the biological roles and mechanisms of lipids glycolipids is challenging due to vast number possible isomers that may exist. Mass spectrometry (MS) measurements are currently dominant approach for studying providing detailed information on lipid glycolipid presence changes. However, difficulties in distinguishing many structural isomers, distinct acyl chain positions, double bond locations or specific glycan types, inhibit delineation assignment their roles. Here we utilized...
We report on separations of ion isotopologues and isotopomers using ultrahigh-resolution traveling wave-based Structures for Lossless Ion Manipulations with serpentine ultralong path extended routing mobility spectrometry coupled to mass (SLIM SUPER IMS-MS). Mobility ions from the naturally occurring isotopic envelopes (e.g., [M], [M+1], [M+2], ... ions) showed first second peaks (i.e., [M+1] [M+2]) various tetraalkylammonium could be resolved their respective monoisotopic peak ([M]) after...
Complex samples benefit from multidimensional measurements where higher resolution enables more complete characterization of biological and environmental systems. To address this challenge, we developed a drift tube-based ion mobility spectrometry-Orbitrap mass spectrometer (IMS-Orbitrap MS) platform. circumvent the time scale disparity between fast IMS separation much slower Orbitrap MS acquisition, utilized dual gate pseudorandom sequences to multiplex injection ions allow operation in...
SARS-CoV-2 cellular infection is mediated by the heavily glycosylated spike protein. Recombinant versions of protein and receptor-binding domain (RBD) are necessary for seropositivity assays can potentially serve as vaccines against viral infection. RBD plays key roles in protein's structure function, thus, comprehensive characterization recombinant critically important biopharmaceutical applications. Liquid chromatography coupled to mass spectrometry has been widely used characterize...
We demonstrate the use of capillary zone electrophoresis with an electrokinetic sheath-flow electrospray interface coupled to a triple-quadrupole mass spectrometer for accurate and precise quantification Leu-enkephalin in complex mixture using multiple-reaction monitoring (MRM). Assay time is <6 min, no re-equilibration required between runs. A standard curve was performed presence background tryptic digest bovine albumin. reasonably reproducible peak heights (21% relative deviation),...
The unanticipated discovery of recent ultra-high-resolution ion mobility spectrometry (IMS) measurements revealing that isotopomers─compounds differ only in the isotopic substitution sites─can be separated has raised questions as to physical basis for their separation. A study comparing IMS separations two isotopomer sets conjunction with theory and simulations accounting rotational effects provides first-ever prediction rotation-mediated shifts. produce observable shifts due differences...
Diagonal capillary electrophoresis is a form of two-dimensional that employs identical separation modes in each dimension. The distal end the first incorporates an enzyme-based microreactor. Analytes are not modified by reactor will have migration times two capillaries and generate spots fall on diagonal reconstructed electropherogram. undergo enzymatic modification different second off We demonstrate system with immobilized alkaline phosphatase to monitor phosphorylation status mixture...
We report the performance of capillary zone electrophoresis coupled with an electrokinetically pumped electrospray interface and Orbitrap-Velos mass spectrometer for high sensitivity protein analysis. first investigated system quantitation tryptic digest BSA. The produced outstanding linearity respect to peak height, number peptide IDs, spectral counts across range 12 nM 750 (60 amol 3.5 fmol) BSA injected. One a detection limit 0.3 (1.5 amol) also analyzed 700 pg prepared from RAW264.7 cell...
Capillary zone electrophoresis-multiple/single reaction monitoring (CZE-MRM/SRM), which employed an electrokinetically driven sheath-flow electrospray interface, was used for the rapid and highly sensitive detection of protein analytes in complex tryptic digests. MRM channels were developed against a commercial exponential mixture bovine proteins. Five proteins spanning four orders magnitude concentration range confidently detected from only 2.5 ng digest mixture; mass limits (S/N = 3) two...
A separation voltage polarity switching transient capillary isotachophoresis (PS-tCITP) was developed to overcome a major sample loading volume limitation in (tCITP). The fundamental idea of PS-tCITP is let ions move back and forth during their initial focusing stage by the voltage, order both increase improve efficiency as compared conventional tCITP method. experimental evaluation novel method using two peptide standards at 2 μM concentration showed that maximum could be increased from 45%...
Accurate and comprehensive identification of residual glycerides in biodiesel is an important part fuel characterization due to the impact on physicochemical properties. However, analysis bound glycerol samples faces challenges lack readily available standards structurally complex glyceride species nontraditional feedstocks a risk misannotation presence impurities gas chromatographic separations. Here, we evaluate methane isobutane chemical ionization–single quadrupole mass spectrometry...