A5040752970- Mass Spectrometry Techniques and Applications
- Analytical Chemistry and Chromatography
- Pharmaceutical Quality and Counterfeiting
- Analytical chemistry methods development
- Petroleum Processing and Analysis
- Pesticide Residue Analysis and Safety
- Hydrocarbon exploration and reservoir analysis
- Malaria Research and Control
- Identification and Quantification in Food
- Pharmaceutical Economics and Policy
- Advanced Proteomics Techniques and Applications
- Forensic Toxicology and Drug Analysis
- Marine Biology and Environmental Chemistry
- Metabolomics and Mass Spectrometry Studies
- Ion-surface interactions and analysis
- Fullerene Chemistry and Applications
- Graphene research and applications
- Advanced Chemical Sensor Technologies
- Thermochemical Biomass Conversion Processes
- Isotope Analysis in Ecology
- Air Quality and Health Impacts
- Cybercrime and Law Enforcement Studies
- Vehicle emissions and performance
- Atmospheric chemistry and aerosols
- Marine Biology and Ecology Research
Phillips 66 (United States)
2017-2021
Florida State University
2011-2014
National High Magnetic Field Laboratory
2011-2014
Georgia Institute of Technology
2006-2011
Louisiana State University
2010
Université Toulouse III - Paul Sabatier
2009
Centre National de la Recherche Scientifique
2009
Centers for Disease Control and Prevention
2008
National Center for Infectious Diseases
2007
Georgia Tech Research Institute
2007
Ambient ionization techniques enable the interrogation of a variety samples in their native state by mass spectrometry, and are rapidly advancing all fields where screening for presence various analytes broadband and/or high-throughput fashion is desirable. This Highlight article provides an introduction to field, showcases different approaches reported since 2004, with emphasis on most recent developments.
Organism surfaces represent signaling sites for attraction of allies and defense against enemies. However, our understanding these signals has been impeded by methodological limitations that have precluded direct fine-scale evaluation compounds on native surfaces. Here, we asked whether natural products from the red macroalga Callophycus serratus act in surface-mediated pathogenic microbes. Bromophycolides callophycoic acids algal extracts inhibited growth Lindra thalassiae, a marine fungal...
Background Since 1998 the serious public health problem in South East Asia of counterfeit artesunate, containing no or subtherapeutic amounts active antimalarial ingredient, has led to deaths from untreated malaria, reduced confidence this vital drug, large economic losses for legitimate manufacturers, and concerns that artemisinin resistance might be engendered. Methods Findings With evidence a deteriorating situation, group police, criminal analysts, chemists, palynologists, workers...
Twenty-five years ago, Boduszynski et al. conducted a comprehensive study of heavy oil composition and concluded that crude increases gradually continuously with regard to aromaticity, molecular weight, heteroatom content from the light distillates non-distillables (the continuum model). Previous exhaustive characterization vacuum gas by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provided compositional data strongly supports model. However, when formulas obtained...
Plasmodium falciparum malaria remains a major public health problem. A vital component of control rests on the availability good quality artemisinin-derivative based combination therapy (ACT) at correct dose. However, there are increasing reports poor anti-malarials in Africa. Seven collections artemisinin derivative monotherapies, ACT and halofantrine suspicious were collected 2002/10 eleven African countries Asia en route to Packaging, chemical composition (high performance liquid...
Desorption electrospray ionization mass spectrometry (DESI MS) is rapidly becoming accepted as a powerful surface characterization tool for wide variety of samples in the open air. Besides its well-established high-throughput capabilities, unique feature DESI that chemical reactions between charged spray microdroplets and molecules can be exploited to enhance ionization. Here, we present rapid screening assay artesunate antimalarials based on reactive DESI. Artesunate vital therapy...
During the past decade, there has been a marked increase in number of reported cases involving counterfeit medicines developing and developed countries. Particularly, artesunate-based antimalarial drugs have targeted, because their high demand cost. Counterfeit antimalarials can cause death contribute to growing problem drug resistance, particularly southeast Asia. In this study, complementarity two-dimensional diffusion-ordered (1)H nuclear magnetic resonance spectroscopy (2D DOSY NMR) with...
We present a new method for molecular characterization of intact biochar directly, without sample preparation or pretreatment, on the basis desorption atmospheric pressure photoionization (DAPPI) coupled to Fourier transform ion cyclotron resonance (FTICR) mass spectrometry. Conventional ionization methods (e.g., electrospray photoionization) natural organic matter have limited utility chars due incomplete solubility in common solvents. Therefore, direct techniques that do not require...
We report the first coupling of a desorption electrospray ionization (DESI) ion source to Fourier transform cyclotron resonance mass spectrometry (ESI-FT-ICR-MS) for high-resolution protein analysis. The DESI FT-ICR-MS design is described in detail along with preliminary data obtained on peptides and proteins ranging from 1 5.7 kDa.
The direct quantitation of active ingredients in solid pharmaceutical tablets by desorption electrospray ionization mass spectrometry (DESI MS) is complicated the dependence DESI signal on variables such as spray angles and distances, morphological sample properties, difficulty properly incorporating an internal standard. Here, a MS method for quantitative screening widely counterfeited antimalarial containing artesunate presented. This based reactive DESI, where analyte occur formation...
Abstract Background Counterfeit oral artesunate has been a major public health problem in mainland SE Asia, impeding malaria control. A countrywide stratified random survey was performed to determine the availability and quality of pharmacies outlets (shops selling medicines) Lao PDR (Laos). Methods In 2003, 'mystery' shoppers were asked buy tablets from 180 12 18 provinces. Outlets selected using sampling by investigators not involved sampling. Samples analysed for packaging...
Presented here is a novel multimode ambient ion source termed desorption electrospray/metastable-induced ionization (DEMI), which integrates the benefits and circumvents some of limitations electrospray (DESI, polarity range limited) direct analysis in real time (DART)-type metastable-induced chemical (MICI, molecular weight limited). This allows three unique operation modes, each with capabilities, including spray (DESI-like)-only, MICI-only, DEMI (multimode), can be thus operated these...
We present atmospheric pressure laser-induced acoustic desorption chemical ionization (AP/LIAD-CI) with O(2) carrier/reagent gas as a powerful new approach for the analysis of saturated hydrocarbon mixtures. Nonthermal sample vaporization subsequent generates abundant ion signals straight-chain, branched, and cycloalkanes minimal or no fragmentation. [M - H](+) is dominant species straight-chain branched alkanes. For cycloalkanes, M(+•) dominate mass spectrum at lower capillary temperature...
We present a novel nonresonant laser-based matrix-free atmospheric pressure ionization technique, laser-induced acoustic desorption chemical (AP/LIAD-CI). The technique decouples analyte from subsequent by reagent ions generated corona discharge initiated in ambient air or the presence of vaporized toluene as CI dopant at room temperature. Analyte is shock wave induced titanium foil coated with electrosprayed sample, irradiated rear side high-energy laser pulses. enables facile and...
This work introduces a novel approach by use of high-energy collision-induced dissociation for fragmenting asphaltenes into their constituent stable aromatic cores as means determining the relative proportions island-to-archipelago structures. is particularly useful comparing from various crude oils. Ion generation was performed atmospheric pressure photoionization, which has been demonstrated to provide hydrogen-to-carbon ratios consistent with bulk measurements combustion analysis less...
We describe an adult with uncomplicated Plasmodium falciparum malaria who did not improve clinically despite 5 days of intramuscular artemether therapy. He was prescribed a lower dose (kg body weight) than that recommended, and vial from the packet contained only 74% as stated by manufacturer. The combination underdosing, poor-quality drug, intrinsic low bioavailability may have contributed to his poor clinical response. Analysis packaging chemical "fingerprinting" suggested drug genuine but...
Competitive host–guest chemistry on a desorption electrospray ionization mass spectrometry (DESI MS) platform is presented here as the basis for rapid and quantitative screening method assessing quality of Tamiflu®capsules with minimal sample preparation. Oseltamivir, active ingredient in Tamiflu®, an orally neuraminidase inhibitor antiviral. The high cost demand this drug has made it target counterfeiters, reports counterfeit have already appeared. This urges development sensitive tools...
In this work, we investigate the molecular composition and nanostructure of gasification charcoal (biochar) by comparing it with heat-treated fullerene arc-soot. Using ultrahigh resolution Fourier transform ion-cyclotron resonance laser desorption ionization time-of-flight mass spectrometry, Raman spectroscopy, high transmission electron microscopy analyzed low tar content obtained from gasification. Mass spectrometry revealed no magic number fullerenes such as C60 or C70 in charcoal. The...
We present the first coupling of laser spray ionization inlet (LSII) and matrix assisted (MAII) to high-field Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) for generation electrospray-like ions take advantage increased sensitivity, range, resolving power afforded by multiple charging. apply technique top-down protein analysis characterization metalloproteins. also a novel method multiply-charged copper-peptide complexes with varying degrees copper adduction LSII....
The new Waxphaltene Determinator method is based on the on-column precipitation and redissolution separation technique developed at Western Research Institute. Although high-performance liquid chromatography (HPLC) instrumentation detectors are used, does not involve chromatographic interaction between material being separated stationary phase. It freezing, melting, solubility. uses methyl ethyl ketone −24 °C to precipitate waxes asphaltenes. precipitated redissolved in four steps using a...