Atmospheric pressure photoionization (APPI) Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provides ultrahigh resolving power (m/Δm50% > 1,000,000 at m/z 500) and sub-ppm mass error (50 ppb) required to identify nickel porphyrin isotopes for unambiguous elemental composition assignment. We also report the first simultaneous identification and categorization of both vanadyl and nickel porphyrins in the same sample, without prior sample fractionation.
Oxalate Decarboxylase (OxDC) is an enzyme that catalyzes the manganese-dependent breakdown of the oxalate monoanion into carbon dioxide and formate. EPR measurements performed at very high magnetic fields greatly simplify the task of assigning fine structure parameters to each of the Mn(II) centers in wild-type OxDC. The results provide new insights into the strengths and limitations of theoretical methods for understanding protein-bound Mn(II), setting the stage for future EPR studies of Mn(II) centers in OxDC.
Traditional tools for routine environmental analysis and forensic chemistry of petroleum have relied almost exclusively on gas chromatography-mass spectrometry (GC-MS), although many compounds in crude oil (and its transformation products) are not chromatographically separated or amenable to GC-MS due to volatility. We apply ultrahigh resolution Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry to identify compositional changes at the molecular level between native and weathered crude oil samples and reveal enrichment in polar compounds inaccessible by GC-based characterization.
Research suggests that anisotropy in the high-symmetry coordination environment of Ni(II) complex is an order of magnitude larger than any previously known.
Pyrolysis of solid biomass, in this case pine pellets and peanut hulls, generates a hydrocarbon-rich liquid product (bio-oil) consisting of oily and aqueous phases. Here, each phase is characterized by negative-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS) to yield unique chemical formulas for thousands of compounds.
Researchers from the National High Magnetic Field Laboratory user program performed high-frequency (329 GHz) electron magnetic resonance (EMR) experiments to address questions of fundamental importance in catalysis 1) improving industrial production of ammonia and ammonia-derived fertilizers, and 2) understanding of the atmospheric nitrogen cycle.
Here, we present a powerful new approach for the analysis of saturated hydrocarbon mixtures: atmospheric pressure laser- induced acoustic desorption chemical ionization (AP/LIAD-CI) with oxygen carrier/reagent gas.
Buckminster Fullerenes ("Buckyballs") have fascinated chemists since the original discovery of C60, leading to the 1996 Nobel Prize in Chemistry for Curl, Kroto and Smalley. Although fullerenes of various sizes have since been observed, the theoretically smallest fullerene, C28, has until now escaped detection, due to its high curvature and thus high reactivity.