Han M.-G.,Brookhaven National Laboratory |
Zhu Y.,Brookhaven National Laboratory |
Wu L.,Brookhaven National Laboratory |
Aoki T.,JEOL United States Inc. |
And 5 more authors.
Advanced Materials | Year: 2013
Field-induced switching of ferroelectric domains with a topological vortex configuration is studied by atomic imaging and electrical biasing in an electron microscope, revealing the role of topological defects on the topologically-guided change of domain-wall pairs in a hexagonal manganite. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Kubo A.,JEOL Ltd. |
Satoh T.,JEOL Ltd. |
Itoh Y.,JEOL Ltd. |
Hashimoto M.,JEOL Ltd. |
And 2 more authors.
Journal of the American Society for Mass Spectrometry | Year: 2013
A new MALDI-TOF/TOF system with monoisotopic precursor selection was applied to the analysis of triacylglycerols in an olive oil sample. Monoisotopic precursor selection made it possible to obtain product-ion mass spectra without interference from species that differed by a single double bond. Complete structure determination of all triacylglycerols, including structural isomers, was made possible by interpreting the charge-remote fragmentation resulting from high-energy collision-induced dissociation (CID) of the sodiated triacylglycerols. [Figure not available: see fulltext.] © 2012 The Author(s).
Jeol United States Inc. | Date: 2010-05-17
A method of producing analyte, analyte fragment, and/or analyte adduct ions for mass analysis comprises the steps of spraying a solvent at a surface bearing the analyte, directing desorbed analyte evolved from the surface into a region containing species which will ionize the analyte on collision, the ionizing region not including the surface bearing the analyte, and directing the ions formed in the ionizing region to the entrance to a mass analyzer.
Cody R.B.,JEOL United States Inc. |
Dane A.J.,JEOL United States Inc. |
Dawson-Andoh B.,West Virginia University |
Adedipe E.O.,Colorado State University |
Nkansah K.,West Virginia University
Journal of Analytical and Applied Pyrolysis | Year: 2012
Thirty-four samples of Red Oak (Quercus rubra) and fifty samples of White Oak (Quercus alba) were analyzed by pyrolytic direct analysis in real time (DART) ionization coupled with time-of-flight (TOF) mass spectrometry. Although significant differences were not observed in the positive-ion mass spectra, the negative-ion mass spectra showed clear differences. Principal component analysis (PCA) and linear discriminant analysis (LDA) were calculated for the relative abundances of 11 peaks in the negative-ion mass spectra including peaks tentatively assigned as representing deprotonated acetic, malic, gallic, dimethoxycinnamic, and ellagic acids. Leave one out cross validation (LOOCV) was 100% successful in classifying the samples for both PCA and LDA. © 2012 Elsevier B.V. All rights reserved.
Applications of direct analysis in real time mass spectrometry (DART-MS) in allium chemistry. 2-propenesulfenic and 2-propenesulfinic acids, diallyl trisulfane S -oxide, and other reactive sulfur compounds from crushed garlic and other alliums
Block E.,University at Albany |
Dane A.J.,JEOL United States Inc. |
Thomas S.,University at Albany |
Cody R.B.,JEOL United States Inc.
Journal of Agricultural and Food Chemistry | Year: 2010
Through the use of direct analysis in real time mass spectrometry (DART-MS), 2-propenesulfenic acid, an intermediate long postulated as being formed when garlic (Allium sativum) is crushed, has been detected for the first time and determined by mass spectrometric methods to have a half-life of <1 s at room temperature. Two other key intermediates, 2-propenesulfinic acid and diallyl trisulfane S-oxide, have also been detected for the first time in volatiles from crushed garlic, along with allicin and related thiosulfinates, allyl alcohol, sulfur dioxide, propene, and pyruvate as coproducts. A commercial dietary supplement containing garlic powder, which was sampled after crushing, was found to contain alliin, methiin, and S-allylcysteine and produced allicin upon addition of water. DART-MS detection of 1-butenesulfenic acid from the ornamental A. siculum is also reported. (Z)-Propanethial S-oxide (onion lachrymatory factor), absent in garlic, is found to be formed from crushed elephant garlic (Allium ampeloprasum), consistent with the classification of this plant as a closer relative of leek than of garlic. Mixtures of thiosulfinates, lachrymatory thial S-oxides, and related compounds are directly observed from crushed leek (Allium porrum) and Chinese chive (Allium tuberosum). Disulfanes and polysulfanes are detected only when the Allium samples are heated, consistent with earlier conclusions that these are not primary products from cut or crushed alliums. © 2010 American Chemical Society.