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Rapid Communications in Mass Spectrometry: RCM

K A Kravchenko, L S Lehnert, A S Vlaschenko, C C Voigt
RATIONALE: Isoscape origin models for mammals may be impaired by fractionation and routing of isotopes during lactation. Here, we tested if the stable carbon, nitrogen and hydrogen ratios of juvenile bats differ from those of their mothers and if derived isotopic dietary niches and geographical assignments vary accordingly between mothers and juveniles. METHODS: During the post-lactation period, we collected fur of juvenile and female common noctule bats (Nyctalus noctula) from the same maternity roost...
February 20, 2019: Rapid Communications in Mass Spectrometry: RCM
Robert Van Hale, Matthew Schofield, Mark Connor, Richard Barker, Russell Frew
RATIONALE: Stable isotope ratios can provide a 'fingerprint' to enable differentiation of sources of monofluoroacetate (MFA) hence providing a means to eliminate potential sources of MFA in a blackmail case involving the contamination of milk. METHODS: The stable isotopic composition (δ2 H, δ13 C and δ18 O values) of a library of 43 samples of MFA was determined and multivariate models constructed to differentiate samples of different composition. The data from the MFA library was compared with that obtained from MFA extracted from contaminated milk powder (the case samples)...
February 18, 2019: Rapid Communications in Mass Spectrometry: RCM
Julia L Kaszycki, Aurelio La Rotta, Benoit Colsch, François Fenaille, Claire Dauly, Anas Kamleh, Ching Wu
RATIONALE: Atmospheric pressure drift tube ion mobility is a powerful addition to the Orbitrap mass spectrometer enabling direct separation of isomers. Apart from offering high resolving power in a compact design, it also facilitates optimization of the separation gas, as shown here for a series of biologically relevant isomer pairs. METHODS: An Excellims MA3100 High Resolution Atmospheric Pressure Ion Mobility Spectrometer (HR-IMS) was coupled to a Thermo ScientificTM Q ExactiveTM Focus hybrid quadrupole-OrbitrapTM mass spectrometer, using an Excellims DirectsprayTM Electrospay Ionization source and a gas mixture setup to provide various drift gases (air, CO2 and mixtures)...
February 17, 2019: Rapid Communications in Mass Spectrometry: RCM
Guoqiang Liu, Zunjian Zhang, Xiaoqing Lv, Shuyu Zhan, Baoue Ding, Xinji Yang, Qifeng Zhu
RATIONALE: It's a long-lasting unsettled issue to discriminate between aglycone-substituted and saccharide-substituted saikosaponins by LC-MSn . It's necessary to characterize the two types of substituted saikosaponins taking into consideration their potential significant difference in bioactivity. METHODS: Taking the substituents of malonyl and acetyl as example, we developed a MS strategy to discriminate between the aglycone-substituted and saccharide-substituted saikosaponins through comparing their Y0 -nH2 O (n=1-2) ions from the protonated molecules in the full-scan mass spectra and their B ions in the MS2 spectra of sodium-adduct molecules in the positive mode...
February 16, 2019: Rapid Communications in Mass Spectrometry: RCM
Michael A Schillaci, Jessica Lintlop, Monika Sumra, Mark Pizarro, Lisa Jones-Engel
RATIONALE: Prolonged exposure to the stress hormone cortisol can precipitate a catabolic state in animals resulting in a negative nitrogen balance and increased excreted nitrogen, possibly affecting stable nitrogen and carbon isotope ratios in animal tissues. Here we test the hypothesis that stress, as measured by hair cortisol, is a significant contributor to variation in δ15 N and δ13 C values in hair. The results of the present study have important implications for the use of stable carbon and nitrogen isotope ratios measured in animal and human tissues to make inferences regarding feeding ecology and diet...
February 11, 2019: Rapid Communications in Mass Spectrometry: RCM
Shanshan Zhao, Yan Zhao, Karyne M Rogers, Ailiang Chen, Tian Zhang, Shuming Yang
RATIONALE: Isotope reference materials are essential to enable reliable and comparable isotope data across multiple laboratories. Although many reference materials already exist, the best reference materials should mimic the unknown samples, so new reference materials continue to evolve with the development of isotope research in new product areas. METHODS: Two defatted beef reference materials, CAAS-1801 and CAAS-1802, with substantially different δ13 C values (due to difference in dietary intake) have been prepared as reference materials for stable C and N isotope analysis of meat tissue...
February 10, 2019: Rapid Communications in Mass Spectrometry: RCM
Youning Ma, Mingxue Chen, Renxiang Mou, Zhaoyun Cao
RATIONALE: The presence of organotins in the environment affects food safety, making it important to monitor the levels of organotin pesticides (OTPs) in fruit and vegetable samples. METHODS: In the present study, a simple and low cost method for simultaneous determination of three OTPs (azocyclotin, fenbutatin oxide and triphenyltin hydroxide) in vegetable and fruit samples was developed and validated, based on solid-phase extraction and liquid chromatography-tandem mass spectrometry...
February 8, 2019: Rapid Communications in Mass Spectrometry: RCM
Elizabeth D Hetherington, Carolyn M Kurle, Mark D Ohman, Brian N Popp
RATIONALE: It is imperative to understand how chemical preservation alters tissue isotopic compositions before using historical samples in ecological studies. Specifically, although compound-specific isotope analysis of amino acids (CSIA-AA) is becoming a widely-used tool, there is little information on how preservation techniques affect amino acid δ15 N values. METHODS: We evaluated the effects of chemical preservatives on bulk tissue δ13 C and δ15 N and amino acid δ15 N values, measured by GC/IRMS, of a) tuna (Thunnus albacares) and squid (Dosidicus gigas) muscle tissues that were fixed in formaldehyde and stored in ethanol for two years and b) two copepod species, Calanus pacificus and Eucalanus californicus, which were preserved in formaldehyde for 24-25 years...
February 7, 2019: Rapid Communications in Mass Spectrometry: RCM
Luis E Sojo, Rainbow Kwan, Cathy Dang, Matthew Tung, Jenny Li
RATIONAL: Nav 1.6 is a transmembrane voltage gated sodium channel implicated in various forms of epilepsy. Modulation of its activity in epilepsy animal models can be accomplished using inhibitors which may result in changes in its expression. There is a need to generate reliable quantitative measurements of Nav 1.6 expression in animal models. This research explores the feasibility of quantifying Nav 1.6 expression in mouse brains using targeted multiple reaction monitoring mass spectrometry...
February 6, 2019: Rapid Communications in Mass Spectrometry: RCM
Kyle Mason-Jones, Callum C Banfield, Michaela A Dippold
RATIONALE: Many bacteria synthesize carbon (C) and energy storage compounds, including water-insoluble polyester lipids composed mainly or entirely of poly(3-hydroxybutyrate) (PHB). Despite the potential significance of C and energy storage for microbial life and C cycling, few measurements of PHB in soil have been reported. METHODS: A new protocol was implemented, based on an earlier sediment extraction and derivatization procedure, with quantification by gas chromatography-mass spectrometry (GC/MS) and 13 C isotopic analysis by GC-combustion-isotope ratio mass spectrometry (GC/C/IRMS)...
February 4, 2019: Rapid Communications in Mass Spectrometry: RCM
Amber S Bowman, Shardrack O Asare, Bert C Lynn
RATIONALE: Effective analytical techniques are needed to characterize lignin products for the generation of renewable carbon sources. Application of matrix-assisted laser desorption/ionization (MALDI) in lignin analysis is limited because of poor ionization efficiency. In this study, we explored the potential of cationization along with a 2,5-dihydroxyacetophenone (DHAP) matrix to characterize model lignin oligomers. METHODS: Synthesized lignin oligomers were analyzed using the developed MALDI method...
February 4, 2019: Rapid Communications in Mass Spectrometry: RCM
Zhi Liu, Yuwei Yuan, Yongzhi Zhang, Yuanzhi Shi, Guixian Hu, Jiahong Zhu, Karyne M Rogers
RATIONALE: Deliberate and fraudulent origin mislabeling of Chinese green tea motivated by large price differences often brings significant food safety risks and damages consumer trust. Currently there is no reliable method to verify the origin of green tea produced in China. Stable isotope and multi-element analyses combined with statistical models are widely-acknowledged as useful traceability techniques for many agro-products, and could be developed to confirm the geographical origin of Chinese green tea and more importantly, combat illegal green tea mislabeling and fraud...
February 4, 2019: Rapid Communications in Mass Spectrometry: RCM
Lukáš Pečinka, Lubomír Prokeš, Josef Havel
RATIONALE: Gallium-selenide thin films important for electronics and phase-change materials are prepared via pulsed laser deposition (PLD); however, there are no studies concerning the analysis of gallium-selenide clusters formed in the gas phase. Laser desorption ionisation (LDI) combined with time-of-flight mass spectrometry (TOF MS) has the high potential to generate charged Gam Sen clusters, to analyse them and thus to develop new materials METHODS: LDI of Ga-Se mixtures using a pulsed laser (337 nm nitrogen) was used to generate gallium-selenide clusters...
February 2, 2019: Rapid Communications in Mass Spectrometry: RCM
Dongwan Lim, Yunjae Park, Rakwoo Chang, Arif Ahmed, Sunghwan Kim
RATIONALE: Molecular dynamics (MD) simulations with finite temperature were performed to improve the theoretical prediction of collisional cross section (CCS) values, especially for aromatic compounds containing long alkyl chains. METHODS: In this study, the CCS values of 11 aromatic compounds with long alkyl chains were calculated by MD simulation while considering internal energy at 300, 500, and 700 K, and the results were compared with experimentally determined values...
February 1, 2019: Rapid Communications in Mass Spectrometry: RCM
Lucie Tsamba, Olivier Correc, Pierre Le Cloirec, Nicolas Cimetière
RATIONALE: Chlorine reacts in swimming pools with several compounds released by bathers to form disinfection by-products (DBPs). Epidemiological studies have shown adverse effects on health associated with the exposure to DBPs present in indoor swimming pool atmosphere. DBPs analyses require the use of multiple techniques depending on the targeted molecules. The measurement process itself is challenging due to the low stability of several compounds and the lack of specificity of certain methods...
February 1, 2019: Rapid Communications in Mass Spectrometry: RCM
Jean-François Rontani, Claude Aubert
No abstract text is available yet for this article.
February 1, 2019: Rapid Communications in Mass Spectrometry: RCM
John F J Todd, Raymond E March
Upon the death of Peter H. Dawson in 2015, mass spectrometry lost a major figure. Within the area of radiofrequency quadrupole electric fields applied to mass spectrometry, Dawson stands alongside its pioneers Wolfgang Paul, Nobelist and inventor of the technology, and Wilson Brubaker, who identified and overcame the deleterious effects of fringing electric fields on quadrupole mass filter performance. Seventy-one of Dawson's 97 scientific publications are concerned with quadrupole mass analyzers, ion traps and monopole mass spectrometers...
February 1, 2019: Rapid Communications in Mass Spectrometry: RCM
J Cole, E J Hanson, D C James, D H Dockrell, M J Dickman
RATIONALE: Histone PTMs play key roles in regulating eukaryotic gene expression. Mass spectrometry (MS) has emerged as a powerful method to characterize and quantify histone PTMs as it allows unbiased identification and quantification of multiple histone PTMs including combinations of the modifications present. METHODS: In this study we compared a range of data acquisition methods for the identification and quantification of the histone PTMs using a Q Exactive HF Orbitrap...
January 30, 2019: Rapid Communications in Mass Spectrometry: RCM
Arunan Suganya, Debal Deb, Thalappil Pradeep
RATIONALE: Documentation of the metabolite profile of rice landraces is essential as most of them are lost due to the conventional practices of cultivation. Therefore, application of mass spectrometry imaging will be an appropriate analytical platform for molecular profiling, as it aids in a detailed understanding of the site-specific localization patterns of biomolecules, and the cues concerning metabolic pathways in organisms. METHODS: Desorption electrospray ionization mass spectrometry (DESI MS), a relatively non-destructive analytical technique for surface sampling in natural conditions...
January 30, 2019: Rapid Communications in Mass Spectrometry: RCM
Linda M Reynard, Saskia E Ryan, Noreen Tuross
RATIONALE: Different thermal conversion reactor packings result in distinct δ2 H values in nitrogen-containing materials, such as bone collagen. An older 'traditional' glassy carbon packing method causes incomplete conversion of N-containing samples to H2 gas, resulting in altered δ2 H values compared with the complete conversion of hydrogen obtained with a chromium packed reactor. Given that δ2 H values from collagen are gaining importance in palaeoecological and archaeological studies, a determination of the relationship between δ2 H values produced with a glassy carbon-packed and a chromium-packed reactor is needed...
January 25, 2019: Rapid Communications in Mass Spectrometry: RCM
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