8,430 results match your criteria Rapid Communications in Mass Spectrometry[Journal]


Hair cortisol and stable carbon and nitrogen isotope ratios in Barbary macaques (Macaca sylvanus) from Gibraltar.

Rapid Commun Mass Spectrom 2019 Feb 11. Epub 2019 Feb 11.

Department of Anthropology, University of Washington, Box 353100, Seattle, WA, 98105, USA.

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 δ N and δ 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. Read More

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http://dx.doi.org/10.1002/rcm.8413DOI Listing
February 2019

Two new defatted beef reference materials CAAS-1801, CAAS-1802 for carbon and nitrogen stable isotope-ratio measurements.

Rapid Commun Mass Spectrom 2019 Feb 10. Epub 2019 Feb 10.

Institute of Quality Standard & Testing Technology for Agro-Products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.

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 δ C values (due to difference in dietary intake) have been prepared as reference materials for stable C and N isotope analysis of meat tissue. Read More

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http://doi.wiley.com/10.1002/rcm.8411
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http://dx.doi.org/10.1002/rcm.8411DOI Listing
February 2019
2 Reads

Simultaneous determination of three organotin pesticides in fruits and vegetables by high-performance liquid chromatography-tandem mass spectrometry.

Rapid Commun Mass Spectrom 2019 Feb 8. Epub 2019 Feb 8.

China National Rice Research Institute, Hangzhou, 311400.

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.

Results: Extraction with acetonitrile containing 0. Read More

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http://dx.doi.org/10.1002/rcm.8409DOI Listing
February 2019

Effects of chemical preservation on bulk and amino acid isotope ratios of zooplankton, fish, and squid tissues.

Rapid Commun Mass Spectrom 2019 Feb 7. Epub 2019 Feb 7.

Department of Geology and Geophysics, University of Hawaii, Honolulu, HI, USA.

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 δ N values.

Methods: We evaluated the effects of chemical preservatives on bulk tissue δ C and δ N and amino acid δ 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. Read More

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http://doi.wiley.com/10.1002/rcm.8408
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http://dx.doi.org/10.1002/rcm.8408DOI Listing
February 2019
2 Reads

On the Feasibility of Quantifying Sodium Channel Na 1.6 Protein in Mouse Brain using targeted UHPLC-ESI- MRM Mass Spectrometry.

Rapid Commun Mass Spectrom 2019 Feb 6. Epub 2019 Feb 6.

Compound Properties Group, Xenon Pharmaceuticals Inc., 3650 Gilmore Way, Burnaby, British Columbia, V5G 4W8, Canada.

Rational: Na 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. Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1002/rcm.8398
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http://dx.doi.org/10.1002/rcm.8398DOI Listing
February 2019
9 Reads

Compound-specific C SIP confirms synthesis of polyhydroxybutyrate by soil bacteria.

Rapid Commun Mass Spectrom 2019 Feb 4. Epub 2019 Feb 4.

Biogeochemistry of Agroecosystems, University of Goettingen, Büsgenweg 2, 37077, Goettingen, Germany.

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 C isotopic analysis by GC-combustion-isotope ratio mass spectrometry (GC/C/IRMS). Read More

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https://onlinelibrary.wiley.com/doi/abs/10.1002/rcm.8407
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http://dx.doi.org/10.1002/rcm.8407DOI Listing
February 2019
4 Reads

MALDI-TOF-MS Analysis for Characterization of Lignin Oligomers Using Cationization Techniques and DHAP Matrix.

Rapid Commun Mass Spectrom 2019 Feb 4. Epub 2019 Feb 4.

Department of Chemistry, University of Kentucky, Lexington, KY, 40506, USA.

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. Read More

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http://dx.doi.org/10.1002/rcm.8406DOI Listing
February 2019
1 Read

Geographical traceability of Chinese green tea using stable isotope and multi-element chemometrics.

Rapid Commun Mass Spectrom 2019 Feb 4. Epub 2019 Feb 4.

Institute of Quality and Standards for Agricultural Products, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.

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. Read More

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http://dx.doi.org/10.1002/rcm.8405DOI Listing
February 2019
1 Read

Gallium selenide clusters generated via laser desorption ionisation quadrupole ion trap time-of-flight mass spectrometry.

Rapid Commun Mass Spectrom 2019 Feb 2. Epub 2019 Feb 2.

Department of Chemistry, Faculty of Science, Kamenice 5, 625 00, Brno, Czech Republic.

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 Ga Se 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. Mass spectra were recorded (in positive and negative ion mode) on a TOF mass spectrometer equipped with a quadrupole ion trap and reflectron mass analyser. Read More

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http://dx.doi.org/10.1002/rcm.8403DOI Listing
February 2019

Application of Molecular Dynamics Simulation to Improve the Theoretical Prediction for Collisional Cross Section of Aromatic Compounds with Long Alkyl Chains in Crude Oils.

Rapid Commun Mass Spectrom 2019 Feb 1. Epub 2019 Feb 1.

Department of Chemistry, Kyungpook National University, Daegu, 41566, Republic of Korea.

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.

Results: The CCS values calculated at higher energies showed better agreement with the experimental values. Read More

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http://dx.doi.org/10.1002/rcm.8400DOI Listing
February 2019

Analysis of chlorination by-products in swimming pool water by membrane introduction mass spectrometry - influence of water physicochemical parameters.

Rapid Commun Mass Spectrom 2019 Feb 1. Epub 2019 Feb 1.

CNRS, UMR 6226, Ecole Nationale Supérieure de Chimie de Rennes, 11 allée de Beaulieu, CS 50837, 35708 Rennes Cedex 7, France.

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. Read More

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http://dx.doi.org/10.1002/rcm.8399DOI Listing
February 2019

Unexpected peaks in EI mass spectra of trimethylsilyl derivatives resulting from the presence of trace amounts of water and oxygen in GC/QTOF systems.

Rapid Commun Mass Spectrom 2019 Feb 1. Epub 2019 Feb 1.

Laboratoire de Pharmacocinétique et Toxicocinétique (EA 3286), Faculté de Pharmacie, 13385, Marseille, France.

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http://dx.doi.org/10.1002/rcm.8404DOI Listing
February 2019

AN APPRECIATION OF THE SCIENTIFIC RESEARCHES OF Dr PETER H. DAWSON.

Rapid Commun Mass Spectrom 2019 Feb 1. Epub 2019 Feb 1.

Department of Chemistry, Trent University, Peterborough, Ontario, K9L 0G2, Canada.

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. Read More

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http://doi.wiley.com/10.1002/rcm.8402
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http://dx.doi.org/10.1002/rcm.8402DOI Listing
February 2019
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Comparison of data acquisition methods for the identification and quantification of histone post-translational modifications on a Q Exactive HF hybrid quadrupole Orbitrap mass spectrometer.

Rapid Commun Mass Spectrom 2019 Jan 30. Epub 2019 Jan 30.

Department of Chemical and Biological Engineering, University of Sheffield, UK.

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. Read More

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http://dx.doi.org/10.1002/rcm.8401DOI Listing
January 2019

Spatial distribution mapping of molecules in the grains of different rice landraces, using desorption electrospray ionization mass spectrometry.

Rapid Commun Mass Spectrom 2019 Jan 30. Epub 2019 Jan 30.

DST Unit of Nanoscience, and Thematic Unit of Excellence, Department of Chemistry, Indian Institute of Technology Madras, Chennai, 600 036, India.

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. Read More

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http://dx.doi.org/10.1002/rcm.8397DOI Listing
January 2019

The interconversion of δ H values of collagen between thermal conversion reactor configurations.

Rapid Commun Mass Spectrom 2019 Jan 25. Epub 2019 Jan 25.

Department of Human Evolutionary Biology, Harvard University, 11 Divinity Avenue, Cambridge, MA, USA, 02138.

Rationale: Different thermal conversion reactor packings result in distinct δ 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 H gas, resulting in altered δ H values compared with the complete conversion of hydrogen obtained with a chromium packed reactor. Given that δ H values from collagen are gaining importance in palaeoecological and archaeological studies, a determination of the relationship between δ H values produced with a glassy carbon-packed and a chromium-packed reactor is needed. Read More

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http://dx.doi.org/10.1002/rcm.8396DOI Listing
January 2019
1 Read

Towards the use of ion mobility mass spectrometry-derived collision cross section as a screening approach for unambiguous identification of targeted pesticides in food.

Rapid Commun Mass Spectrom 2019 Jan 24. Epub 2019 Jan 24.

MolSys Research Unit, Laboratory of Mass Spectrometry, University of Liège, 3 Allée de la chimie B6C, Liège, Belgium.

Rationale: Mass Spectrometry (MS) is the reference method for the screening of ultra-trace residues of pesticides in food because MS offers the required selectivity/sensitivity to gather information and enable the analyst to make informed decisions during the identification process. Here we present and discuss the use of collision cross section (CCS) values in addition to mass accuracy and retention times in a pesticide screening method that integrates all the features offered by coupling UPLC with IMS-MS.

Methods: All experiments were carried out using UHPLC coupled to a travelling wave ion mobility mass spectrometer equipped with an ESI source working in positive mode. Read More

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http://dx.doi.org/10.1002/rcm.8395DOI Listing
January 2019
2 Reads

Calibration of δ O and O values of three international standards: IAEA-603, NBS19 and NBS18.

Rapid Commun Mass Spectrom 2019 Jan 24. Epub 2019 Jan 24.

Institute of Earth Sciences, Hebrew University of Jerusalem, Israel.

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http://dx.doi.org/10.1002/rcm.8391DOI Listing
January 2019
1 Read

Tandem mass spectrometry characterization of a conjugate between oleuropein and hydrated cis-diammineplatinum (II).

Rapid Commun Mass Spectrom 2019 Jan 23. Epub 2019 Jan 23.

Dipartimento di Chimica, Università degli Studi di Bari Aldo Moro, via Orabona 4, 70126, Bari, Italy.

Rationale: Oleuropein (Ole) has been claimed to mitigate cisplatin (CP) induced acute injury in kidney and liver of mice. In-vitro reactivity of hydrated CP species with Ole, and Ole metabolite hydroxytyrosol (HT) is of great interest as the preliminary step for gathering in-vivo information on the possible physiological role of the Ole/HT-cis-diammineplatinum (II) (Ole/HT-cis-DAP) conjugate.

Methods: Reversed-phase liquid chromatography coupled to electrospray ionization and mass spectrometry using a linear-ion trap instrument (RPLC-ESI-MS) and tandem mass (MS/MS) measurements, both in positive and negative ion mode, revealed the molecular identity of platinum-based conjugates. Read More

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http://dx.doi.org/10.1002/rcm.8394DOI Listing
January 2019
1 Read

Impact of freezing and ethanol preservation techniques on the stable isotope analysis of humpback whale (Megaptera novaeangliae) skin.

Rapid Commun Mass Spectrom 2019 Jan 23. Epub 2019 Jan 23.

Departamento de Ciencias Marinas y Costeras, Universidad Autónoma de Baja California Sur, Carretera al Sur KM 5.5, C.P, 23080, La Paz, Baja California Sur, México.

Rationale: Distinct techniques employed to preserve different types of tissues may affect stable isotope analyses conducted on samples, and this is critical when field work takes place in remote areas. To investigate this, the stable isotope ratios (δ C and δ N values) obtained using two methods commonly used to preserve humpback whale (and other cetaceans) skin samples were compared.

Methods: A total of 54 pairs of skin samples of humpback whales from the southern Baja California Peninsula, Mexico, were preserved in ethanol (90%) and by freezing, between 2007 and 2009. Read More

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http://dx.doi.org/10.1002/rcm.8392DOI Listing
January 2019
4 Reads

The influence of diet composition and tissue type on the stable isotope incorporation patterns of a small bodied southern African minnow Enteromius anoplus (Cypriniformes, Cyprinidae).

Rapid Commun Mass Spectrom 2019 Jan 23. Epub 2019 Jan 23.

Department of Ichthyology and Fisheries Science, Rhodes University, PO Box 94, Grahamstown, 6140, South Africa.

Rationale: In trophic ecology, the use of stable isotope data relies on the general understanding of isotope turnover rates and diet-to-tissue discrimination factors (DTDFs). Recent studies on the application of stable isotope data have shown that isotope turnover rates and DTDFs can be influenced by many factors, including diet composition and tissue type. This study investigated the influence of diet composition and tissue type on stable isotope incorporation patterns in a small bodied African minnow, the chubbyhead barb Enteromius anoplus. Read More

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http://dx.doi.org/10.1002/rcm.8393DOI Listing
January 2019
1 Read

An automated laser fluorination technique for high precision analysis of three oxygen isotopes in silicates.

Rapid Commun Mass Spectrom 2019 Jan 22. Epub 2019 Jan 22.

Division of Earth-System Sciences, Korea Polar Research Institute, Incheon, 21990, Republic of Korea.

Rationale: The three oxygen isotopes in terrestrial/extraterrestrial silicates can provide geochemical and cosmochemical information about their origin and secondary processes that result from isotopic exchange. A laser fluorination technique has been widely used to extract oxygen from silicates for δ O and δ O measurements by isotope ratio mass spectrometry. Continued improvement of the techniques is still important for high precision measurement of oxygen isotopic ratios. Read More

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http://dx.doi.org/10.1002/rcm.8389DOI Listing
January 2019
1 Read

The role of fluoroalcohols as counter anion for ion-pair reversed-phase liquid chromatography/high resolution electrospray ionization mass spectrometry analysis of oligonucleotides.

Rapid Commun Mass Spectrom 2019 Jan 22. Epub 2019 Jan 22.

Joint Laboratory for Translational Cancer Research of Chinese Medicine of the Ministry of Education of the People's Republic of China, Guangzhou University of Chinese Medicine, Guangzhou, Guangdong Province, 510006, PR China.

Rationale: Hexafluoroisopropanol (HFIP) has been widely used as a counter anion in mobile phase for ion-pairing reversed-phase liquid chromatography/mass spectrometry (IP-RP LC/MS) analysis of oligonucleotides. However, researchers are still searching for improvements to counter anions for LC/MS analysis of oligonucleotides. This study aimed to find alternatives to HFIP for analyzing oligonucleotides. Read More

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http://dx.doi.org/10.1002/rcm.8386DOI Listing
January 2019
1 Read

Alternative Mass Spectrometry Techniques for the Validation of Fragmentation Pattern of Capsaicin and Dihydrocapsaicin.

Rapid Commun Mass Spectrom 2019 Jan 22. Epub 2019 Jan 22.

Instituto de Química, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Coyoacán, D. F., 04510, México.

Rationale: Capsaicinoids are prevalent secondary metabolites in many natural and synthetic pharmacological compounds. To date, several soft ionization studies related to capsaicinoids have been reported; they all proposed a common fragmentation pattern based on a rearrangement of the aromatic double bonds and the fragmentation of the various positional acyl chains. However, the mechanism has never been validated by high resolution analyses. Read More

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http://dx.doi.org/10.1002/rcm.8388DOI Listing
January 2019
1 Read

Influence of leaf age, species and soil depth on the authenticity and geographical origin assignment of green tea.

Rapid Commun Mass Spectrom 2019 Jan 22. Epub 2019 Jan 22.

National Isotope Centre, GNS Science, 30 Gracefield Road, Lower Hutt, 5040, New Zealand.

Rationale: Stable isotope fractionation occurring during leaf growth provides internal characteristics for identifying the geographical origin, traceability and authentication of tea. Studying the influence of leaf age, species and the relationship with the cultivated soil may reveal previously undocumented stable isotope fractionation mechanisms, and provide a deeper understanding of the physiological isotopic effects on the tractability and authentication accuracy of green tea to combat its mislabeling and fraudulent conducts.

Methods: 36 pairs of young (one bud with one leaf) and mature growth (older leaf) samples from two species of Longjing tea (Longjing #43 and Colonial cultivar) and corresponding cultivation soil samples from two different depth layers (0-20 cm and 20-40 cm) were collected in Westlake district, Hangzhou, Zhejiang province, China. Read More

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http://doi.wiley.com/10.1002/rcm.8387
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http://dx.doi.org/10.1002/rcm.8387DOI Listing
January 2019
4 Reads

Enantiomeric analysis of polycyclic musks AHTN and HHCB and HHCB-lactone in sewage sludge by gas chromatography-tandem mass spectrometry.

Rapid Commun Mass Spectrom 2019 Jan 22. Epub 2019 Jan 22.

State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment Protection and Resource Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

Rationale: Enantioselective analysis of chiral compounds is an interesting and challenging technique used to elucidate the degradation/transformation mechanisms of these compounds or understand their environmental processes. In this study, we have developed an effective separation and detection approach for the enantiomeric analysis of AHTN and HHCB, as well as a transformation product of HHCB (HHCB-lactone), in sludge samples.

Methods: The analytical method was developed using a cyclodextrin-based enantioselective gas chromatography column combined with tandem mass spectrometry (GC-MS/MS). Read More

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http://dx.doi.org/10.1002/rcm.8390DOI Listing
January 2019
1 Read

Can lipid removal affect interpretation of resource partitioning from stable isotopes in Southern Ocean pteropods?

Rapid Commun Mass Spectrom 2019 Jan 12. Epub 2019 Jan 12.

Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 129, Hobart, Tasmania, 7001, Australia.

Rationale: Stable isotopes analysis (SIA) is a powerful tool to estimate dietary links between polar zooplankton. However, the presence of highly variable C-rich lipids may skew estimations as they are depleted in C relative to proteins and carbohydrates, consequently masking carbon signals from food sources. Lipid effects on pteropod-specific values requires examining, since accounting for lipids is rarely conducted among the few existing pteropod-related SIA studies. Read More

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http://dx.doi.org/10.1002/rcm.8384DOI Listing
January 2019
2 Reads

A new unspiked K-Ar dating approach using laser fusion on microsamples.

Rapid Commun Mass Spectrom 2019 Jan 10. Epub 2019 Jan 10.

State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, 19 Bei-tu-cheng-xi Rd, Chaoyang District, Beijing, 100029, China.

Rationale: Issues induced by neutron irradiation makes Ar/ Ar dating inapplicable in some cases. The first issue is Ar and Ar recoil effects during irradiation that affect fine-grained minerals (<50μm), such as lunar rocks, glassy groundmass, supergene minerals (e.g. Read More

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http://dx.doi.org/10.1002/rcm.8385DOI Listing
January 2019
1 Read

Toward Understanding of the Ionization Mechanism of Matrix-Assisted Ionization using Mass Spectrometry Experiment and Theory.

Rapid Commun Mass Spectrom 2019 Jan 8. Epub 2019 Jan 8.

Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei, Taiwan.

Rationale: Matrix-assisted ionization (MAI) mass spectrometry does not require voltages, a laser beam, or added heat to initiate ionization, but it is strongly dependent on the choice of matrix and the vacuum conditions. High-charge state distributions of nonvolatile analyte ions produced by MAI suggest that the ionization mechanism may be similar to that of electrospray ionization (ESI), but different from matrix-assisted laser desorption/ionization (MALDI). While significant information is available for MAI using mass spectrometers operating at atmospheric and intermediate pressure, little is known about the mechanism at high vacuum. Read More

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http://dx.doi.org/10.1002/rcm.8382DOI Listing
January 2019
1 Read

Evaluating the Performance of Sample Preparation Methods for UPLC-MS-Based Serum Metabonomics.

Rapid Commun Mass Spectrom 2019 Jan 4. Epub 2019 Jan 4.

Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.

Rationale: Metabonomics investigating perturbation to endogenous metabolism in response to external stimuli is emerging as a powerful tool for clinical diagnosis as well as in many other areas. The ability to retrieve reliable and reproducible information from complex biological fluids such as serum is crucial for its further applications.

Methods: In this study, the performance of the commonly used sample preparation methods for UPLC-MS-based metabonomics was investigated. Read More

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http://dx.doi.org/10.1002/rcm.8381DOI Listing
January 2019
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A validated LC/MS/MS method for 4,4'-methylenedianiline quantitation in human urine as a measure of 4,4'-methylene diphenyl diisocyanate exposure.

Rapid Commun Mass Spectrom 2019 Jan 2. Epub 2019 Jan 2.

Institut de recherche Robert-Sauvé en santé et en sécurité du travail, 505 boul. De Maisonneuve Ouest, Montréal, Québec, H3A 3C2, Canada.

Rationale: 4,4'-methylene diphenyl diisocyanate (MDI) is a highly reactive isocyanate used in the production of polyurethanes. Workers exposed to these products may develop sensitization to the diisocyanate compounds, leading to occupational asthma. Quantifying MDI levels is necessary to ensure workplace safety. Read More

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http://dx.doi.org/10.1002/rcm.8380DOI Listing
January 2019
7 Reads

Laser ablation synthesis of carbon-phosphides from graphene/nanodiamond-phosphorus composite precursors: Laser desorption ionisation Time-of-Flight Mass Spectrometry.

Rapid Commun Mass Spectrom 2019 Jan 2. Epub 2019 Jan 2.

Department of Chemistry, Faculty of Science, Masaryk University, A14/326-Kamenice 753/5, 625 00, Brno, Czech Republic.

Rationale: Carbon-phosphides, are new and promising strategic materials with applications e.g. in optoelectronics. Read More

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http://dx.doi.org/10.1002/rcm.8379DOI Listing
January 2019
2 Reads

Strontium isotope ratios of human hair from the United States: Patterns and aberrations.

Rapid Commun Mass Spectrom 2018 Dec 29. Epub 2018 Dec 29.

Department of Biology, University of Utah, 257 S 1400 E, Salt Lake City, UT, 84112, USA.

Rationale: Strontium isotope ratios ( Sr/ Sr) of hair may be a valuable tool to estimate human provenance. However, the systematics and mechanisms controlling spatial variation in Sr/ Sr of modern human hair remain unclear. Here, we measure Sr/ Sr of hair specimens from across the USA to assess the presence of geospatial relationships. Read More

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http://dx.doi.org/10.1002/rcm.8378DOI Listing
December 2018
1 Read

Isotope ratio mass spectrometry in antidoping analysis: The use of endogenous reference compounds.

Rapid Commun Mass Spectrom 2018 Dec 27. Epub 2018 Dec 27.

Laboratorio Antidoping, Federazione Medico Sportiva Italiana, Largo Giulio Onesti 1, 00197, Rome, Italy.

Rationale: Isotope ratio mass spectrometry (IRMS) is a analytical technique required by the World Antidoping Agency (WADA) before releasing of an adverse finding for the abuse of pseudoendogenous steroids (i.e testosterone). For every single individual, the delta C values (‰) of the selected target compounds (TCs, i. Read More

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http://doi.wiley.com/10.1002/rcm.8377
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http://dx.doi.org/10.1002/rcm.8377DOI Listing
December 2018
3 Reads

High-Precision Magnesium Isotope Analysis of Geological and Environmental Reference Materials by Multiple-collector Inductively Coupled Plasma Mass Spectrometry.

Rapid Commun Mass Spectrom 2018 Dec 21. Epub 2018 Dec 21.

State Key Laboratory of Geological Process and Mineral Resources, School of Earth Science and Resources, China University of Geosciences, Beijing, 100083, China.

Rationale: High-precision Mg isotope analysis for geological and environmental reference materials is a prerequisite to ensure data quality before using Mg isotopes to trace geochemical and environmental processes. However, the Mg isotopic ratios of many commonly used reference materials, especially sediments, have rarely been reported. Furthermore, published values for some commonly used reference materials exhibit a significant inconsistency across laboratories and thus need more data comparison. Read More

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http://dx.doi.org/10.1002/rcm.8376DOI Listing
December 2018
1 Read

Improved isotopic model based on N tracing and Rayleigh-type isotope fractionation for simulating differential sources of N O emissions in a clay grassland soil.

Rapid Commun Mass Spectrom 2018 Dec 18. Epub 2018 Dec 18.

Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, UK.

Rationale: Isotopic signatures of N O can help distinguish between two sources (fertiliser N, or endogenous soil N) of N O emissions. The contribution of each source to N O emissions after N-application is difficult to determine. Here, isotopologue signatures of emitted N O are used in an improved isotopic model based on Rayleigh type equations. Read More

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http://dx.doi.org/10.1002/rcm.8374DOI Listing
December 2018
1 Read

Sulfur isotope analysis of microcrystalline iron sulfides using SIMS imaging: Extracting local paleo-environmental information from modern and ancient sediments.

Rapid Commun Mass Spectrom 2018 Dec 18. Epub 2018 Dec 18.

Department of Earth & Planetary Sciences, Washington University in Saint Louis, St. Louis, MO, 63130, USA.

Rationale: Sulfur isotope ratio measurements of bulk sulfide from marine sediments have often been used to reconstruct environmental conditions associated with their formation. In-situ microscale spot analyses by secondary ion mass spectrometry (SIMS) and laser ablation multiple-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) have been utilized for the same purpose. However, these techniques are not often suitable for studying small (≤10 μm) grains or for detecting intra-grain variability. Read More

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http://dx.doi.org/10.1002/rcm.8375DOI Listing
December 2018
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Investigation of the chemical structure and formation mechanism of polydopamine from self-assembly of dopamine by liquid chromatography and mass spectrometry coupled with isotope-labelling techniques.

Authors:
Wan Chan

Rapid Commun Mass Spectrom 2018 Dec 17. Epub 2018 Dec 17.

Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.

RATIONALE Dopamine (Dp) is one of the neurotransmitters released by the brain, and it was recently observed to undergo "self-polymerization" to form polydopamine (polyDp) functional materials, with poorly-understood the polymerization mechanism. In this study, we investigated the chemical structure of polyDp as well as the mechanism of its formation using a combination of mass spectrometric techniques for both liquid and solid state samples. METHODS Using the classical combustion analyses in combination with liquid chromatography coupled with spectrophotometric and mass spectrometric (MS) techniques and a 'bottom up' approach, we identified the major monomer units and a spectrum of oligomeric aggregates in the reaction mixtures of self-assembling Dp. Read More

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http://dx.doi.org/10.1002/rcm.8373DOI Listing
December 2018
1 Read

Investigations into the Performance of Travelling Wave-Enabled Conventional and Cyclic Ion Mobility Systems to Characterise Protomers of Fluoroquinolone Antibiotic Residues.

Rapid Commun Mass Spectrom 2018 Dec 14. Epub 2018 Dec 14.

Waters Corporation, Stamford Avenue, Altrincham Road, Wilmslow, SK9 4AX, UK.

Fluoroquinolones (FLQs) are a class of antimicrobial agents which have been administered to livestock for infection prevention/control and growth promotion. In this work blank porcine muscle extract (fortified with FLQs) has been screened for the FLQ protomer species (resulting from different sites of protonation) using the cumulative specificity of Ultra High Performance Liquid Chromatography coupled with Ion Mobility - Mass Spectrometry (UHPLC-IM-MS) and collision induced dissociation (CID). Collision cross sections (CCSs) and product ion spectra have been generated for the protomeric species with ΔCCS values between protomers ranging between 10-15 Å . Read More

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http://dx.doi.org/10.1002/rcm.8371DOI Listing
December 2018
1 Read

Gold-Nanoparticle-Coated Magnetic Beads for Concentration and Ionization of Analytes for Laser Desorption/Ionization Mass Spectrometry.

Rapid Commun Mass Spectrom 2018 Dec 13. Epub 2018 Dec 13.

Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749, Korea.

Rationale: Magnetic particles coated with Au NPs (Au-MAGs) were developed and used (1) for sample concentration and (2) as a solid matrix for laser adsorption/desorption (LDI)-mass spectrometry.

Methods: The Au-MAGs were prepared by (1) coating polystyrene on iron oxide NPs (PS-MNPs), (2) coating poly-l-lysine on the PS-MNPs (PLL-coated PS-MNPs), and (3) coating negatively charged Au NPs on the PLL-coated PS-MNPs (Au-MAGs).

Results: The Au-MAGs were used to concentrate the target analyte by means of electrostatic interactions between the positively charged GHP9 and the negatively charged Au-MAGs as well as selective interactions (such as gold-sulfur interactions) between glutathione (GSH) and Au-MAGs. Read More

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http://dx.doi.org/10.1002/rcm.8372DOI Listing
December 2018
1 Read

Mass Defect Filtering for Suspect Screening of Halogenated Environmental Chemicals: A Case Study of Chlorinated Organophosphate Flame Retardants.

Rapid Commun Mass Spectrom 2018 Dec 11. Epub 2018 Dec 11.

Exposure Biology, Senator Frank R. Lautenberg Environmental Health Sciences Laboratory, Department of Environmental Medicine and Public Health, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.

Rationale: Organophosphate flame retardants (OPFRs) are a class of flame retardants widely found in environmental and biological matrices that have been extensively studied due to their adverse health effects in humans. OPFRs are loosely bound chemicals that can detach from treated products and be released into indoor and outdoor environments, where they have the potential to further undergo transformation and degradation processes, in particular the chlorinated OPFRs (Cl-PFRs). Their detection remains a moving target for analysts, and traditional targeted mass spectrometry methods are suitable only for those compounds with authentic standards. Read More

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http://dx.doi.org/10.1002/rcm.8370DOI Listing
December 2018
3 Reads

Single stranded DNA structural diversity: TAGGGT from monomers to dimers to tetramer formation.

Rapid Commun Mass Spectrom 2018 Dec 3. Epub 2018 Dec 3.

Department of Chemistry & Biochemistry, Florida International University, Miami, FL.

Rationale: DNA quadruplex structures have emerged as novel drug targets, owing to their role in preventing abnormal gene transcription and maintaining telomere stability. Trapped Ion Mobility Spectrometry - Mass Spectrometry (TIMS - MS), combined with theoretical modeling, is a powerful tool for studying the kinetic intermediates of DNA complexes formed in solution and interrogated in the gas-phase after desolvation.

Methods: A TAGGGT ssDNA sequence was purchased and studied in 10 mM ammonium acetate using nESI-TIMS-MS in positive and negative ion mode. Read More

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http://dx.doi.org/10.1002/rcm.8367DOI Listing
December 2018
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TOP-DOWN LIGNOMIC MALDI-TOF-TANDEM MASS SPECTROMETRY ANALYSIS OF LIGNIN OLIGOMERS EXTRACTED FROM DATE PALM WOOD.

Rapid Commun Mass Spectrom 2018 Dec 3. Epub 2018 Dec 3.

Department of Biochemistry, Memorial University of Newfoundland, St John's, Newfoundland, A1C 5X1, Canada.

Rationale: We report for the first time the top-down lignomic analysis of the virgin released lignin (VRL) oligomers obtained from the Saudi date palm wood (SDPW), using a MALDI-TOF/TOF instrument. In addition, we are proposing new CID-MS/MS fragmentation routes for this series of unreported VRL oligomers.

Methods: We have used MALDI-TOF-MS direct analysis of the lignin oligomers mixture without any chromatographic pre-separation. Read More

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http://doi.wiley.com/10.1002/rcm.8368
Publisher Site
http://dx.doi.org/10.1002/rcm.8368DOI Listing
December 2018
8 Reads

Derivatization-Free Method for Compound-Specific Isotope Analysis of Nonexchangeable Hydrogen of 4-Bromophenol.

Rapid Commun Mass Spectrom 2018 Dec 4. Epub 2018 Dec 4.

Geological Survey of Israel, 30 Malkhei Israel St, Jerusalem, 95501, Israel.

Rationale: Compound-specific isotope analysis (CSIA) is a valuable tool in environmental chemistry and in other fields of science. Currently, hydrogen CSIA of polar compounds containing exchangeable hydrogen is uncommon. To extend the scope of CSIA applications, we present an alternative method of analysis, bypassing the typical step of derivatization. Read More

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http://dx.doi.org/10.1002/rcm.8361DOI Listing
December 2018
1 Read

Determination of the isotopic composition of single sub-micrometer-sized uranium particles by laser ablation coupled with multi-collector ICPMS.

Rapid Commun Mass Spectrom 2018 Nov 29. Epub 2018 Nov 29.

ICSM, CEA, CNRS, ENSCM, Univ Montpellier, Bat 426, Site de Marcoule, BP 17171, 30207, Bagnols-sur-Cèze, France.

Rationale: A multi-collector inductively coupled plasma (MC-ICP) mass spectrometer coupled to a UV ns-laser ablation (LA) system was used to measure uranium isotopic ratios ( U/ U, U/ U and U/ U) in single uranium particles of various sizes and isotopic compositions, including home-made sub-micrometric natural uranium particles of narrow size distribution (415 ± 60 nm).

Methods: The LA-ICP mass spectrometer was operated in wet plasma conditions thanks to simultaneous injection of the laser aerosol and water vapor through a desolvating nebulizer. The isotopic ratios were corrected for mass bias and gain factors between detectors. Read More

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http://dx.doi.org/10.1002/rcm.8366DOI Listing
November 2018
1 Read

Carbon and oxygen isotopic analyses of calcite in calcite-dolomite mixtures: optimization of selective acid extraction.

Rapid Commun Mass Spectrom 2018 Nov 28. Epub 2018 Nov 28.

State Key Laboratory of Isotope Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.

Rationale: Carbon and oxygen isotopic compositions of individual minerals in calcite-dolomite mixtures could be measured using selective acid extraction technique based on the different reaction rates of calcite and dolomite with phosphoric acid. However, poor accuracies of calcite are usually obtained when mixtures of low calcite content are analyzed, which may result in incorrect conclusions. To overcome this shortcoming, improvements are needed in accuracy and precision when using the technique with mixtures of low calcite content. Read More

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http://dx.doi.org/10.1002/rcm.8365DOI Listing
November 2018
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Improvement of the N gas flux method for in situ measurement of soil denitrification and its product stoichiometry.

Rapid Commun Mass Spectrom 2018 Nov 25. Epub 2018 Nov 25.

Thünen Institute of Climate-Smart Agriculture, Bundesallee 65, 38116, Braunschweig, Germany.

Rationale: Field measurement of denitrification in agricultural ecosystems using the N gas flux method has been limited by poor sensitivity because current isotope ratio mass spectrometry is not precise enough to detect low N fluxes in the presence of a high atmospheric N background. For laboratory studies, detection limits are improved by incubating soils in closed systems and under N -depleted atmospheres.

Methods: We developed a new procedure to conduct the N gas flux method suitable for field application using an artificially N -depleted atmosphere to improve the detection limit at the given precision of mass spectrometry. Read More

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http://dx.doi.org/10.1002/rcm.8363DOI Listing
November 2018
1 Read

Meet the Associate Editors: Stephen Holman.

Authors:
Stephen Holman

Rapid Commun Mass Spectrom 2018 Nov 24. Epub 2018 Nov 24.

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http://dx.doi.org/10.1002/rcm.8364DOI Listing
November 2018
1 Read

Discriminating normal regions within cancerous hen ovarian tissue using multivariate hyperspectral image analysis.

Rapid Commun Mass Spectrom 2019 Feb;33(4):381-391

Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, 45137-66731, Iran.

Rationale: Identification of subregions under different pathological conditions on cancerous tissue is of great significance for understanding cancer progression and metastasis. Infrared matrix-assisted laser desorption electrospray ionization mass spectrometry (IR-MALDESI-MS) can be potentially used for diagnostic purposes since it can monitor spatial distribution and abundance of metabolites and lipids in biological tissues. However, the large size and high dimensionality of hyperspectral data make analysis and interpretation challenging. Read More

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http://dx.doi.org/10.1002/rcm.8362DOI Listing
February 2019
9 Reads

Methyl sulfates as methoxy isotopic reference materials for δ C and δ H measurements.

Rapid Commun Mass Spectrom 2019 Feb;33(4):343-350

Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, 69120, Heidelberg, Germany.

Rationale: Stable hydrogen and carbon isotope ratios of methoxy groups (OCH ) of plant organic matter have many potential applications in biogeochemical, atmospheric and food research. So far, most of the analyses of plant methoxy groups by isotope ratio mass spectrometry have employed liquid iodomethane (CH I) as the reference material to normalise stable isotope measurements of these moieties to isotope-δ scales. However, comparisons of measurements of stable hydrogen and carbon isotopes of plant methoxy groups are still hindered by the lack of suitable reference materials. Read More

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http://doi.wiley.com/10.1002/rcm.8355
Publisher Site
http://dx.doi.org/10.1002/rcm.8355DOI Listing
February 2019
10 Reads