Read by QxMD icon Read

Rapid Communications in Mass Spectrometry: RCM

Yue Ruan, Les Bluck, James Smith, Adrian Mander, Priya Singh, Michelle Venables
RATIONALE: The doubly labelled water (DLW) method is the reference method for the estimation of free-living total energy expenditure (TEE). In this method, where both (2) H and (18) O are employed, different approaches have been adopted to deal with the non-conformity observed regarding the distribution space for the labels being non-coincident with total body water. However, the method adopted can have a significant effect on the estimated TEE. METHODS: We proposed a Bayesian reasoning approach to modify an assumed prior distribution for the space ratio using experimental data to derive the TEE...
October 13, 2017: Rapid Communications in Mass Spectrometry: RCM
Kun Yang, Ya-Jun Huang, Sa Xiao, Yan-Chun Liu, Zhi-Liang Sun, Yi-Song Liu, Qi Tang, Zhao-Ying Liu
RATIONALE: Gelsemine has been extensively studied because of its anti-tumor, immunomodulatory, insecticidal itching and other significant effect. However, limited information on the pharmacokinetics and metabolism of gelsemine has been reported. Therefore, the purpose of the present study was to investigate the in vitro metabolism of gelsemine in rat liver S9 by using a rapid and accurate high-performance liquid chromatography/ quadrupole-time-of-flight mass spectrometry (HPLC/QqTOF-MS)...
October 13, 2017: Rapid Communications in Mass Spectrometry: RCM
Le Zhang, Zhong-Yuan Ren, Ya-Dong Wu, Nan Li
RATIONALE: In-situ Sr isotope analysis of geological samples by laser ablation multiple collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) provides useful information about magma mixing, crustal contamination and crystal residence time. Without chemical separation, during Sr isotope analysis with laser ablation, many kinds of interference ions (such as Rb(+) and Kr(+) ) are on the Sr isotope spectrum. Most previous in-situ Sr isotope studies only focused on Sr-enriched minerals (e...
October 13, 2017: Rapid Communications in Mass Spectrometry: RCM
Fidele Tugizimana, Paul A Steenkamp, Lizelle A Piater, Ian A Dubery
RATIONALE: Liquid chromatography coupled to mass spectrometry (LC-MS) is a dominant analytical platform in metabolomics, because of high sensitivity and resolution, thus enabling large-scale coverage of metabolomes. Correspondingly, electrospray ionisation (ESI) is the favoured ionisation method in untargeted LC-MS metabolomics given the ability to produce large numbers of ions. In the workflow of LC-ESI-MS metabolomics, maximising the ionisation efficiency over a wide mass range is inevitably an essential and determining step, subsequently defining the extent of coverage of the metabolome under investigation...
October 9, 2017: Rapid Communications in Mass Spectrometry: RCM
Nicholas S Lloyd, Aleksey Yu Sadekov, Sambuddha Misra
RATIONALE: Boron isotope ratios (δ(11) B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts. METHODS: 10(13) ohm amplifier technology has previously been applied to several radiogenic systems, but has thus far not been applied to non-traditional stable isotopes...
October 9, 2017: Rapid Communications in Mass Spectrometry: RCM
Gordon W Irvine, Lina Heinlein, Justin B Renaud, Mark W Sumarah, Martin J Stillman
RATIONALE: Metallothioneins (MTs) are a class of dynamic proteins that have been investigated extensively using mass spectrometric methods due to their amenability to ionization. Here we detect the formation of oxidative and non-oxidative MT dimers using high resolution mass spectrometry which has previously been overlooked with lower resolution techniques. METHODS: Recombinant human MT1a and its isolated domain fragments were analyzed by high-resolution Thermo Q-Exactive and Bruker-TOF MS...
October 7, 2017: Rapid Communications in Mass Spectrometry: RCM
Hardy Z Castada, Victoria Polentz, Sheryl Barringer, Macdonald Wick
RATIONALE: 4-Alkyl-branched chain fatty acids and 3-methylindole are characteristic flavor compounds associated with sheep meat. Determining their partitioning behavior between the gas and condensed phase and ultimately developing a correlation between the compound's headspace concentration and sensory descriptive grouping are important for high throughput characterization and grading classification. METHODS: The headspace concentrations of 3-methylindole, 4-methyloctanoic acid, 4-ethyloctanoic acid, and 4-methylnonanoic acid above corn oil-based standard solutions, and lamb fat samples were measured using selected ion flow tube-mass spectrometry (SIFT-MS)...
October 7, 2017: Rapid Communications in Mass Spectrometry: RCM
Xiang-Ping Zha, Bing Gong, Yong-Fei Zheng, Yi-Xiang Chen
RATIONALE: Continuous-flow isotope ratio mass spectrometry (CF-IRMS) is a specialized technique used to quickly analyze very small amounts of sample. We have used CF-IRMS to assess the influences of sample weight and relative carbon content on the accuracy and precision of the δ(13) C values of micro amounts of carbonate and non-carbonate in silicate rocks. METHODS: The analytical work was performed on a Gasbench II (GB) sample preparation device and on an Element Analyzer (EA), which were both interfaced to CF-IRMS instruments...
October 7, 2017: Rapid Communications in Mass Spectrometry: RCM
J Blees, M Saurer, R T W Siegwolf, V Ulevicius, A S H Prevôt, J Dommen, M M Lehmann
RATIONALE: Levoglucosan is formed from cellulose during biomass burning. It is therefore often used as a specific tracer to quantify the contribution of wood burning to the aerosol loading. The stable oxygen isotope composition (δ(18) O value) of biomass is determined by the water cycle and varies regionally, and hence the δ(18) O value of levoglucosan could help to identify source regions of organic aerosols. METHODS: After solvent extraction of the organic fraction and concentration steps, a recently developed methylation derivatisation technique was applied on experimental (i...
October 3, 2017: Rapid Communications in Mass Spectrometry: RCM
Lingzhi Gong
RATIONALE: Hydrophilic interaction liquid chromatography/electrospray ionization mass spectrometry (HILIC-LC/ESI-MS) has been proved to be useful for quality control of oligonucleotides. However, the lack of separation for some oligonucleotides using HILIC-LC-MS has proved problematic. This study aimed to improve the resolving ability of HILIC-LC-MS. METHODS: The study was performed on a Waters UPLC® system coupled to a Waters LCT premier XE ESI-TOF mass spectrometer using a Zorbax® RRHD HILIC column (2...
October 3, 2017: Rapid Communications in Mass Spectrometry: RCM
Ruwimbo Mutirwara, Frans G T Radloff, Daryl Codron
RATIONALE: Stable isotope analysis (SIA) of whiskers has been used to identify temporal feeding habits, intra-population diet variation, as well as individual dietary specialisation of marine and terrestrial carnivores. However, the potential of the method to disclose such dietary information for large wild felids is hampered by lack of information on species-specific whisker growth rates, whisker growth patterns and whisker-diet trophic discrimination factors (TDFs). METHODS: Whisker growth rates and growth patterns were measured for four lions Panthera leo and one leopard Panthera pardus held at the National Zoological Gardens, Pretoria, South Africa...
October 3, 2017: Rapid Communications in Mass Spectrometry: RCM
Kevin A Kovalchik, Matthew S MacLennan, Kerry M Peru, Chukwuemeka Ajaero, Dena W McMartin, John V Headley, David D Y Chen
RATIONALE: The characterization of naphthenic acid fraction compounds (NAFCs) in oil sands process affected water (OSPW) is of interest for both toxicology studies and regulatory reasons. Previous studies utilizing authentic standards have identified dicarboxylic naphthenic acids using two-dimensional gas chromatography hyphenated to time-of-flight mass spectrometry (GCxGC/TOFMS). The selective derivatization of hydroxyl groups has also recently aided in the characterization of oxy-NAFCs, and indirectly the characterization of dicarboxylic NAFCs...
September 25, 2017: Rapid Communications in Mass Spectrometry: RCM
Rossella Guerrieri, Katie Jennings, Soumaya Belmecheri, Heidi Asbjornsen, Scott Ollinger
RATIONALE: We evaluated the applicability of tree ring δ(13) C and δ(18) O values in bulk wood - instead of the more time and lab-consuming α-cellulose δ(13) C and δ(18) O values, for assessing climate and physiological signals across multiple sites and for six tree species along a latitudinal gradient (35°97(') N to 45°20(') N) of the northeastern United States. METHODS: Wood cores (n=4 per tree) were sampled from ten trees per species. Cores were cross-dated within and across trees at each site, and for the last 30 years...
September 22, 2017: Rapid Communications in Mass Spectrometry: RCM
Reinhard Langel, Jens Dyckmans
RATIONALE: One important limitation for the precise measurement of minute amounts of N in solid samples by elemental analyser/isotope ratio mass spectrometry (EA/IRMS) is the accurate determination of the analyser blank value. This study was performed to identify different sources, amounts and isotopic composition of N blanks in EA/IRMS in order to identify measures for minimizing the effect of the N blank on N isotopic data quality. METHODS: Different types of autosamplers, with and without zero-blank functionality, were tested by analysing different amounts of substances of varying isotopic composition by EA/IRMS...
September 21, 2017: Rapid Communications in Mass Spectrometry: RCM
John A Mohan, Thomas C TinHan, Nathan R Miller, R J David Wells
RATIONALE: Application of vertebral chemistry in elasmobranchs has the potential to progress our understanding of individual migration patterns and population dynamics. However, the influence of handling artifacts such as sample cleaning and storage on vertebral chemistry is unclear and requires experimental investigation. METHODS: Vertebrae centra from blacktip sharks (Carcharhinus limbatus) were cleaned with bleach (NaOCl) for five minutes (m), 1 hour (h) and 24 (h) in a cleaning experiment and stored frozen, in 70% ethanol, and 10% formalin treatments for 20 days in a storage experiment...
September 20, 2017: Rapid Communications in Mass Spectrometry: RCM
S M Shugurov, O Yu Kurapova, S I Lopatin, V G Konakov, E A Vasil'eva
RATIONALE: Zirconia doped with a lanthanum oxide system is of high interest due to its exceptional thermal stability for the development of high performance ceramics. It possesses the beneficial properties of pure zirconia, such as heat resistance, mechanical strength and inertness, but also eliminates its main disadvantage, i.e. brittleness. At high temperatures, components of such systems may vaporize selectively, leading to significant change in composition, and hence, the thermal resistance, phase stability and performance of the ceramic materials...
September 20, 2017: Rapid Communications in Mass Spectrometry: RCM
François Fourel, Christophe Lécuyer, Attila Demeny, Philippe Boulvais, Lutz Lange, Dorrit E Jacob, Istvan Kovacs
RATIONALE: We have used ahigh-precision, high efficiency method for themeasurementof the(2) H/(1) H ratios of hydrous silicates (amphiboles) and nominally anhydrous minerals (NAM) such as clinopyroxene, garnet and diamond, which are usually extremely resistant to pyrolysis. This opens up new fields of investigation to better understand the conditionsof formation fordeep-Earth minerals. METHOD: The technique described hereinvolvesIsotopic Ratio Mass Spectrometry (IRMS) online in continuous flow mode with an Elemental Analyzer (EA) using"purge and trap" technology rather than conventional packed column-GC gas separation...
September 20, 2017: Rapid Communications in Mass Spectrometry: RCM
Qing-Shan Zhang, Gao-Wa Wang, Zhi-Qiang Han, Xiang-Mei Chen, Risu Na, Haburi Jin, Ping Li, Renbatu Bu
RATIONALE: Rhizoma coptidis extract and its alkaloids show various pharmacological activities, but its metabolic profile in human plasma has not been thoroughly investigated. In the present research, the metabolism of Rhizoma coptidis at a clinical dose (5 g/60 kg/day) was systematically analyzed to determine its biotransformation processes in human plasma. METHODS: In this research, the metabolites of Rhizoma coptidis in human plasma after oral administration of Rhizoma coptidis extract at a clinical dose were investigated using ultra high-performance liquid chromatography (UHPLC) coupled with high-resolution LTQ-Orbitrap mass spectrometry...
September 19, 2017: Rapid Communications in Mass Spectrometry: RCM
Debora Fabbri, Paola Calza, Giorgio Noè, Valentina Santoro, Claudio Medana
RATIONALE: Ionic liquids (ILs) are a subject of active research in the field of alternative solvents. We studied the behaviour of a piperidine IL, 1-butyl-1-methylpiperidinium tetrafluoroborate (BMPA), through the elucidation of its transformation products (TPs) in water. METHODS: The transformation pathways of BMPA were investigated using high-performance liquid chromatography (HPLC) combined with a hybrid LTQ-Orbitrap instrument on the basis of mass defect filtering...
September 14, 2017: Rapid Communications in Mass Spectrometry: RCM
Meng Miao, Gaosheng Zhao, Yaliang Wang, Li Xu, Junguo Dong, Ping Cheng
RATIONALE: Drug abuse or dependence results in a series of social problems, including crime and traffic accidents. Spray inlet microwave plasma torch tandem mass spectrometry (MPT-MS/MS) was developed and used for the direct detection of such drugs in liquid solutions. METHODS: Drug sample solutions were directly sprayed into the flame of MPT by a sampling pump and the ions produced by Penning ionization and ion-molecule reactions were guided into a QTOF tandem mass spectrometer for mass analysis...
September 14, 2017: Rapid Communications in Mass Spectrometry: RCM
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"