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https://www.readbyqxmd.com/read/29145172/volatiles-from-cinnamomum-cassia-buds
#1
Daniel Sandner, Ulrich Krings, Ralf G Berger
While the chemical composition of leaf and stem bark essential oils of the Chinese cinnamon, Cinnamomum cassia (L.) J. Presl, has been well investigated, little is known about the volatilom of its buds, which appeared recently on German markets. Soxhlet extracts of the commercial samples were prepared, fractionated using silica gel and characterised by gas chromatography-flame ionisation detector (GC-FID) for semi-quantification, by gas chromatography-mass spectrometry (GC-MS) for identification and by GC-FID/olfactometry for sensory evaluation...
November 16, 2017: Zeitschrift Für Naturforschung. C, A Journal of Biosciences
https://www.readbyqxmd.com/read/29143214/cellular-processing-of-gold-nanoparticles-ce-icp-ms-evidence-for-the-speciation-changes-in-human-cytosol
#2
Joanna Legat, Magdalena Matczuk, Andrei R Timerbaev, Maciej Jarosz
The cellular uptake of gold nanoparticles (AuNPs) may (or may not) affect their speciation, but information on the chemical forms in which the particles exist in the cell remains obscure. An analytical method based on the use of capillary electrophoresis hyphenated with inductively coupled plasma mass spectrometry (ICP-MS) has been proposed to shed light on the intracellular processing of AuNPs. It was observed that when being introduced into normal cytosol, the conjugates of 10-50 nm AuNPs with albumin evolved in human serum stayed intact...
November 15, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29141052/association-between-urinary-manganese-and-blood-pressure-results-from-national-health-and-nutrition-examination-survey-nhanes-2011-2014
#3
Cynthia Wu, Jessica G Woo, Nanhua Zhang
Manganese is a trace mineral required for metabolism, growth and tissue formation, and reproduction. It is mainly obtained through food and water, as well as through occupational exposure. This study used data from National Health and Nutrition Examination Survey, combining the 2011-12 and 2013-14 cycles. We conducted linear regression analyses on urinary manganese and blood pressure. Significant negative associations (p<0.01) between urinary manganese and both systolic and diastolic blood pressure existed after adjusting for age, sex, body mass index, race/ethnicity, and status of taking antihypertensive medication...
2017: PloS One
https://www.readbyqxmd.com/read/29137126/carbon-nanotubes-effect-on-mitochondrial-oxygen-flux-dynamics-polarography-experimental-study-and-machine-learning-models-using-star-graph-trace-invariants-of-raman-spectra
#4
Michael González-Durruthy, Jose M Monserrat, Bakhtiyor Rasulev, Gerardo M Casañola-Martín, José María Barreiro Sorrivas, Sergio Paraíso-Medina, Víctor Maojo, Humberto González-Díaz, Alejandro Pazos, Cristian R Munteanu
This study presents the impact of carbon nanotubes (CNTs) on mitochondrial oxygen mass flux (Jm) under three experimental conditions. New experimental results and a new methodology are reported for the first time and they are based on CNT Raman spectra star graph transform (spectral moments) and perturbation theory. The experimental measures of Jm showed that no tested CNT family can inhibit the oxygen consumption profiles of mitochondria. The best model for the prediction of Jm for other CNTs was provided by random forest using eight features, obtaining test R-squared (R²) of 0...
November 11, 2017: Nanomaterials
https://www.readbyqxmd.com/read/29136903/multivariate-optimization-of-a-procedure-employing-microwave-assisted-digestion-for-the-determination-of-nickel-and-vanadium-in-crude-oil-by-icp-oes
#5
Shirlei L Dos Anjos, Jeferson C Alves, Sarah A Rocha Soares, Rennan G O Araujo, Olivia M C de Oliveira, Antonio F S Queiroz, Sergio L C Ferreira
This work presents the optimization of a sample preparation procedure using microwave-assisted digestion for the determination of nickel and vanadium in crude oil employing inductively coupled plasma optical emission spectrometry (ICP OES). The optimization step was performed utilizing a two-level full factorial design involving the following factors: concentrated nitric acid and hydrogen peroxide volumes, and microwave-assisted digestion temperature. Nickel and vanadium concentrations were used as responses...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136838/a-robotic-magnetic-nanoparticle-solid-phase-extraction-system-coupled-to-flow-batch-analyzer-and-gfaas-for-determination-of-trace-cadmium-in-edible-oils-without-external-pretreatment
#6
Inakã S Barreto, Stefani I E Andrade, Francisco A S Cunha, Marcelo B Lima, Mario Cesar U Araujo, Luciano F Almeida
A lab-made magnetic-mechanical robotic (MMR) system coupled to a flow-batch analyzer (FBA) for magnetic nanoparticles solid phase extraction (MSPE) is presented. As an illustrative application, an NMR-FBA couple was connected to a graphite furnace atomic absorption spectrometer (GFAAS) for quantification of trace cadmium in edible oils. Factors affecting MSPE, such as the amount of adsorbent, the type, concentration and volume of the eluent and elution time were studied. Under the optimized experimental conditions, the interferents studied did not reveal a significant change in the analytical response, indicating that proposed method is selective...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136808/an-approach-for-quantification-of-platinum-distribution-in-tissues-by-la-icp-ms-imaging-using-isotope-dilution-analysis
#7
I Moraleja, M L Mena, A Lázaro, B Neumann, A Tejedor, N Jakubowski, M M Gómez-Gómez, D Esteban-Fernández
Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been revealed as a convenient technique for trace elemental imaging in tissue sections, providing elemental 2D distribution at a quantitative level. For quantification purposes, in the last years several approaches have been proposed in the literature such as the use of CRMs or matrix matched standards. The use of Isotope Dilution (ID) for quantification by LA-ICP-MS has been also described, being mainly useful for bulk analysis but not feasible for spatial measurements so far...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136802/carboxylated-carbon-nanospheres-as-solid-phase-extraction-adsorbents-for-the-determination-of-perfluorinated-compounds-in-water-samples-by-liquid-chromatography-tandem-mass-spectrometry
#8
Xia Wang, Ying Zhang, Fu-Wei Li, Ru-Song Zhao
This work demonstrates the extraction potential of carboxylated carbon nanospheres (CNSs-COOH) for solid-phase extraction of perfluoroalkyl acids (PFAAs) for the first time. Six PFAAs, including perfluorohexanesulfonate (PFHxS), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorooctanoic sulfonic (PFOS), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA), were quantitatively adsorbed on a CNSs-COOH-packed cartridge; then, the PFAAs retained on the adsorbent were quantitatively eluted with an optimized volume of acetone (pH = 10)...
February 1, 2018: Talanta
https://www.readbyqxmd.com/read/29136518/evidence-of-co-metabolic-bentazone-transformation-by-methanotrophic-enrichment-from-a-groundwater-fed-rapid-sand-filter
#9
Mathilde J Hedegaard, Hélène Deliniere, Carsten Prasse, Arnaud Dechesne, Barth F Smets, Hans-Jørgen Albrechtsen
The herbicide bentazone is recalcitrant in aquifers and is therefore frequently detected in wells used for drinking water production. However, bentazone degradation has been observed in filter sand from a rapid sand filter at a waterworks with methane-rich groundwater. Here, the association between methane oxidation and removal of bentazone was investigated with a methanotrophic enrichment culture derived from methane-fed column reactors inoculated with that filter sand. Several independent lines of evidence obtained from microcosm experiments with the methanotrophic enrichment culture, tap water and bentazone at concentrations below 2 mg/L showed methanotrophic co-metabolic bentazone transformation: The culture removed 53% of the bentazone in 21 days in presence of 5 mg/L of methane, while only 31% was removed in absence of methane...
November 3, 2017: Water Research
https://www.readbyqxmd.com/read/29135232/confocal-raman-microscopy-for-the-determination-of-protein-and-quaternary-ammonium-ion-loadings-in-biocatalytic-membranes-for-electrochemical-energy-conversion-and-storage
#10
Rong Cai, Sofiene Abdellaoui, Jay P Kitt, Cullen Irvine, Joel Harris, Shelley D Minteer, Carol Korzeniewski
The need to immobilize active enzyme, while ensuring high rates of substrate turnover and electronic charge transfer with an electrode, is a centrally important challenge in the field of bioelectrocatalysis. In this work, we demonstrate the use of confocal Raman microscopy as a tool for quantitation and molecular-scale structural characterization of ionomers and proteins within biocatalytic membranes to aid in the development of energy efficient biofuel cells. A set of recently available short side chain Aquivion ionomers spanning a range of equivalent weight (EW) suitable for enzyme immobilization was investigated...
November 14, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29135035/analysis-and-measurement-of-serotonin
#11
REVIEW
András Seitz, Stelvio M Bandiera
Serotonin, also known as 5-hydroxytryptamine, is an important signaling molecule in the central and peripheral nervous systems of humans. Acting through several receptor types, it helps regulate the normal functioning of the gastrointestinal tract, cardiovascular system and brain. Serotonin signaling has also been implicated in the etiology of several diseases, including depression, anxiety disorders, hypertension and irritable bowel syndrome. The present review focuses on the chemical analysis of serotonin in biological fluids and biomatrices and traces the development and application of early methods based on UV absorbance or fluorescence to more widely-used current methods such as high-performance liquid chromatography coupled to mass spectrometry...
November 14, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/29132825/preconcentration-and-partial-separation-of-nitroaromatic-vapors-using-a-methyltrimethoxysilane-based-sol-gel
#12
Michelle M Cerreta, Kevin J Johnson, Braden C Giordano
Typical trace vapor analysis involves sorbent trapping, followed by desorption and chromatographic separation. This communication describes a method for streamlining this process by combining sorbent sampling/preconcentration with partial separation achieved through temperature-programmed thermal desorption. A novel sorbent trap was formulated in which tubular glass liners for a programmable-temperature gas chromatograph inlet were coated with a sol-gel based polymer stationary phase synthesized from methyltrimethoxysilane precursor and installed into the inlet, which was directly connected to a mass-selective detector by a fused silica capillary transfer line...
November 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/29131975/identification-of-urinary-biomarkers-of-exposure-to-di-2-propylheptyl-phthalate-using-high-resolution-mass-spectrometry-and-two-data-screening-approaches
#13
Chia-Lung Shih, Pao-Mei Liao, Jen-Yi Hsu, Yi-Ning Chung, Victor G Zgoda, Pao-Chi Liao
Di-(2-propylheptyl) phthalate (DPHP) is a plasticizer used in polyvinyl chloride and vinyl chloride copolymer that has been suggested to be a toxicant in rats and may affect human health. Because the use of DPHP is increasing, the general German population is being exposed to DPHP. Toxicant metabolism is important for human toxicant exposure assessments. To date, the knowledge regarding DPHP metabolism has been limited, and only four metabolites have been identified in human urine. Ultra-performance liquid chromatography was coupled with Orbitrap high-resolution mass spectrometry (MS) and two data-screening approaches-the signal mining algorithm with isotope tracing (SMAIT) and the mass defect filter (MDF)-for DPHP metabolite candidate discovery...
October 30, 2017: Chemosphere
https://www.readbyqxmd.com/read/29129866/determination-of-trace-fission-products-associated-with-thorium-and-hcl-matrix-by-inductively-coupled-plasma-mass-spectrometry-after-anion-exchange-separation
#14
Shuhua He, Mumei Chen, Zheng Li, Haixia Cong, Lan Zhang, Qinnuan Li
For the determination of μg-mg L(-1) of FPs in 100 g L(-1) of thorium matrix with HCl medium, a method, including anion-exchange pre-separation, evaporation and inductively coupled plasma mass spectrometry (ICP-MS) measurement, was developed. The procedure parameters, such as the matrix effect of thorium, the acidity of separation, the elution curve of thorium and FPs and the temperature of evaporation were optimized by batch equilibration, column elution and evaporation experiments. It was found that the average recovery of the FPs was in the range 80 - 110%, and the RSD values were in the range 2 - 15% utilizing prior anion exchange separation of FPs from thorium samples...
2017: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
https://www.readbyqxmd.com/read/29129604/simultaneous-determination-of-nine-kinds-of-dominating-bile-acids-in-various-snake-bile-by-ultrahigh-performance-liquid-chromatography-with-triple-quadrupole-linear-iontrap-mass-spectrometry
#15
Jie Zhang, Yeqin Fan, Yajun Gong, Xiaoyong Chen, Luosheng Wan, Chenggao Zhou, Jiewen Zhou, Shuangcheng Ma, Feng Wei, Jiachun Chen, Jing Nie
Snake bile is one of the most expensive traditional Chinese medicines (TCMs). However, due to the complicated constitutes of snake bile and the poor ultraviolet absorbance of some trace bile acids (BAs), effective analysis methods for snake bile acids were still unavailable, making it difficult to solve adulteration problems. In present study, ultrahigh-performance liquid chromatography with triple quadrupole linear ion trap mass spectrometry (UHPLC-QqQ-MS/MS) was applied to conduct a quantitative analysis on snake BAs...
November 9, 2017: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
https://www.readbyqxmd.com/read/29129061/a-highly-sensitive-and-high-throughput-method-for-the-analysis-of-bisphenol-analogues-and-their-halogenated-derivatives-in-breast-milk
#16
Yumin Niu, Bin Wang, Yunfeng Zhao, Jing Zhang, Bing Shao
The structural analogs of bisphenol A (BPA) and their halogenated derivatives (together referred as BPs) have been found in environment, food and even human. Limited research showed that some of them exhibited similar to or even greater toxicities than BPA. Therefore, adverse effects on humans with low-dose in early life exposure were expected for BPs. Breast milk is an excellent matrix could reflect fetus and babies exposure to contaminants. Some of the emerging BPs may present with trace or ultra-trace levels in human...
November 13, 2017: Journal of Agricultural and Food Chemistry
https://www.readbyqxmd.com/read/29128681/physicochemical-transformation-of-fe-ni-bimetallic-nanoparticles-during-aging-in-simulated-groundwater-and-the-consequent-effect-on-contaminant-removal
#17
Haoran Dong, Zhao Jiang, Junmin Deng, Cong Zhang, Yujun Cheng, Kunjie Hou, Lihua Zhang, Lin Tang, Guangming Zeng
To assess the fate and long-term reactivity of bimetallic nanoparticles used in groundwater remediation, it is important to trace the physicochemical transformation of nanoparticles during aging in water. This study investigated the short-term (within 5 d) and long-term (up to 90 d) aging process of Fe/Ni bimetallic nanoparticles (Fe/Ni BNPs) in simulated groundwater and the consequent effect on the particle reactivity. Results indicate that the morphological, compositional and structural transformation of Fe/Ni BNPs happened during the aging...
November 4, 2017: Water Research
https://www.readbyqxmd.com/read/29126886/platinum-palladium-rhodium-molybdenum-and-strontium-in-blood-of-urban-women-in-nine-countries
#18
Gerda Rentschler, Ilia Rodushkin, Milena Cerna, Chunying Chen, Florencia Harari, Raúl Harari, Milena Horvat, Frantiska Hruba, Lucie Kasparova, Kvetoslava Koppova, Andrea Krskova, Mladen Krsnik, Jawhar Laamech, Yu-Feng Li, Lina Löfmark, Thomas Lundh, Nils-Göran Lundström, Badiaa Lyoussi, Darja Mazej, Josko Osredkar, Krystyna Pawlas, Natalia Pawlas, Adam Prokopowicz, Staffan Skerfving, Janja Snoj Tratnik, Vera Spevackova, Zdravko Spiric, Anneli Sundkvist, Ulf Strömberg, Drazenka Vadla, Katerina Wranova, Soumia Zizi, Ingvar A Bergdahl
BACKGROUND: There is little reliable information on human exposure to the metals platinum (Pt), palladium (Pd) and rhodium (Rh), despite their use in enormous quantities in catalytic converters for automobile exhaust systems. OBJECTIVES: To evaluate blood concentrations of Pt (B-Pt), Pd (B-Pd) and Rh (B-Rh) in women from six European and three non-European countries, and to identify potentially influential factors. In addition, molybdenum (Mo) and strontium (Sr) were analysed...
November 2, 2017: International Journal of Hygiene and Environmental Health
https://www.readbyqxmd.com/read/29126475/development-and-application-of-mass-spectrometric-techniques-for-ultra-trace-determination-of-236-u-in-environmental-samples-a-review
#19
REVIEW
Wenting Bu, Jian Zheng, Michael E Ketterer, Sheng Hu, Shigeo Uchida, Xiaolin Wang
Measurements of the long-lived radionuclide (236)U are an important endeavor, not only in nuclear safeguards work, but also in terms of using this emerging nuclide as a tracer in chemical oceanography, hydrology, and actinide sourcing. Depending on the properties of a sample and its neutron irradiation history, (236)U/(238)U ratios from different sources vary significantly. Therefore, this ratio can be treated as an important fingerprint for radioactive source identification, and in particular, affords a definitive means of discriminating between naturally occurring U and specific types of anthropogenic U...
December 1, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/29126108/laboratory-scale-photobiotechnology-current-trends-and-future-perspectives
#20
Holger Morschett, Varun Loomba, Gregor Huber, Wolfgang Wiechert, Eric von Lieres, Marco Oldiges
Phototrophic bioprocesses are a promising puzzle piece in future bio-economy concepts but mostly fail for economic reasons, yet. Besides other aspects, this is mainly attributed to the omnipresent issue of optimal light supply impeding scale-up and -down of phototrophic processes according to classic established concepts. This MiniReview examines two current trends in photobiotechnology, namely microscale cultivation and modeling and simulation. Micro photobioreactors are a valuable and promising trend with microfluidic chips and microtiter plates as predominant design concepts...
November 8, 2017: FEMS Microbiology Letters
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