keyword
MENU ▼
Read by QxMD icon Read
search

Analytical chemistry

keyword
https://www.readbyqxmd.com/read/28541350/ultrasensitive-and-reproducible-sers-platform-of-coupled-ag-grating-with-multibranched-au-nanoparticles
#1
Yevgeniya Kalachyova, David Mares, Vitezslav Jerabek, Pavel Ulbrich, Ladislav Lapcak, Vaclav Svorcik, Oleksiy Lyutakov
Surface-enhanced Raman scattering (SERS) spectroscopy is an extremely sensitive analytical technique that is capable of identifying the vibration signatures of target molecules up to single-molecule sensitivity. In this work, the ultrahigh sensitivity of SERS has been achieved through the immobilization of sharp-edges specific nanoparticles - so-called gold multibranched NPs (AuMs) on the silver grating surface through the biphenyl dithiol. This approach allows combining the extremely high SERS enhancement factor (better than that in the case of AuMs immobilized on the flat Ag film) with perfect reproducibility of Raman signals...
May 25, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28535883/paper-based-microfluidic-devices-on-the-crime-scene-a-simple-tool-for-rapid-estimation-of-post-mortem-interval-using-vitreous-humour
#2
Paulo T Garcia, Ellen F M Gabriel, Gustavo S Pessôa, Júlio C Santos Júnior, Pedro C Mollo Filho, Ruggero B F Guidugli, Nelci F Höehr, Marco A Z Arruda, Wendell K T Coltro
This paper describes for the first time the use of paper-based analytical devices at crime scenes to estimate the post-mortem interval (PMI), based on the colorimetric determination of Fe(2+) in vitreous humour (VH) samples. Experimental parameters such as the paper substrate, the microzone diameter, the sample volume and the 1,10-phenanthroline (o-phen) concentration were optimised in order to ensure the best analytical performance. Grade 1 CHR paper, microzone with diameter of 5 mm, a sample volume of 4 μL and an o-phen concentration of 0...
June 29, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28535882/versatile-fabrication-of-paper-based-microfluidic-devices-with-high-chemical-resistance-using-scholar-glue-and-magnetic-masks
#3
Thiago M G Cardoso, Fabrício R de Souza, Paulo T Garcia, Denilson Rabelo, Charles S Henry, Wendell K T Coltro
Simple methods have been developed for fabricating microfluidic paper-based analytical devices (μPADs) but few of these devices can be used with organic solvents and/or aqueous solutions containing surfactants. This study describes a simple fabrication strategy for μPADs that uses readily available scholar glue to create the hydrophobic flow barriers that are resistant to surfactants and organic solvents. Microfluidic structures were defined by magnetic masks designed with either neodymium magnets or magnetic sheets to define the patter, and structures were created by spraying an aqueous solution of glue on the paper surface...
June 29, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28533770/from-vineyard-soil-to-wine-fermentation-microbiome-approximations-to-explain-the-terroir-concept
#4
REVIEW
Ignacio Belda, Iratxe Zarraonaindia, Matthew Perisin, Antonio Palacios, Alberto Acedo
Wine originally emerged as a serendipitous mix of chemistry and biology, where microorganisms played a decisive role. From these ancient fermentations to the current monitored industrial processes, winegrowers and winemakers have been continuously changing their practices according to scientific knowledge and advances. A new enology direction is emerging and aiming to blend the complexity of spontaneous fermentations with industrial safety of monitored fermentations. In this context, wines with distinctive autochthonous peculiarities have a great acceptance among consumers, causing important economic returns...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28533633/photolithography-free-laser-patterned-hf-acid-resistant-chromium-polyimide-mask-for-rapid-fabrication-of-microfluidic-systems-in-glass
#5
Konstantin O Zamuruyev, Yuriy Zrodnikov, Cristina E Davis
Excellent chemical and physical properties of glass, over a range of operating conditions, make it a preferred material for chemical detection systems in analytical chemistry, biology, and the environmental sciences. However, it is often compromised with SU8, PDMS, or Parylene materials due to the sophisticated mask preparation requirements for wet etching of glass. Here, we report our efforts toward developing a photolithography-free laser-patterned hydrofluoric acid-resistant chromium-polyimide tape mask for rapid prototyping of microfluidic systems in glass...
January 2017: Journal of Micromechanics and Microengineering: Structures, Devices, and Systems
https://www.readbyqxmd.com/read/28531955/influence-of-sediment-chemistry-and-sediment-toxicity-on-macroinvertebrate-communities-across-99-wadable-streams-of-the-midwestern-usa
#6
Patrick W Moran, Lisa H Nowell, Nile E Kemble, Barbara J Mahler, Ian R Waite, Peter C Van Metre
Simultaneous assessment of sediment chemistry, sediment toxicity, and macroinvertebrate communities can provide multiple lines of evidence when investigating relations between sediment contaminants and ecological degradation. These three measures were evaluated at 99 wadable stream sites across 11 states in the Midwestern United States during the summer of 2013 to assess sediment pollution across a large agricultural landscape. This evaluation considers an extensive suite of sediment chemistry totaling 274 analytes (polycyclic aromatic hydrocarbons, organochlorine compounds, polychlorinated biphenyls, polybrominated diphenyl ethers, trace elements, and current-use pesticides) and a mixture assessment based on the ratios of detected compounds to available effects-based benchmarks...
May 17, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28531195/livestock-metabolomics-and-the-livestock-metabolome-a-systematic-review
#7
Seyed Ali Goldansaz, An Chi Guo, Tanvir Sajed, Michael A Steele, Graham S Plastow, David S Wishart
Metabolomics uses advanced analytical chemistry techniques to comprehensively measure large numbers of small molecule metabolites in cells, tissues and biofluids. The ability to rapidly detect and quantify hundreds or even thousands of metabolites within a single sample is helping scientists paint a far more complete picture of system-wide metabolism and biology. Metabolomics is also allowing researchers to focus on measuring the end-products of complex, hard-to-decipher genetic, epigenetic and environmental interactions...
2017: PloS One
https://www.readbyqxmd.com/read/28527356/exceptional-release-kinetics-and-cytotoxic-selectivity-of-oxidised-mwcnts-double-functionalised-with-doxorubicin-and-prostate-homing-peptide
#8
Vedran Milosavljevic, Ludmila Krejcova, Roman Guran, Hana Buchtelova, Dorota Wawrzak, Lukas Richtera, Zbynek Heger, Pavel Kopel, Vojtech Adam
Multiwall carbon nanotubes (MWCNTs) are among the frequently studied carbon materials, particularly because of their physical and chemical properties and high potential for application in materials chemistry, industry, and medicine. MWCNTs are very promising as transporters of bioactive molecules because of their π electrons and large surface area, which can be easily modified, mostly by the application of inorganic acids for the introduction of carboxylic moieties on the surface. In the present study, we designed an oxidised MWCNTs (oMWCNTs) transporter for the targeted delivery of doxorubicin (Dox)...
May 3, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28527183/analytical-methods-in-tracing-honey-authenticity
#9
Jelena Trifković, Filip Andrić, Petar Ristivojević, Etil Guzelmeric, Erdem Yesilada
Honey is a precious natural product that is marketed with a wide range of nutritional and medicinal properties. However, it is also a product subjected to frequent adulteration through mislabeling and mixing with cheaper and lower-quality honeys and various sugar syrups. In that sense, honey authentication regarding its genuine botanical and geographical origins, as well as the detection of any adulteration, is essential in order to protect consumer health and to avoid competition that could create a destabilized market...
May 19, 2017: Journal of AOAC International
https://www.readbyqxmd.com/read/28526341/preparation-and-characterization-of-amidated-derivatives-of-alginic-acid
#10
Tomáš Taubner, Milan Marounek, Andriy Synytsya
Alginic acid is a suitable material for modification to prepare new derivatives because of presence of its carboxyl groups. The high content of carboxyl groups over the entire length of its chain renders it an easily modifiable material with a possibility of achieving a high degree of substitution in the prepared derivatives. The salt of alginic acid (sodium alginate) is readily commercially available and is widely used in many branches of chemistry. Alginic acid was thus selected as the substrate for amidation...
May 17, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28521954/gas-chromatography-mass-spectrometry-strategies-for-the-accurate-and-sensitive-speciation-of-sulfur-dioxide-in-wine
#11
Vanesa Carrascon, Ignacio Ontañón, Mónica Bueno, Vicente Ferreira
Understanding the chemistry of wine oxidation requires the accurate and sensitive quantitative determination of the most important molecular species which SO2 can form. An analytical strategy based in three independent static headspace GC-MS determinations is proposed in order to obtain information about the total, nominally free and truly free levels of SO2. Nominally free forms are directly determined after sample acidulation, total forms require the previous incubation at 100°C, and truly free forms are determined after preconcentration of the headspace of the undisturbed sample in an alkaline solution...
May 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28518086/ptr-tof-ms-coupled-with-an-automated-sampling-system-and-tailored-data-analysis-for-food-studies-bioprocess-monitoring-screening-and-nose-space-analysis
#12
Vittorio Capozzi, Sine Yener, Iuliia Khomenko, Brian Farneti, Luca Cappellin, Flavia Gasperi, Matteo Scampicchio, Franco Biasioli
Proton Transfer Reaction (PTR), combined with a Time-of-Flight (ToF) Mass Spectrometer (MS) is an analytical approach based on chemical ionization that belongs to the Direct-Injection Mass Spectrometric (DIMS) technologies. These techniques allow the rapid determination of volatile organic compounds (VOCs), assuring high sensitivity and accuracy. In general, PTR-MS requires neither sample preparation nor sample destruction, allowing real time and non-invasive analysis of samples. PTR-MS are exploited in many fields, from environmental and atmospheric chemistry to medical and biological sciences...
May 11, 2017: Journal of Visualized Experiments: JoVE
https://www.readbyqxmd.com/read/28516280/optimization-of-an-ultrasound-assisted-derivatization-for-gc-ms-analysis-of-oxygenated-organic-species-in-atmospheric-aerosol
#13
Maria Chiara Pietrogrande, Francesco Manarini, José Benito Quintana, Rosario Rodil, Eugenia Villaverde-de-Sáa, Marco Visentin
A novel ultrasound-assisted derivatization followed by GC/MS analysis was developed for the quantification of oxygenated organic species in ambient aerosol. Derivatization parameters mostly influencing the analytical response were investigated, i.e., solvent type, reagent concentration, and reaction duration. Response surface methodology was used to design experiments and a quadratic model was utilized to predict the variables and establish the optimal conditions. The study was performed on standard solutions of 30 compounds representing the major classes of oxygenated compounds typically found in ambient aerosol, i...
May 18, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28508632/colloidally-assembled-zinc-ferrite-magnetic-beads-superparamagnetic-labels-with-high-magnetic-moments-for-mr-sensors
#14
Jooneon Park, Marc D Porter, Michael C Granger
Magnetic particles are widely used as labels in magnetoresistive (MR) sensors. To use magnetic particles as labels, several important characteristics should be considered, such as superparamagnetism, a high magnetic moment per particle (m), facile surface functionalization and biomolecule immobilization, colloidal stability, and analyte specificity. Described in this paper is the preparation of magnetic labels with a high m using colloidal assemblies of superparamagnetic zinc ferrite nanoparticles (ZFNPs, ~9 nm)...
May 16, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28507692/high-level-ab-initio-potential-energy-surface-and-dynamics-of-the-f-ch3i-sn2-and-proton-transfer-reactions
#15
Balázs Olasz, István Szabó, Gábor Czakó
Bimolecular nucleophilic substitution (SN2) and proton transfer are fundamental processes in chemistry and F(-) + CH3I is an important prototype of these reactions. Here we develop the first full-dimensional ab initio analytical potential energy surface (PES) for the F(-) + CH3I system using a permutationally invariant fit of high-level composite energies obtained with the combination of the explicitly-correlated CCSD(T)-F12b method, the aug-cc-pVTZ basis, core electron correlation effects, and a relativistic effective core potential for iodine...
April 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28507355/estimation-of-uncertainty-measurement-a-prerequisite-of-iso1589-accreditation-for-clinical-laboratories
#16
Sahar Iqbal, Aamir Ijaz, Shaheen Sharafat
OBJECTIVE: To estimate relative expanded uncertainty measurement of routine clinical chemistry analytes for international organisation for standardisation 15189 accreditation. METHODS: This cross-sectional study was conducted at Dow International Medical College, Karachi, from September 2013 to May 2014. During the process of international organisation for standardisation 15189 accreditation, measurement uncertainty was estimated for 13 clinical chemistry analytes using top-down approach...
May 2017: JPMA. the Journal of the Pakistan Medical Association
https://www.readbyqxmd.com/read/28503805/development-of-a-siyalon-glaze-for-improved-osteoconductivity-of-implantable-medical-devices
#17
Ryan M Bock, Elia Marin, Alfredo Rondinella, Francesco Boschetto, Tetsuya Adachi, Bryan J McEntire, B Sonny Bal, Giuseppe Pezzotti
The application of bioactive coatings onto orthopaedic appliances is commonly performed to compensate for the otherwise bioinert nature of medical devices and to improve their osseointegration. Calcium phosphates, hydroxyapatite (HAp), and bioglasses are commercially available for this purpose. Until recently, few other inorganic compounds have been identified with similar biofunctionality. However, silicon nitride (Si3 N4 ) has emerged as a new orthopaedic material whose unique surface chemistry also enhances osteoconductivity...
May 15, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28503802/electrospun-polyethersolfone-nanofibrous-membrane-as-novel-platform-for-protein-immobilization-in-microfluidic-systems
#18
Matin Mahmoudifard, Manouchehr Vossoughi, Sara Soudi, Masoud Soleimani
In the present study, the feasibility of electrospun polyethersolfone (PES) nanofibrous membrane as the solid substrate for microfluidic based immunoassays to enhance the density of immobilized antibody on the surface of membrane was assessed. Conversely, the efficacy of antibody immobilization was compared by two different strategies as 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC)/N-Hydroxysuccinimide (NHS) coupling chemistry and hydrophobic interaction. Compared to conventional immunoassays carried out in plates or gels, microfluidic based immunoassays grant a lot of advantages such as a consumption of little samples and reagents, shorter analysis time, and higher efficiency...
May 15, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
https://www.readbyqxmd.com/read/28502166/grouping-of-petroleum-substances-as-example-uvcbs-by-ion-mobility-mass-spectrometry-to-enable-chemical-composition-based-read-across
#19
Fabian Alexander Grimm, William K Russell, Yu-Syuan Luo, Yasuhiro Iwata, Weihsueh A Chiu, Tim Roy, Peter J Boogaard, Hans B Ketelslegers, Ivan Rusyn
Substances of Unknown or Variable composition, Complex reaction products, and Biological materials (UVCBs), including many refined petroleum products, present a major challenge in regulatory submissions under the EU Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) and US High Production Volume regulatory regimes. The inherent complexity of these substances, as well as variability in composition obfuscates detailed chemical characterization of each individual substance and their grouping for human and environmental health evaluation through read-across...
May 14, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28501196/calibration-transfer-between-different-analytical-methods
#20
Vitaly Panchuk, Dmitry Kirsanov, Ekaterina Oleneva, Valentin Semenov, Andrey Legin
The procedure for transfer of calibration models between different analytical methods is suggested. It is based on the direct standardization (DS) algorithm earlier suggested for data conversion between physically different instruments of the same type. As a result, multivariate regression models obtained e.g. for NIR spectroscopic measurements in one wavelength range can be successfully applied for predictions from the data obtained with another NIR spectrometer in another wavelength range. The performance of the suggested method was tested with two simulated and two real datasets...
August 1, 2017: Talanta
keyword
keyword
29343
1
2
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"