Search results for "mass [excited state]"
showing 10 items of 5250 documents
Determination of mercury at picogram level in natural waters with inductively coupled plasma mass spectrometry by using 3D printed metal scavengers
2019
The determination of ultra-trace concentrations of Hg in natural water samples via preconcentration using 3D printed metal scavenger technique followed by inductively coupled plasma mass spectrometry (ICP-MS) was developed. The determination of Hg in certified reference material ERM-CA615 (groundwater) was performed with high accuracy and precision resulting in recovery of 100 ± 3% and RSD <2.5%, respectively. Selective laser sintering (SLS) 3D printing was used to fabricate the scavengers using a mixture of polyamide-12 powder with thiol-functionalized silica. The preconcentration procedure is based on the adsorption of Hg on the scavenger and followed by elution of the preconcentrated Hg …
Varying chiral ratio of Pinic acid enantiomers above the Amazon rainforest
2023
Chiral chemodiversity plays a crucial role in biochemical processes such as insect and plant communication. However, the vast majority of organic aerosol studies do not distinguish between enantiomeric compounds in the particle phase. Here we report chirally specified measurements of secondary organic aerosol (SOA) at the Amazon Tall Tower Observatory (ATTO) at different altitudes during three measurement campaigns at different seasons. Analysis of filter samples by liquid chromatography coupled to mass spectrometry (LC-MS) has shown that the chiral ratio of pinic acid (C9H14O4) varies with increasing height above the canopy. A similar trend was recently observed for the gas-phase precursor…
Formation of 3-methyl-1,2,3-butanetricarboxylic acid via gas phase oxidation of pinonic acid – a mass spectrometric study of SOA aging
2012
Abstract. This paper presents the results of mass spectrometric investigations of the OH-initiated oxidative aging of α-pinene SOA under simulated tropospheric conditions at the large aerosol chamber facility AIDA, Karlsruhe Institute of Technology. In particular, the OH-initiated oxidation of pure pinic and pinonic acid, two well-known oxidation products of α-pinene, was investigated. Two complementary analytical techniques were used, on-line atmospheric pressure chemical ionization/mass spectrometry (APCI/MS) and filter sampling followed by liquid chromatography/mass spectrometry (LC/ESI-MS). The results show that 3-methyl-1,2,3-butanetricarboxylic acid (MBTCA), a very low volatile α-pine…
Nanoparticles in the Biological Context: Surface Morphology and Protein Corona Formation
2020
Small 16(39), 2002162 (2020). doi:10.1002/smll.202002162
The maximum carbonyl ratio (MCR) as a new index for the structural classification of secondary organic aerosol components
2021
RATIONALE Organic aerosols (OA) account for a large fraction of atmospheric fine particulate matter and thus are affecting climate and public health. Elucidation of the chemical composition of OA is the key for addressing the role of ambient fine particles at the atmosphere-biosphere interface and mass spectrometry is the main method to achieve this goal. METHODS High-resolution mass spectrometry (HRMS) is on its way to becoming one of the most prominent analytical techniques, also for the analysis of atmospheric aerosols. The combination of high mass resolution and accurate mass determination allows the elemental compositions of numerous compounds to be easily elucidated. Here a new parame…
Design, characterization, and first field deployment of a novel aircraft-based aerosol mass spectrometer combining the laser ablation and flash vapor…
2021
In this paper, we present the design, development, and characteristics of the novel aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols; ERC – European Research Council) and selected results from the first airborne field deployment. The instrument combines two well-established methods of real-time in situ measurements of fine particle chemical composition. The first method is the laser desorption and ionization technique, or laser ablation technique, for single-particle mass spectrometry (here with a frequency-quadrupled Nd:YAG laser at λ = 266 nm). The second method is a combination of thermal particle desorption, also called flash vaporization, and electro…
Thermomineral waters of Greece: geochemical characterization
2020
El constitucionalismo democrático y social : orígenes y características distintivas
2020
The paper aims to reconstruct the doctrinal evolution of the juridical thought in the transition from liberal constitutionalism - identifiable with the nineteenth-century theories of the "rule of law" - to democratic-social constitutionalism that inspires and shapes the "Welfare State". In short, democratic-social constitutionalism can be viewed as the fundamental core of the social pact through which the European and Western civilisation manages to provide a democratic alternative to the disintegration of the liberal states. The main features of the new constitutionalism will be analyzed by focusing on what, in our opinion, can be considered its main “pillars”.
Patients' and physicians' preferences for type 2 diabetes mellitus treatments in Spain and Portugal: a discrete choice experiment.
2015
Objective: To assess Spanish and Portuguese patients' and physicians' preferences regarding type 2 diabetes mellitus (T2DM) treatments and the monthly willingness to pay (WTP) to gain benefits or avoid side effects. Methods: An observational, multicenter, exploratory study focused on routine clinical practice in Spain and Portugal. Physicians were recruited from multiple hospitals and outpatient clinics, while patients were recruited from eleven centers operating in the public health care system in different autonomous communities in Spain and Portugal. Preferences were measured via a discrete choice experiment by rating multiple T2DM medication attributes. Data were analyzed using the cond…
Religious-Philosophical Articles, XXXIII
2022
Žurnāla “Reliģiski-filozofiski raksti” XXXIII laidiens veltīts Latvijas sabiedrības vērtību analīzei salīdzinošā perspektīvā. Ņemot vērā vērtību jēdziena daudzdimensionālo raksturu, vērtību apraksts, analīze un klasifikācija visos laikos ir izraisījusi diskusijas, strīdus un pat konfliktus. Ideja veidot speciālu žurnāla numuru nolūkā veicināt teorētisko un empīrisko zināšanu attīstību par vērtībām Latvijā, aicinot sociālo un humanitāro zinātņu pētniekus dalīties ar jaunākajiem pētījumiem un atziņām šajā jomā, dzima projekta “Vērtību maiņa nestabilos apstākļos: sabiedrības saliedētība un neoliberālais ētoss” īstenošanas laikā. Pētnieciskā projekta tiešais mērķis bija sniegt jaunu salīdzinošu…