Search results for "icp"
showing 10 items of 139 documents
Forensic comparison of PVC tape backings using time resolved LA-ICP-MS analysis
2019
Abstract Adhesive tapes are common tools for criminal acts such as the construction of improvised explosive devices. Hence, tape samples can be used as evidence to link a suspect to a scene of crime or different crime scenes to each other. A set of 87 black electrical tapes was the subject of a study evaluating a LA-ICP-MS method for the characterization of tape backings regarding their elemental composition in a forensic context. LA-ICP-MS is a powerful tool in forensic investigations due to fast, quasi nondestructive analysis of small samples and detection or determination of elements up to the ultra-trace range. In this study, the development of a semiquantitative LA-ICP-MS method for fo…
New data on the exploitation of obsidian in the mediterranean basin: The harbour of pyrgi and the trade in neolithic age
2020
The contribution shows the first results of ongoing research on the origins and prehistoric assumptions of the well-known Etruscan and Roman harbour of Pyrgi, an ancient Ceretan harbour in southern Etruria. In the light of recent land and submarine investigations, traces of ancient frequentations and contacts dating back to the Neolithic era are emerging when the coastal morphology and environmental characteristics of the site were very different from the current ones. The Etruscan port of Pyrgi, which continues its historical history in Roman and Medieval times, appears as the heir of one or more landing points frequented perhaps already in the Middle Neolithic. As part of this contributio…
Latvijas šķirnes aitu vilnas ķīmiskā sastāva kvantitatīvā analīze un fizikāli-ķīmisko īpašību izpēte
2019
Voikiva V., zinātniskie vadītāji vadošais pētnieks, Dr. chem. Zariņš A. un docente, Dr. chem. Rudoviča V., konsultante pētniece, Mg. chem. Avotiņa L. Bakalaura darbs, 56 lappuses, 34 attēli, 5 tabulas, 50 literatūras avoti. Latviešu valodā. Bakalaura darba ietvaros pētīts Latvijā audzētu aitu vilnas elementu ķīmiskais sastāvs un fizikāli-ķīmiskās īpašības, lai novērtētu tās iespējamo pielietošanu degšanas procesa SEG gāzu un degšanas cieto izmešu filtros. Izmantotas vairākas fizikāli-ķīmiskās analīzes metodes, kā arī to kombinācijas, lai pēc iespējas precīzāk un detalizētāk varētu analizēt vilnas struktūru un termiskās iedarbības produktus pirms un pēc biomasas degšanas produktu sorbcijas.
Makro un mikroelementu sastopamības variācijas hibrīdapsēs
2020
Darbā tiek veikta hibrīdapses paraugu sagatavošana un analizēšana. Smago metālu un makroelementu koncentrācijas noteikšanai paraugos tiek lietots induktīvi saistītas plazmas masspektrometrs. Paraugu sagatavošanai tiek izmantota slapjā mineralizācija mikroviļņos.
Gaisa aerosolu daļiņu mērījumi iekštelpās un āra vidē
2016
Gaisa aerosolu daļiņu mērījumi iekštelpās un āra vidē. Ivanovs V., zinātniskā vadītāja Doc., Dr. ķīm. Osīte A. Bakalaura darbs, 36 lappuses, 19 attēli, 0 tabulas, 27 literatūras avoti. Darbs uzrakstīts latviešu valodā. Literatūras apskatā ir apkopota literatūra par gaisa piesārņojumu, aerosola daļiņu, tas veidošanas avotiem un analīzes metodēm. Veikti gaisa aerosolu koncentrāciju mērījumi, izmantojot putekļu monitoru Grimm EDM107. Aerosolu koncentrāciju mērījumi bija veikti iekštelpās un āra vidē raksturojot dažādu sadzīvē pielietotu degšanas procesu rezultātā radušos aerosolu daļiņu koncentrācijas. Kā arī bija veikta Rīgas pilsētvidē ņemtu aerosolu analīze ar induktīvi saistītās plazmas ma…
Uguņošanas laikā radušos aerosolu daļiņu sastāva analīze
2019
Literatūras apskatā apkopota informācija par aerosoliem un to pētīšanas metodēm, salūta epizožu laikā radīto gaisa piesārņojuma ietekmi gan cilvēka organismam, gan klimatam un iekārtām, kuras izmanto paraugu ņemšanā un analīzē. Darba eksperimentālajā daļā veikta gaisa aerosolu daļiņu ņemšana uguņošanas laikā un ikdienā, frakcionējot smalkās un rupjās aerosolu daļiņas. Smalkajām un rupjajām aerosolu daļiņām noteikta masas koncentrācija un metālisko elementu saturs, izmantojot ICP-MS un TXRF analīzes.
Determination of phosphorylation degrees in caseins by on-line gel electrophoresis coupled to ICP-SFMS
2007
The determination of the phosphorylation degree of proteins is essential in many biochemical fields. Besides mass spectrometric techniques elucidating the protein structure, ICP-MS has entered this research area as it provides excellent quantification capabilities. In this work the separation of the proteins has been carried out by gel electrophoresis on-line coupled to an ICP equipped with a double-focusing sector field-MS (ELEMENT 2). Based on the simultaneous detection of 32S+ and 31P+, this work presents an alternative approach to determining the phosphorylation degree of caseins. For the example of α- and β-casein the results obtained were in excellent agreement with the expected value…
Characterization and differentiation of rock varnish types from different environments by microanalytical techniques
2017
© 2017 Elsevier B.V. We investigated rock varnishes collected from several locations and environments worldwide by a broad range of microanalytical techniques. These techniques were selected to address the challenges posed by the chemical and structural complexity within the micrometer- to nanometer-sized structures in these geological materials. Femtosecond laser ablation-inductively coupled plasma-mass spectrometry (fs LA-ICP-MS), scanning transmission X-ray microscopy-near edge X-ray adsorption fine structure spectroscopy (STXM-NEXAFS) in combination with scanning electron microscopy (SEM) of focused ion beam (FIB) ultra-thin (100–200 nm) sections, conventional and polarization microscop…
A LA-ICP-MS STUDY OF CARBONATITES FROM FUERTEVENTURA, CANARY ISLAND
Carbonatites complexes are very rare in oceanic environments and in the Atlantic Ocean they can be only found at Cape Verde islands and Fuerteventura. Fuerteventura is the second largest island in the Canary Archipelago and is located on a transitional, continental to oceanic, crust. It consists essentially of Mesozoic sediments, submarine volcanic rocks, subaerial basaltic and trachytic series, ultramafic, mafic to felsic intrusives (clinopyroxenites, melteijites-ijolites, nepheline-monzogabbros, nepheline-sienites) and carbonatitic dike swarms (age 25 Ma). Carbonatite dike (Ca-carbonatites) mineralogy consists of calcite, aegirine-augite, albite, K-feldspar, biotite, apatite, Fe-Ti oxides…
(Supplement Table S2) Results of 230Th/U-dating
2016
We compared the suitability of two skeletal materials of the Atlantic brain coral Diploria strigosa for 230Th/U-dating: the commonly used bulk material comprising all skeletal elements and the denser theca wall material. Eight fossil corals of presumably Last Interglacial age from Bonaire, southern Caribbean Sea, were investigated, and several sub-samples were dated from each coral. For four corals, both the ages and the activity ratios of the bulk material and theca wall agree within uncertainty. Three corals show significantly older ages for their bulk material than for their theca wall material as well as substantially elevated 232Th content and (230Th/238U) ratios. The bulk material sam…