WorldWideScience

Sample records for spectrochemistry

  1. European winter conference on plasma spectrochemistry 2009. Book of abstracts

    International Nuclear Information System (INIS)

    Francesconi, K.; Goessler, W.; Kuehnelt, D.; Raber, G.; Tuider, A.; Knapp, G.; Kuczewski, B.; Wiltsche, H.; Eberl, M.

    2009-01-01

    The oral and poster presentations were dedicated to recent developments in the following areas: fundamental plasma spectrochemistry; instrumentation: sources and spectrometers, sample introduction and sample preparation; laser-assisted plasma spectrochemistry; stable isotope measurements and isotope dilution analysis; certified reference materials; speciation analysis, and its applications in various fields such as clinical, environmental, biological, forensic, industrial, geological, mining/exploration, advanced materials. This book of abstracts contains their summaries and those contributions which are in the INIS subject scope are indexed individually. (nevyjel)

  2. 13. Italian-Hungarian Symposium on spectrochemistry: environmental contamination and food safety. Book of Abstract

    International Nuclear Information System (INIS)

    Bottoni, P.; Caroli, S.

    2008-01-01

    This edition of the Symposium focuses primarily on the impact of environmental pollution on food safety. With about 90 contributions, equally distributed between oral and poster presentations, some of the major challenges posed by anthropic activities to food commodities are discussed. The role of modern analytical techniques in this context is highlighted particularly as regards the importance of reliable experimental information in the decision-making process. The Symposium features seven oral sessions, devoted, respectively, to basic research, manufacturers, water, soil and sediment, atmosphere, food and research in Antarctica. Presentations in the poster sessions are grouped likewise. The variety of issues dealt with in this conference give ample evidence of the progress made so far by analytical sciences in this field and set the stage for further innovative research [it

  3. A logical way through the limits of quantitation in inductively coupled plasma spectrochemistry

    International Nuclear Information System (INIS)

    Mermet, J.M.; Granier, G.; Fichet, P.

    2012-01-01

    The limit of quantitation (LOQ) is a crucial parameter in quantitative analysis. Besides the classical “10 s B approach”, other concepts have been previously described based on the limitation resulting from the calibration procedure, namely from the prediction bands and the uncertainty calibration. Because of the difficulty of obtaining a reliable value of the blank standard deviation, this approach was replaced by the study of the %RSD of the net signal as a function of the concentration. Recently described, the so-called accuracy profile method, accuracy being the contribution of both the trueness and the precision, allows the analyst to define a validity domain, the lowest point acting as a limit of quantitation. The aim of this work was to determine these various limits of quantitation, including that from the accuracy profile, to compare them, and to study the parameters that can influence their values. It was concluded that the LOQ deduced from the accuracy profile is a realistic one. Its value is mainly influenced by the calibration procedure, particularly when a weighting procedure is used. A 1/y weighting factor, y being the analyte line intensity, seems to be an efficient compromise for calibration. - Highlights: ► An analytical method is defined by its accuracy, i.e. both trueness and precision. ► A limit of quantitation should be based on an accuracy criterion and not on precision. ► The accuracy as a function of an analyte concentration is an accuracy profile. ► Profile-based tolerance intervals define a validity domain. ► The lowest concentration of this domain corresponds to a limit of quantitation.

  4. Potential of accuracy profile for method validation in inductively coupled plasma spectrochemistry

    International Nuclear Information System (INIS)

    Mermet, J.M.; Granier, G.

    2012-01-01

    Method validation is usually performed over a range of concentrations for which analytical criteria must be verified. One important criterion in quantitative analysis is accuracy, i.e. the contribution of both trueness and precision. The study of accuracy over this range is called an accuracy profile and provides experimental tolerance intervals. Comparison with acceptability limits fixed by the end user defines a validity domain. This work describes the computation involved in the building of the tolerance intervals, particularly for the intermediate precision with within-laboratory experiments and for the reproducibility with interlaboratory studies. Computation is based on ISO 5725‐4 and on previously published work. Moreover, the bias uncertainty is also computed to verify the bias contribution to accuracy. The various types of accuracy profile behavior are exemplified with results obtained by using ICP-MS and ICP-AES. This procedure allows the analyst to define unambiguously a validity domain for a given accuracy. However, because the experiments are time-consuming, the accuracy profile method is mainly dedicated to method validation. - Highlights: ► An analytical method is defined by its accuracy, i.e. both trueness and precision. ► The accuracy as a function of an analyte concentration is an accuracy profile. ► Profile basic concepts are explained for trueness and intermediate precision. ► Profile-based tolerance intervals have to be compared with acceptability limits. ► Typical accuracy profiles are given for both ICP-AES and ICP-MS techniques.

  5. 13. Italian-Hungarian Symposium on spectrochemistry: environmental contamination and food safety. Book of Abstract; 13. Simposio italo-ungherese di spettrochimica: contaminazione ambientale e sicurezza alimentare

    Energy Technology Data Exchange (ETDEWEB)

    Bottoni, P [Department of Environment and Primary Prevention, Istituto Superiore di Sanita, Rome (Italy); Caroli, S [Department of Food Safety and Veterinary Public Health, Istituto Superiore di Sanita, Rome (Italy)

    2008-07-01

    This edition of the Symposium focuses primarily on the impact of environmental pollution on food safety. With about 90 contributions, equally distributed between oral and poster presentations, some of the major challenges posed by anthropic activities to food commodities are discussed. The role of modern analytical techniques in this context is highlighted particularly as regards the importance of reliable experimental information in the decision-making process. The Symposium features seven oral sessions, devoted, respectively, to basic research, manufacturers, water, soil and sediment, atmosphere, food and research in Antarctica. Presentations in the poster sessions are grouped likewise. The variety of issues dealt with in this conference give ample evidence of the progress made so far by analytical sciences in this field and set the stage for further innovative research. [Italian] Questa edizione del Simposio e dedicata soprattutto alle conseguenze della contaminazione ambientale sulla sicurezza degli alimenti. Alcune delle sfide piu rilevanti poste dalle attivita umane alla integrita dei prodotti alimentari sono discusse in circa 90 contributi, equamente distribuiti tra relazioni orali e poster. Vengono particolarmente messe in luce l'importanza delle attuali tecniche analitiche per produrre informazioni sperimentali attendibili e la rilevanza di queste ultime nel processo decisionale. Le sette sessioni orali sono dedicate, rispettivamente, alla ricerca di base, ai costruttori di strumentazione, alle acque, ai suoli e sedimenti, all'atmosfera, agli alimenti ed alla ricerca in Antartide. Le presentazioni poster si articolano in modo analogo. L'ampiezza dei temi esposti dimostra concretamente l'innovazione ad oggi apportata in questo settore dalle scienze analitiche e pone le basi per ricerche ancora piu avanzate.

  6. Detection of Indistinct Fe-N Stretching Bands in Iron(V) Nitrides by Photodissociation Spectroscopy

    Czech Academy of Sciences Publication Activity Database

    Andris, E.; Navrátil, R.; Jašík, J.; Sabenya, G.; Costas, M.; Srnec, Martin; Roithová, J.

    2018-01-01

    Roč. 24, č. 20 (2018), s. 5078-5081 ISSN 1521-3765 R&D Projects: GA ČR(CZ) GJ15-10279Y Institutional support: RVO:61388955 Keywords : photodissociation spectrochemistry * infrared spectra * DFT Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry

  7. Determination of carboxylic acids, carbohydrates and metals in different tomato cultivars by HPLC-ICP-AES in a single chromatographic run

    OpenAIRE

    Paredes Paredes, Eduardo; Maestre, Salvador E.; Prats Moya, Soledad; Todolí Torró, José Luis

    2007-01-01

    Póster presentado en European Winter Conference on Plasma Spectrochemistry 2007, 18-23 February 2007, Taormina, Italy The determination of carbohydrates, carboxylic acids and metals is a subject of great interest in the field of food science because their presence and concentration can influence on food quality. Besides the study of the profiles of these compounds can permit the discrimination between different varieties of a product. Unfortunately, the usually employed chromatograph...

  8. A brief history of laser-induced breakdown spectroscopy: From the concept of atoms to LIBS 2012

    International Nuclear Information System (INIS)

    Radziemski, Leon; Cremers, David

    2013-01-01

    LIBS did not appear de novo in 1962, but was built upon accomplishments of the past. These started with very old concepts of indivisible units (atomos), chemical and physical experiments and theoretical advances that took place in the late 19th and early 20th centuries, the development of the laser, the discovery of gas breakdown, and the realization of the application to spectrochemistry. We sketch the historical developments and focus as well on the advances in LIBS methodology and instrumentation over the past 50 years, culminating with a synopsis of the LIBS 2012 Conference in Luxor, Egypt

  9. Ligands and modifiers in vitreous materials the spectroscopy of condensed systems

    CERN Document Server

    Margaryan, Alfred

    1999-01-01

    The study of the effect of ligand and modifier ions on the spectroscopic properties of dn or fn elements in vitreous materials is important for the development of controllable lasers and amplifiers. The spectroscopic characteristics of inorganic compounds of transition elements and their solutions are well understood theoretically in the spectrochemistry of complexes, but developments for vitreous materials in these conditions have not been well documented. This book fills the gap by applying the ligand field theory of solid materials to the vitreous state, and presenting the data obtained fro

  10. A brief history of laser-induced breakdown spectroscopy: From the concept of atoms to LIBS 2012

    Energy Technology Data Exchange (ETDEWEB)

    Radziemski, Leon, E-mail: ljrbwr@comcast.net [Tucson, AZ (United States); Cremers, David [Applied Research Associates Inc., Albuquerque, NM (United States)

    2013-09-01

    LIBS did not appear de novo in 1962, but was built upon accomplishments of the past. These started with very old concepts of indivisible units (atomos), chemical and physical experiments and theoretical advances that took place in the late 19th and early 20th centuries, the development of the laser, the discovery of gas breakdown, and the realization of the application to spectrochemistry. We sketch the historical developments and focus as well on the advances in LIBS methodology and instrumentation over the past 50 years, culminating with a synopsis of the LIBS 2012 Conference in Luxor, Egypt.

  11. Excited-State Dynamics of Oxyluciferin in Firefly Luciferase

    KAUST Repository

    Snellenburg, Joris J.

    2016-11-23

    The color variations of light emitted by some natural and mutant luciferases are normally attributed to collective factors referred to as microenvironment effects; however, the exact nature of these interactions between the emitting molecule (oxyluciferin) and the active site remains elusive. Although model studies of noncomplexed oxyluciferin and its variants have greatly advanced the understanding of its photochemistry, extrapolation of the conclusions to the real system requires assumptions about the polarity and proticity of the active site. To decipher the intricate excited-state dynamics, global and target analysis is performed here for the first time on the steady-state and time-resolved spectra of firefly oxyluciferin complexed with luciferase from the Japanese firefly (Luciola cruciata). The experimental steady-state and time resolved luminescence spectra of the oxyluciferin/luciferase complex in solution are compared with the broadband time-resolved firefly bioluminescence recorded in vivo. The results demonstrate that de-excitation of the luminophore results in a complex cascade of photoinduced proton transfer processes and can be interpreted by the pH dependence of the emitted light. It is confirmed that proton transfer is the central event in the spectrochemistry of this system for which any assignment of the pH dependent emission to a single chemical species would be an oversimplification.

  12. Excited-State Dynamics of Oxyluciferin in Firefly Luciferase

    KAUST Repository

    Snellenburg, Joris J.; Laptenok, Sergey P.; DeSa, Richard J.; Naumov, Pance; Solntsev, Kyril M.

    2016-01-01

    The color variations of light emitted by some natural and mutant luciferases are normally attributed to collective factors referred to as microenvironment effects; however, the exact nature of these interactions between the emitting molecule (oxyluciferin) and the active site remains elusive. Although model studies of noncomplexed oxyluciferin and its variants have greatly advanced the understanding of its photochemistry, extrapolation of the conclusions to the real system requires assumptions about the polarity and proticity of the active site. To decipher the intricate excited-state dynamics, global and target analysis is performed here for the first time on the steady-state and time-resolved spectra of firefly oxyluciferin complexed with luciferase from the Japanese firefly (Luciola cruciata). The experimental steady-state and time resolved luminescence spectra of the oxyluciferin/luciferase complex in solution are compared with the broadband time-resolved firefly bioluminescence recorded in vivo. The results demonstrate that de-excitation of the luminophore results in a complex cascade of photoinduced proton transfer processes and can be interpreted by the pH dependence of the emitted light. It is confirmed that proton transfer is the central event in the spectrochemistry of this system for which any assignment of the pH dependent emission to a single chemical species would be an oversimplification.

  13. Development of atomic spectroscopy methods in geological institutes of Faculty of Natural Sciences Comenius University and Slovak Academy of Science

    International Nuclear Information System (INIS)

    Medved, E.

    1998-01-01

    Development of atomic spectrochemistry methods in Geological Institute of Faculty of Natural Sciences, Comenius University (GI FNS CU) is connected with its establishment in 1957. Its instrumental equipment and location resulted from the already existing Laboratory in the Chair for Mineralogy and Crystallography of FNS CU. In Geological Institute of Slovak Academy of Science (GI SAS) the development of atomic spectroscopy methods started later, only since 1963, when the Member of Academy, Prof. RNDr. B. Cambel, DrSc. became its director. In both institutes the methods of atomic emission spectrography were used as first. A new quality in the development started since 1969 when the Institutes moved to common buildings in Petrzalka (Bratislava), the first atomic absorption spectrometers were acquired and the Institutes were 'strengthened' by coming of Prof. Ing. E. Plsko, DrSc. In the following years the Institutes started to collaborate with some other organisations which were equipped with new facilities, e.g. in 1975 with X-ray fluorescence spectrometer, electron microprobe and in 1985 with inductively coupled plasma atomic emission spectrometer. This enabled to improve essentially the quality of research activities of both institutes in the chemical characterisation of geological materials, as well as in pedagogical work (students practice, diploma works and dissertations). In the present time characterized by new economic conditions a reduction of GI SAS laboratory activities has been realised. The laboratories of the GI FNS CU have, thanks to their director Ing. V. Stresko, PhD. shown also hence-forward a rich research, pedagogical and society activities what can be documented by numerous publications, citations, obtained awards, representations in professional societies and commissions, local and foreign advisory boards, accreditation boards etc. (author)

  14. Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid microvolume samples.

    Science.gov (United States)

    Schaper, J Niklas; Pfeuffer, Kevin P; Shelley, Jacob T; Bings, Nicolas H; Hieftje, Gary M

    2012-11-06

    One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads can quench the afterglow and, thus, the formation of reagent ions. As a result, the analysis of liquid samples is preferably carried out by analyzing dried residues or by desorbing small amounts of liquid samples directly from the liquid surface. In the former case, reproducibility of sample introduction is crucial if quantitative results are desired. In the present study, introduction of liquid samples as very small droplets helps overcome the issues of sample positioning and reduced levels of solvent intake. A recently developed "drop-on-demand" (DOD) aerosol generator is capable of reproducibly producing very small volumes of liquid (∼17 pL). In this paper, the coupling of FAPA-MS and DOD is reported and applications are suggested. Analytes representing different classes of substances were tested and limits of detections were determined. Matrix tolerance was investigated for drugs of abuse and their metabolites by analyzing raw urine samples and quantification without the use of internal standards. Limits of detection below 2 μg/mL, without sample pretreatment, were obtained.