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1.
J. Miguel Vadillo M. Esther Gonzalez Isabel Carretero J. Javier Laserna 《Mikrochimica acta》1995,118(3-4):273-282
Micellar liquid chromatography (MLC) and capillary zone electrophoresis (CZE) have been evaluated for the analysis of twelve banned drugs in sport including diuretics and -blockers. In MLC, a sodium dodecylsulphate aqueous solution has been used as mobile phase using an octadecylsilica column. In CZE, a pH 8 buffer solution and a silica capillary have been employed. Parameters of retention and efficiency have been compared. Limits of detection with UV detection at 254 nm and relative standard deviations for atenolol, furosemide, nadolol, spironolactone and triamterene were established and compared in both techniques. Examples of direct urine injection into the separation systems are presented. Drugs overlapping in MLC are well resolved in CZE, while the opposite is true for a limited number of drugs. Some interferences from urine may arise in CZE. The selectivity of analysis would be greatly enhanced by using both techniques, which require only filtration as pre-treatment. 相似文献
2.
Vadillo JM Palanco S Romero MD Laserna JJ 《Analytical and bioanalytical chemistry》1996,355(7-8):909-912
The applicability of laser-induced breakdown spectrometry (LIBS) for surface analysis is presented in terms of its lateral and depth resolution. A pulsed N(2) laser at 337.1 nm (3.65 J/cm(2)) was used to irradiate solar cells employed for photovoltaic energy production. Laser produced plasmas were collected and detected using a charge-coupled device. An experimental device developed in the laboratory permits an exact synchronization of sample positioning using an XY motorized system with laser pulses. Multielement analysis with lateral resolution of up to 30 microm is feasible with the present system. Three-dimensional capabilities of the system are used for studies on the distribution of carbon impurities at the surface of the solar cells. 相似文献
3.
Space and time-resolved studies of laser induced plasmas in air at atmospheric pressure are presented. Photovoltaic solar cells have been used as samples. The second harmonic (532 nm) of a Nd : YAG laser at an irradiance of 18 x 10(12) W/cm(2) has been used. The precise focus of the beam allows a microanalysis at a 0.02 mm(2) surface area working in single-shot mode. The use of an intensified charge-coupled device (CCD) detector has allowed time-resolved studies in both imaging or spectroscopy modes. The two-dimensional capability of the CCD has enabled the study of atomic and ionic species distribution along the plume. Most data have been recorded using single-laser shot experiments. Spectral lines have been assigned to transitions in atomic components of the material under investigation in the neutral or ionic states of the corresponding atoms. Effects of delay in improving spectral resolution and some examples of spectral characterization of species as a function of its decay are shown. 相似文献
4.
Laser-induced breakdown spectroscopy (LIBS) in air at atmospheric pressure has been used to study four geological samples belonging to different structural families. Atomic emission spectra of vanadinite, pyrite, garnet and a type of quartz (compostela's quartz) are shown. The 532 nm line of a Nd:YAG laser at an irradiance of 18 x 10(11) W cm(-2) was used. The precise focus of the beam allowed microanalysis of a 0.02 mm(2) surface area working in single-laser shot mode. The use of an intensified gateable charge-coupled-device (CCD) detector permitted time-resolved studies. The spectral lines have been assigned to transitions in the neutral charge state of the corresponding atom of the material under investigation. The behavior of different transitions with time delay are shown. In experiments, minor components contained in several minerals have been detected. This fact has been used to demonstrate the applicability of the technique to characterize and identify similar minerals. 相似文献
5.
6.
José M. Vadillo I. Vadillo F. Carrasco J. J. Laserna 《Analytical and bioanalytical chemistry》1998,361(2):119-123
Laser-induced breakdown spectrometry (LIBS) has been applied to spatially locate several atomic species in speleothems taken from the Nerja’s Cave (Málaga, Spain). Spatial distribution profiles of Mg at 285.21 nm and Sr at 407.77 nm were obtained while the laser was rastered through different paths along the sample. These elements were selected due to their importance as palaeoclimatic indicators. The 532 nm output of a Nd:YAG laser was used to irradiate the samples and generate the plasma that was spectrally analyzed and detected by using an intensified CCD detector. The signals were normalized to the Ca line to minimize pulse-to-pulse fluctuations in the laser source. Several studies were carried out to check for the point-to-point heterogeneity of the natural speleothem. 相似文献
7.
J. M. Vadillo S. Palanco M. D. Romero J. J. Laserna 《Fresenius' Journal of Analytical Chemistry》1996,355(7-8):909-912
The applicability of laser-induced breakdown spectrometry (LIBS) for surface analysis is presented in terms of its lateral and depth resolution. A pulsed N2 laser at 337.1 nm (3.65 J/cm2) was used to irradiate solar cells employed for photovoltaic energy production. Laser produced plasmas were collected and detected using a charge-coupled device. An experimental device developed in the laboratory permits an exact synchronization of sample positioning using an XY motorized system with laser pulses. Multielement analysis with lateral resolution of up to 30 m is feasible with the present system. Three-dimensional capabilities of the system are used for studies on the distribution of carbon impurities at the surface of the solar cells. 相似文献
8.
We solve by a finite difference method a system of simultaneous non-linear partial differential equations which modelizes the transfer of heat and mass when a fluid evaporates from the hot wall and condenses on the cold wall of an upright rectangular cavity. The need to verify a certain condition associating the physical parameters of the fluid for the existence of steady state solutions is proved. 相似文献
9.
Pereyra P. López Herrera M. E. Palacios D. Viloria T. Vadillo E. Pérez B. Sajo-Bohus L. 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(2):609-614
Journal of Radioanalytical and Nuclear Chemistry - Nuclear track methodology (NTM), is employed to analyze PADC detectors response to different energetic ion beams. Due to the passive device... 相似文献
10.
Téllez H Vadillo JM Laserna JJ Chater RJ McPhail DS 《Analytical and bioanalytical chemistry》2012,402(7):2277-2285
Patination of metals has been used for decorative or protective purposes, and several methods aimed to create coloured films
on metal surfaces have been developed. This work describes a multi-analytical approach to characterize artificial blue patinas
created on mild steel substrates by means of traditional recipes and methods for colouring ancient objects and artefacts.
We suggest the combined use of secondary ion mass spectrometry, focused ion beam, X-ray diffraction spectroscopy, white light
interferometry and reflectance spectroscopy to characterize blue patinas on steel substrates and to investigate the relationship
between the developed colour and the patina layer microstructure and composition. Therefore, the analysis of the oxide films
produced by either thermal or chemical colouring methods has been successfully performed, providing information about the
film morphology, the surface composition and in-depth elemental distribution within the coloured layers, and the origin of
the colour developed on the surface. 相似文献