Uranium Micro-isotopic Analysis of Weathered Rock by a Sensitive High Resolution Ion Microprobe (SHRIMP II)

1998 ◽  
Vol 82 (s1) ◽  
Author(s):  
Tsutomu Sato ◽  
Nobuyuki Yanase ◽  
Ian S. Williams ◽  
William Compston ◽  
Myint Zaw ◽  
...  
Keyword(s):  
High Resolution ◽  
Isotopic Analysis ◽  
Ion Microprobe ◽  
Weathered Rock

Conodonts and the Paleoclimatological and Paleoecological Applications of Phosphate Δ18O Measurements

2012 ◽  
Vol 18 ◽  
pp. 69-84 ◽  
Author(s):  
Kenneth G. MacLeod
Keyword(s):  
High Resolution ◽  
Isotopic Composition ◽  
Tooth Enamel ◽  
Isotopic Analysis ◽  
Isotopic Ratios ◽  
Ion Microprobe ◽  
Growth Series ◽  
Diagenetic Alteration ◽  
Oxygen Isotopic ◽  
Oxygen Isotopic Analysis

Oxygen isotopic analysis of the phosphate in bioapatite has become a standard paleoclimatological tool with results documented in a rapidly expanding literature. Phosphate-based measurements are particularly important for samples where carbonates preservation is suspect (as is the case for many Paleozoic sites). Important analytical and observational advances that have fueled the expansion of phosphate-based studies include: 1) Oxygen isotopic ratios of biogenic apatite can be measured on small enough samples (≥ ~300 μg), quickly enough, cheaply enough, and accurately enough to permit meaningful high resolution paleoclimatic studies of trends through time, along spatial transects, and/or among taxa, 2) biogenic apatite is precipitated in approximate equilibrium with ambient waters and thus records the interplay of temperature and the isotopic composition of the water in which a sample grew, 3) tooth enamel and conodont crown material are quite resistant to diagenetic alteration and are preferred targets for both paleotemperature and paleoecological studies, 4) Paleozoic conodont δ18O records seem to provide robust paleotemperature information on time scales ranging from thousands of years to 100's of millions of years, and generation of increasingly refined paleotemperature records from this diagenetically resistant phase is likely to continue to be a useful field of study, 5) paleoenvironmental variations in δ18O values of seawater have been documented (e.g., differences between glacial and interglacial oceans), but whether and by how much the δ18O value of the hydrosphere may have increased since the Cambrian remains unresolved, and 6) differences in δ18O values among conodont taxa are increasingly well documented and, coupled with the potential to study growth series using ion microprobe techniques, are providing novel perspectives on and important tests of conodont paleoecology.

scholarly journals Isotope analysis of highly enriched “silicon-28” by high-resolution inductively coupled plasma mass spectrometry using an internal standard

2021 ◽  
Vol 25 (2) ◽  
pp. 98-109
Author(s):  
P. A. Otopkova ◽  
◽  
A. M. Potapov ◽  
A. I. Suchkov ◽  
A. D. Bulanov ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Matrix Element ◽  
High Resolution ◽  
Inductively Coupled Plasma ◽  
Internal Standard ◽  
Isotopic Analysis ◽  
Random Component ◽  
Inductively Coupled ◽  
The Matrix ◽  
Plasma Mass Spectrometry

In order to study the isotopic effects in semiconductor materials, single crystals of high chemical and isotopic purity are required. The reliability of the obtained data on the magnitude and the direction of isotopic shifts depends on the accuracy of determining the concentration of all stable isotopes. In the isotopic analysis of enriched “silicon-28” with a high degree of enrichment (> 99.99%), it is necessary to determine the impurities of 29Si and 30Si isotopes at the level of 10-3 ¸ 10-5 at. %. At this concentration level, these isotopes can be considered as impurities. It is difficult to achieve high measurement accuracy with simultaneous registration of the main and “impurity” isotopes in such a wide range of concentrations. The registration of analytical signals of silicon isotopes must be carried out in the solutions with different matrix concentrations. The use of the solutions with the high concentration of the matrix element requires the introduction of corrections for matrix noise and the drift of the instrument sensitivity during the measurement. It is possible to reduce the influence of the irreversible non-spectral interference and sensitivity drift by using the method of internal standardization. The inconsistency of the literature data on the selection criteria for the internal standard required studying the behavior of the signals of the “candidates for the internal standard” for the ELEMENT 2 single-collector high-resolution inductively coupled plasma mass spectrometer on the matrix element concentration and the nature of the solvent, as well as on the solution nebulizing time. Accounting for the irreversible non-spectral matrix noise and instrumental drift in isotopic analysis of enriched “silicon-28” and initial 28SiF4 by inductively coupled plasma mass spectrometry had allowed us to reduce by 3-5 times the random component and by more than an order of magnitude the systematic component of the measurement error in comparison with the external standard method. This made it possible to carry out, with sufficient accuracy, the operational control of the isotopic composition of enriched “silicon-28”, both in the form of silicon tetrafluoride and polycrystalline silicon obtained from it, using a single serial device in the range of isotopic concentrations 0.0001–99.999%.

scholarly journals Sensitive High Resolution Ion Microprobe (SHRIMP IIe/MC) of the Institute of Geosciences of the University of São Paulo, Brazil: analytical method and first results

2014 ◽  
Vol 14 (3) ◽  
pp. 3-18 ◽  
Author(s):  
Kei Sato ◽  
Colombo Celso Gaeta Tassinari ◽  
Miguel Angelo Stipp Basei ◽  
Oswaldo Siga Júnior ◽  
Artur Takashi Onoe ◽  
...  
Keyword(s):  
High Resolution ◽  
Analytical Method ◽  
Sao Paulo ◽  
São Paulo ◽  
Ion Microprobe ◽  
First Results ◽  
The University

scholarly journals Near-highway aerosol and gas-phase measurements in a high-diesel environment

2015 ◽  
Vol 15 (8) ◽  
pp. 4373-4387 ◽  
Author(s):  
H. L. DeWitt ◽  
S. Hellebust ◽  
B. Temime-Roussel ◽  
S. Ravier ◽  
L. Polo ◽  
...  
Keyword(s):  
High Resolution ◽  
Traffic Congestion ◽  
Isotopic Analysis ◽  
Organic Aerosol ◽  
Diesel Emissions ◽  
Vehicular Emissions ◽  
Low Oxygen ◽  
Atmospheric Measurements ◽  
Passenger Cars ◽  
Aerosol Mass

Abstract. Diesel-powered passenger cars currently outnumber gasoline-powered cars in many countries, particularly in Europe. In France, diesel cars represented 61% of light duty vehicles in 2011 and this percentage is still increasing (French Environment and Energy Management Agency, ADEME). As part of the September 2011 joint PM-DRIVE (Particulate Matter – DiRect and Indirect on-road Vehicular Emissions) and MOCOPO (Measuring and mOdeling traffic COngestion and POllution) field campaign, the concentration and high-resolution chemical composition of aerosols and volatile organic carbon species were measured adjacent to a major urban highway south of Grenoble, France. Alongside these atmospheric measurements, detailed traffic data were collected from nearby traffic cameras and loop detectors, which allowed the vehicle type, traffic concentration, and traffic speed to be quantified. Six aerosol age and source profiles were resolved using the positive matrix factorization model on real-time high-resolution aerosol mass spectra. These six aerosol source/age categories included a hydrocarbon-like organic aerosol (HOA) commonly associated with primary vehicular emissions, a nitrogen-containing aerosol with a diurnal pattern similar to that of HOA, oxidized organic aerosol (OOA), and biomass burning aerosol. While quantitatively separating the influence of diesel from that of gasoline proved impossible, a low HOA : black carbon ratio, similar to that measured in other high-diesel environments, and high levels of NOx, also indicative of diesel emissions, were observed. Although the measurement site was located next to a large source of primary emissions, which are typically found to have low oxygen incorporation, OOA was found to comprise the majority of the measured organic aerosol, and isotopic analysis showed that the measured OOA contained mainly modern carbon, not fossil-derived carbon. Thus, even in this heavily vehicular-emission-impacted environment, photochemical processes, biogenic emissions, and aerosol oxidation dominated the overall organic aerosol mass measured during most of the campaign.

Aspects of high resolution imaging with a scanning ion microprobe

1988 ◽  
Vol 24 (2-3) ◽  
pp. 97-113 ◽  
Author(s):  
R. Levi-Setti ◽  
J.M. Chabala ◽  
Y.L. Wang
Keyword(s):  
High Resolution ◽  
High Resolution Imaging ◽  
Ion Microprobe ◽  
Resolution Imaging
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