The last decade has seen widespread adoption of triple quadrupole-based inductively coupled plasma-tandem mass spectrometry (ICPMS/MS) technique using a collision/reaction cell in combination with a precell bandpass mass analyzer to measure isotopes otherwise masked by spectral interferences. High-precision isotope ratio analysis containing such isotopes would benefit from a similar capability on a multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) platform, but using a quadrupole-based precell mass analyzer for MC-ICPMS/MS has several limitations. To overcome these limitations, we developed a novel precell mass analyzer for MC-ICPMS/MS using sector field technology.
View Article and Find Full Text PDFWe document the utility for Rb-Sr dating of a one-of-a-kind tribrid mass spectrometer, 'Proteus', coupled to a UV laser ablation system. Proteus combines quadrupole mass-filter, collision cell and sector magnet with a multicollection inductively-coupled plasma mass spectrometer (CC-MC-ICPMS/MS). Compared to commercial, single collector, tribrid inductively-coupled plasma mass spectrometers (CC-ICPMS/MS) Proteus has enhanced ion transmission and offers simultaneous collection of all Sr isotopes using an array of Faraday cups.
View Article and Find Full Text PDFRationale: Magnesium is one of the most abundant elements in the earth's crust and in seawater. Fractionation of its stable isotopes has been shown to be a useful indicator of many geological, chemical, and biological processes. For example, biogenic carbonates display an ~5‰ range of δ Mg values, which is attributed to variable degrees of biological control on Mg ions during biomineralisation.
View Article and Find Full Text PDFThe introduction of rapid response laser ablation cells and sample transport technologies to laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) has enabled signal pulse durations for a single laser ablation shot of less than 10 ms. These developments have resulted in marked improvements in analytical throughput, resolution, and sensitivity vital for the generation of large, highly spatially resolved elemental maps. The focus on mapping, particularly bioimaging, has obscured the possibility of applying the sensitivity advantage of rapid response technologies to other LA-ICPMS applications, such as high-precision isotope ratio analysis on multicollector (MC) ICPMS.
View Article and Find Full Text PDFRationale: Li and Mg isotopes are increasingly used as a combined tool within the geosciences. However, established methods require separate sample purification protocols utilising several column separation procedures. This study presents a single-step cation-exchange method for quantitative separation of trace levels of Li and Mg from multiple sample matrices.
View Article and Find Full Text PDFRationale: Boron isotope ratios (δ B values) are used as a proxy for seawater paleo-pH, amongst several other applications. The analytical precision can be limited by the detection of low intensity ion beams from limited sample amounts. High-gain amplifiers offer improvements in signal/noise ratio and can be used to increase measurement precision and reduce sample amounts.
View Article and Find Full Text PDFFromm et al. and Vernier et al. suggest that their analyses of satellite measurements indicate that the main part of the Nabro volcanic plume from the eruption on 13 June 2011 was directly injected into the stratosphere.
View Article and Find Full Text PDFInhaled depleted uranium (DU) aerosols are recognised as a distinct human health hazard and DU has been suggested to be responsible in part for illness in both military and civilian populations that may have been exposed. This study aimed to develop and use a testing procedure capable of detecting an individual's historic milligram-quantity aerosol exposure to DU up to 20 years after the event. This method was applied to individuals associated with or living proximal to a DU munitions plant in Colonie New York that were likely to have had a significant DU aerosol inhalation exposure, in order to improve DU-exposure screening reliability and gain insight into the residence time of DU in humans.
View Article and Find Full Text PDFThe possibility of retrieving horizontal atmospheric structure from a series of limb images taken aboard a satellite is discussed and a maximum likelihood expectation maximization algorithm is developed. Examples of the retrieval of horizontal structure with this algorithm, for different S/N (signal-to-noise) ratios and different structures, are presented. It is shown that with this algorithm and even in the presence of substantial observational noise, a S/N equal to 10 for a single observation, it is possible to retrieve both horizontal and vertical atmospheric structure.
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