The Nu AttoM is a double-focusing, high-resolution magnetic sector mass spectrometer. The instrument is designed to provide precise and accurate isotope ratio analysis and elemental analysis of most elements in solution or in situ down to sub-ppt levels (best RSDs at about 250 ppt). Our Nu AttoM is a precursor to the current Nu AttoM ES, featured here.
The AttoM’s detector system gives it a large dynamic range, and its electrostatic scanning capability has the widest range in its class. One of the main advantages of the AttoM is its high signal sensitivity. For example, as low as 0.2 ng of Pb is needed for a single Pb analysis. Two low-resolution deflector scan modes, either peak jumping or peak scanning, can be performed over a limited mass range, up to 40% relative mass. The LinkScan mode, which combines the fast magnet scan with the unique deflector optics, is useful for applications where time-resolved analyses are required, such as for laser ablation.
The Nu AttoM was installed in PCIGR’s nUBC lab in September 2014. Recent applications include Pb isotope analyses in seawater and ice, honey and fish, and trace element analysis in rocks (e.g., Fourny et al., 2016; Smith et al., 2019; Li et al., 2020).
At PCIGR, the Nu AttoM can be connected to the CETAC Aridus II™ Desolvating Nebulizer System or the ESI Apex Desolvating Nebulizer System to increase the sensitivity of the signals, and to reduce oxide and hydride interference and matrix effects.
The Nu AttoM is also connected to the Excimer Laser Ablation System RESOlution M-50-LR at PCIGR. Split-stream LA-ICP-MS is possible by coupling both the Nu AttoM and the Agilent 7700x to the same laser ablation system. This technique allows for the simultaneous measurement of isotope ratios and trace element concentrations on the same sample run.
The Thermo Scientific Element 2, a sector field double-focussing high-resolution ICP-MS (installed in 2002 at PCIGR), is capable of analyzing many elements in solution at concentrations as low as parts per trillion (ppt) and has a dynamic range of over 9 orders of magnitude. Most interferences of elements caused by other elements in the sample matrix can be resolved by a careful selection of the resolution mode used, minimizing the need of extensive chemical separation steps.
At PCIGR, the Element 2 is employed weekly by multiple users, each of whom use a different application with a different sample matrix (seawater, fresh water, porewater, soil, rock, etc.). To date, users of the Element 2 have mainly employed the direct nebulization system using the spray chamber.
Applications of the Element 2 include trace element concentrations (REEs/HFSE or both) for mineral separates (e.g., apatites, fluorites, feldspars, clinopyroxenes); complete trace elemental profiles for a variety of lithologic materials (e.g., komatiites, basalts, granites, diorites, peridotites, anorthosites); and at least 13 different reference materials in rock matrices.
Other applications include trace element concentrations in seawater, plankton, peat, moss, street dust and storm water, an assessment of metal mobility in lake sediments contaminated with mine tailings, the characterization of As species in biological tissues and water samples, and studies in pharmacology. We also perform U-Pb geochronology of zircon and monazite, and trace element analysis of garnet, using an Elemental Science Lasers NWR193UC laser ablation system coupled to the Element 2.
The Element 2 is also extremely useful for our everyday lab quality control (lab blanks, reagent blanks, column calibration, exact sample contents for MC-ICP-MS analyses).
Fourny, A., Weis, D. and Scoates, J. 2016. Comprehensive Pb-Sr-Nd-Hf isotopic, trace element, and mineralogical characterization of mafic to ultramafic rock reference materials. Geochemistry, Geophysics, Geosystems, 17(3): 739-773, doi:10.1002/2015GC006181.
Smith, K., Weis, D., Amini, M., Shiel, A., Lai, V. and Gordon, K. 2019. Honey as a biomonitor for a changing world. Nature Sustainability, 2(3): 223-232, doi:10.1038/s41893-019-0243-0.
Li, M., Weis, D., Smith, K., Shiel, A., Smith, W., Hunt, B., Torchinsky, A. and Pakhomov, E. 2020. Assessing lead sources in fishes of the northeast Pacific Ocean. Anthropocene, 29: 100234, doi:10.1016/j.ancene.2019.100234.