The Micro-Analytical Geochemistry Lab at the GSO is operated by Prof. Katherine Kelley as a fee-for-service URI Service Center, which provides sample preparation and analytical services largely focused on analysis of microscopic solid materials.

• Solution-based ICP-MS: The geochemistry laboratory at the Graduate School of Oceanography (GSO), University of Rhode Island houses a Thermo Electron X-series 2 Quadrupole ICP-MS equipped with a SIM electron multiplier that operates in pulse counting and analog modes, and has interchangeable Xs and Xt interfaces. It has Plasma Screen and Collision Cell Technology options that allow for optimizing the signal/background ratio and reducing polyatomic interferences. Sample introduction methods for dissolved rock samples include a fully automated ESI auto-sampling system, a peristaltic pump and Peltier cooled spray chamber with a concentric nebulizer, and a desolvating nebulizer and a hydride generator for specialized sample introduction. The sensitivity of the Thermo instrument allows for single figure ppt to ppq detection in solution mode across the mass range, including Li, Be, and U and up to 10 ppm of major elements. This lab performs routine analyses of 38 minor and trace elements. (Li, Be, Sc, Ti, V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Cs, Ba, Ba, REE, Hf, Ta, Pb, Th, U) and protocols may be optimized for several others (e.g., K, As, Sb). Since the summer of 2005, the GSO laboratory has been routinely used for analyses of igneous rocks. Typical sensitivities for a 1 ppb solution are 60,000 cps @ 7Li to 400,000 cps @ 238U. Analyses of volcanic rocks have average reproducibility of <2% RSD across the mass range.
• Laser ablation ICP-MS: The ICP-MS lab is equipped with an Elemental Scientific NWR193 laser that is connected to the Thermo Electron X-series 2 ICP-MS. Detection limits in this analysis mode for glasses are typically in low ppm to ppb range depending on ablation and instrument conditions. Typical uncertainties are ≤5% relative. The lab performs routine laser ablation analyses of >40 major, minor, and trace elements (Li, Be, Mg, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr, Y, Zr, Nb, Cs, Ba, Ba, REE, Hf, Ta, W, Pb, Th, U) in situ using spots as small as 20 μm. The following glass standards are available for LA ICP-MS calibration: USGS basaltic reference glasses (BHVO-2G, BCR-2G, BIR-1G); MPI-DING glasses (ATHO-G rhyolite, T1-G quartz diorite, StHS6/80-G andesite, KL2-G basalt, ML3B-G basalt, GOR128-G komatiite and GOR132-G komatiite); NIST synthetic glasses (NIST 610, 612, 614, and 616).
• Micro-FTIR Spectroscopy: The Microanalytical Geochemistry Lab houses a Thermo Nicolet iS50 Fourier transform infrared spectrometer with Continuum microscope interface, for micro-analysis of dissolved volatiles (H2O, CO2, OH-, CO32-) in glasses, but can also detect many other bonding environments associated with IR-active C-O-H bonds in organic and inorganic materials, using both transmission and reflectance modes. The system is equipped with a fully automated sample stage for fine-scale sample mapping and automated point-to-point analysis. The system includes a self-contained purge gas generator for purging the sample area with dry, CO2-free air. The Continuum microscope has a 15x IR reflachromat objective and condenser, and 250 μm and 50μm MCT-A detectors for high-resolution data collection at small spot sizes over a broad spectral range. The system also includes sample chambers for analysis of larger media and powdered materials.
• Scanning Electron Microscopy: The lab houses a Thermo Phenom XL G2 bench-top scanning electron microscope, equipped with secondary electron and backscattered electron imaging modes, and an energy dispersive spectroscopy (EDS) detector for coarse elemental microanalysis of glasses and minerals, which can be used for both spot analyses and dimensional mapping. This system can be easily employed to screen samples for general major element characteristics prior to more laborious sample preparation or quantitative geochemical analysis.
• Clean Chemistry Laboratories: Chemical preparations of bulk rock samples are performed at the associated clean chemistry lab facility under the direction of Dr. Katherine Kelley. The clean laboratory includes an 18.2 MΩ Milli-Q water polisher, a class 100 polypropylene laminar flow fume hood, and two Savillex DST-1000 teflon stills, and two quartz stills for the in-house production of triple-distilled acids used throughout sample preparation. High-precision balances and Teflon digestion vials are used to weigh out and dissolve sample powders using HF-HNO3 acid attack at low temperatures (≤100°C). The lab is also equipped with a broad range of international and in-house igneous and sedimentary rock standards spanning the compositional range of basalt to rhyolite, including those from USGS and GSJ. The facility also houses a Perkin Elmer MultiWave 3000 microwave system for digestion of highly refractory minerals (e.g., zircon, spinel) that may not dissolve in a standard hot plate digestion.