ELEMENTAL ANALYSIS

The Earth & Planetary Sciences Department at UC Santa Cruz maintains a complete set of tools with which to measure elemental composition. X-ray fluorescence (XRF) is used to measure major, minor, and some trace elements in bulk solids, and electron probe micro analysis (EPMA) is used for spatially-resolved analyses of these elements. Trace and ultra-trace concentration measurements in both solids and liquids are performed inductively-coupled mass spectrometry (ICPMS), both quadrupole-based and high-resolution magnetic sector instruments. Additionally, through the Institute of Marine Sciences lab in our building, we have access to inductively-coupled optical emission spectroscopy (ICPOES), atomic absorption spectrophotometry, ion chromatography, gas chromatography, and gas chromatograph mass spectrometry.

INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY

In the spring of 2009 a new plasma analytical facility was established to replace our 15 year old Element 1 (the first of its kind in and academic lab in the U.S.). The new facility includes a Thermo Element XR (extended range) magnetic sector high-resolution ICPMS, an X-series quadrupole ICPMS, a Photon Machines Analyte 193H excimer laser system and Zygo NewView 7200 Vertical Scanning Interferometer (for inspecting laser ablation pits). Combined with our complete suite of plasma introduction systems (desolvating nebulizers, flow injection system, Peltier-cooled spray chambers, etc.), we are equipped to measure most of the periodic table, over a wide range of concentrations, in solids and liquids of a wide range of compositions. A diverse user group includes marine chemists, igneous geochemists, archaeologists, inorganic chemists, geochronologists, environmental toxicologists, and paleo-oceanographers, to name a few.

Element XR

X-series ICPMS and Photon Machines laser

X-RAY FLUORESCENCE ANALYSIS

In the winter of 2006 we replaced our aging Philips AXS (one of the very first automated X-ray fluorescence spectrometers) with a very lightly-used, state-of-the-art XRF, donated by Quadra Mining. Used for only six months in 1998 at the Robinson Mine, Ely, NV, and mothballed for the next seven years, this Philips (now PANalytical) PW2404 comes equipped with a 4KW generator, a sharp-focus end-window Rh tube, an automated 96-sample changer, and a full complement of tube filters, analyzing crystals and detectors. This system utilizes all of the modern methods for spectrometric analysis and data reduction, and is capable of measuring a wide variety of materials, both solid and liquid, for major and trace element concentrations, qualitatively, semi-quantitatively, and quantitatively. Earth & Planetary Sciences at UCSC has been performing XRF analyses of the highest quality for 40 years, and with this new facility we are equipped to continue to do so for many years to come.

ELECTRON PROBE MICROANALYSIS

Our ARL-SEMQ electron probe microanalyzer, was acquired in 1992 and upgraded to run on the Advanced Microbeam interface and Probe for Windows software. The system has 9 wavelength-dispersive spectrometers, six fixed and three scanning, which allows for very rapid major and minor element analysis of common silicate minerals (as fast as ten seconds per spot). The unit is also fitted with EDS, as well as secondary, backscattered and cathode-luminescence imaging. The software allows for X-ray mapping based on the output of the wavelength-dispersive detectors, and allows for fully automated analysis using mapped digital shapes, transects, and points. Quality of the elemental analysis data is very high due to rapid analysis time and excellent filament stability.

dsampson@pmc.ucsc.edu