Isotope Geochemistry

Constructed in 2016, The Center for Isotope Geochemistry at Boston College is a world-class facility for the high-precision isotope analysis of a wide array of materials.  Located within the Earth and Environmental Sciences Dept. in Devlin Hall, the Center currently consists of a 750 sq ft class 1000 trace-metal clean room with class 100 work spaces, an Isotopx Phoenix Thermal Ionization Mass Spectrometer (TIMS), a Thermo Delta V Isotope Ratio Mass Spectrometer (IRMS) equipped with a Gas Bench II, and a mineral preparation laboratory including a New Wave MicroMill. The Center specializes in small-sample Sm, Nd, and Sr isotope analysis on a variety of earth materials, in addition to paleoclimate research using N, C, O, and H isotope measurements of carbonates and marine and environmental samples.

Principally, the Center takes a collaborative approach to research and in most circumstances the users are trained how to prepare, separate, purify, and analyze samples under the direction of Center management.  We value the educational experience of all users and highly encourage motivated undergraduates to get involved in the research activities of the Center. Interested parties and external users should contact Center management to discuss details of prospective collaboration.

Facility Director: Steph Walker
Faculty Advisory Committee:
Chair of FAC and Lead contact for TIMS: Ethan Baxter
FAC Member and Lead contact for IRMS: Xingchen (Tony) Wang
FAC Member and Lead contact for the SEM: Seth Kruckenberg

New Clean Room

Center Facility Description

Two trace-metal clean rooms comprising ~750 sq ft are the heart of the Center. The metal-free HEPA filtered labs are designed for the processing of small amounts of sample (sub nanogram) with minimal environmental contamination. The space features 14 Class 100 ULPA filtered laminar flow benches and hoods, Savillex Teflon distillation devices, Analab metal-free hotplates, and three analytical balances. The labs are designed to hold a steady temperature and positive pressure is monitored via a Setra Multisense monitor at the interface of each lab door.

Isotopx Phoenix Thermal Ionization Mass Spectrometer (TIMS):

Isotopx Phoenix Thermal Ionization Mass Spectrometer (TIMS): Installed in 2016, the instrument is equipped with nine movable Faraday detectors and an ion counting Daly detector. The sensitivity of the TIMS permits acquisition of high-precision (10 ppm) isotope data for the smallest samples down to the sub-nanogram level for high mass elements (e.g. 143Nd/144Nd, 87Sr/86Sr). All filaments are prepared in-house using an Amada Miyachi spot welder and degassed in a DG60 outgasser device. Samples are loaded under ULPA-filtered laminar flow conditions using an in-house designed filament loading bench.

Thermo Delta V Plus Isotope Ratio Mass Spectrometer (IRMS)

Thermo Delta V Plus Isotope Ratio Mass Spectrometer (IRMS): Upgraded in 2016, a; the IRMS is equipped with universal triple collectors and D/H collectors for a variety of stable isotope measurements. The IRMS is linked to a Conflo IV for sample dilution and a GasBench II equipped with a 96 port heating block and autosampler for preparation and sample introduction of carbonates, water samples, and atmospheric gasses. The setup allows for high-throughput automated continuous flow isotope analyses of CO2, O2, N2, and H2 gasses, respectively. Multiple fine-scale drilling devices and a Sartorius microgram level analytical balance are available for the drilling and weighing of sample powders.

Mineral preparation laboratory: An associated facility for the processing of solid samples and isolation of specific mineral phases. The lab features a Spex ball mill for producing powders from rock fragments, petrographic and binocular microscopes, an exhausting hood used for heavy liquid density separation, a new Frantz isodynamic separator for magnetic separation, and a New Wave MicroMill device for high precision sampling.

Please note that all work performed in BC core facilities and recharge centers should always be appropriately acknowledged.  If you are publishing or presenting data acquired in BC core facilities and recharge centers, please include the following statement in the Acknowledgement section of your manuscript/poster/presentation, "The authors would like to thank the Boston College <insert facility name> for assistance with the work presented in this paper/poster/presentation*."
* Delete as appropriate

Stephanie Walker

Stephanie Walker, Ph.D.
Director, Center for Isotope Geochemistry

Dr. Stephanie Walker is an isotope geochemist specializing in geochronology of the solid Earth. She joined BC in 2017 as a postdoctoral fellow in the Department of Earth and Environmental Sciences after completing her PhD at Royal Holloway University of London. Steph has extensive expertise in the extraction and isolation of elements (particularly Sm, Nd, Lu, Hf, Rb, Sr) using clean-lab chemistry and column chromatography, and analysis of their isotopes using TIMS and MC-ICPMS. She also has experience of determining trace- and major-element concentrations using LA-ICPMS and XRF. Her research focuses on using isotope geochemistry and geochronology to understand the timing and rates of metamorphic processes, particularly in orogenic systems.

Center for Isotope Geochemistry
Stephanie Walker, Ph.D.
617 407-5208
Devlin Hall 211