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Staff

Reston Stable Isotope Laboratory

Director: Tyler B. Coplen
    Lead Scientists:
    Tyler B. Coplen [Isotope Fractionation in Hydrologic Systems]
    J.K. Böhlke [Isotope Hydrology and Biogeochemistry]

    Location:
    Reston Stable Isotope Laboratory (RSIL)
    U.S. Geological Survey
    Mail Stop 431 -- Room 5B142
    12201 Sunrise Valley Drive
    Reston, VA 20192
    +1 (703) 648-5859

    Organizational Unit:
    National Research Program, Water Mission Area (Office of Hydrologic Research, Branch of Regional Research--Eastern Region https://water.usgs.gov/nrp/index.php )

RSIL Group Staff Picture
Group photo of the Reston Stable Isotope Laboratory (2009)

Jacqueline Benefield - Researcher I
Jacqueline Benefield Phone: 703-648-5827     E-Mail: jbenefield@usgs.gov
Jacqueline prepares and analyzes water and other samples for hydrogen, carbon, nitrogen, oxygen, and sulfur isotope ratio analysis. She also performs a wide range of tasks helping the laboratory to operate smoothly.

J.K. Böhlke - Research Hydrologist
J.K. Böhlke Phone: (703) 648-6325     E-Mail: jkbohlke@usgs.gov     Research website: http://profile.usgs.gov/jkbohlke
JK conducts research on methods and applications for isotopes and other environmental tracers in hydrogeology and biogeochemistry, including: field and laboratory studies of physical and biogeochemical processes affecting reactive inorganic constituents in ground water and surface water, with focus on redox sensitive compounds of oxygen, nitrogen, carbon, and sulfur; sources and fate of inorganic contaminants (e.g., nitrate, perchlorate); isotope analytical methods and calibrations.

Lauren Brandes - Chemist
Lauren Brandes Phone: (703) 648-5950     E-Mail: lbrandes@usgs.gov
Lauren prepares and analyzes water and other samples for hydrogen, carbon, nitrogen, oxygen, and sulfur isotope ratio analysis. She also performs a wide range of tasks helping the laboratory to operate smoothly.

Bryan Buck - Engineering Technician
Bryan Buck Phone: (703) 648-5874     E-Mail: bbuck@usgs.gov
Bryan provides indispensable mechanical support and development, as well as preparing and analyzing samples for isotopic composition.

Tyler B. Coplen - Research Chemist
Tyler B. Coplen Phone: (703) 648-5862     E-Mail: tbcoplen@usgs.gov     Research website: https://profile.usgs.gov/tbcoplen
Tyler uses variations in the isotopic abundances of hydrogen, carbon, nitrogen, oxygen, and sulfur to investigate problems in hydrology, geochemistry, and paleoclimatology, oversees the analysis of samples submitted by USGS and other entities for isotopic analysis, and develops new sample preparation and mass spectrometric data acquisition and control techniques for analysis of the isotopes of light elements.

Janet Hannon - Chemist
Janet Hannon Phone: (703) 648-5202     E-Mail: jehannon@usgs.gov
Janet analyzes water samples and solids for nitrogen-15 of nitrate, ammonium, and organic nitrogen. She also develops methods for separating solutes such as ammonium, nitrite, nitrate, chloride, and sulfate for isotopic analysis.

James Jordan - Visiting Scientist
James Jordan Phone: (703) 648-5836     E-Mail: jajordan@usgs.gov
James is highly experienced in analytical chemistry and is interested in development of new methods of hydrogen, carbon, nitrogen, oxygen, and sulfur isotope ratio determinations in organic materials.

Jennifer Lorenz - Biologist
Jennifer Lorenz Phone: (703) 648-5894     E-Mail: jlorenz@usgs.gov
Jennifer prepares and analyzes water and other samples for hydrogen, carbon, nitrogen, oxygen, and sulfur isotope ratio analysis. She also works on the RSIL web site and handles the RSIL reference materials and calibration orders.

Stanley Mroczkowski - Chemist
Stanley Mroczkowski Phone: (703) 648-5870     E-Mail: smroczko@usgs.gov
Stan performs isotopic analyses of dissolved gases and other solutes including sulfate and perchlorate. He also performs experiments to improve isotopic analysis for applications in biogeochemistry.

Haiping Qi - Chemist
Haiping Qi Phone: (703) 648-6338     E-Mail: haipingq@usgs.gov
Haiping is experienced in solid-source mass spectrometry (e.g., Li, B, and Cl isotopes) and gas source mass spectrometry techniques as well. She is involved in preparation of new isotopic reference materials, and assists in laboratory management and daily operation of the laboratory, analyzing samples submitted for hydrogen, carbon, nitrogen, oxygen, and sulfur isotope ratio determination.

Kinga M. Revesz - Research Chemist (Emeritus)
Kinga M. Revesz Phone: (703) 648-5865     E-Mail: krevesz@usgs.gov
Kinga is concerned broadly with the use of stable isotopes, primarily hydrogen, carbon and oxygen, to examine the dynamics of hydrological systems and associated geochemical problems. Performs studies in the identification and quantification of ground-water recharge, discharge, and surface-water/ground-water interaction, as well as redox processes in contaminated aquifers. Develops new sample preparation techniques in the laboratory including inlet systems for continuous flow isotope ratio analytical techniques , such as EA, TC/EA, GPI, Gasbench, GCC, TC/GCC and TIC/TOC.

Lauren Tarbox - Physical Scientist (Volunteer)
Lauren Tarbox E-Mail: ltarbox@usgs.gov
Lauren is now a volunteer working on RSIL special projects.

April Thorne - Project Assistant
April Thorne Phone: (703) 648-5856     E-Mail: athorne@usgs.gov
April provides administrative support to the entire RSIL staff.