The mission of the Geochemistry Laboratories (GL) of the Department of Geology is to produce the highest quality elemental and isotopic data, to teach students and visitors the techniques involved in gathering and analyzing such data, and to develop new mass spectrometric methods and instrumentation.

The main areas of research of the GL include studies of the Earth’s core, mantle, crust, hydrosphere and atmosphere. We also contribute to the understanding of the chemical evolution of the Solar System via studies of lunar, Martian and asteroidal materials.

PEOPLE

The faculty/staff currently engaged in research in the GL include:

Ricard Arevalo, Richard Ash, Katherine Bermingham, Shuiwang Duan, Michael Evans, James Farquhar, Jay Kaufman, Sujay Kaushal, Bill McDonough, Sarah Penniston-Dorland, Igor Puchtel, Richard Walker, and Nanping Wu.

FACILITIES

There are five separate mass spectrometry facilities (Thermal Ionization, Gas Source I, Gas Source II, M-CLASS and Plasma), as well as an analytical biogeochemical facility within the Geochemistry Laboratories. The facilities also include laboratories for the chemical processing of geologic and hydrologic samples (8), mineral separation (2) and rock preparation. These labs are located on the first and ground floors of wing two of the Chemistry Building, the ground floor of the Toll Building, and on the first floor of the Biochemistry Building. In addition, a new Gas Source facility is currently being constructed in the Atlantic Building.

Thermal Ionization Mass Spectrometry Laboratory: This laboratory (CHEM 0218) contains two Thermo-Fisher Triton thermal ionization mass spectrometers. These mass spectrometers use hot metal filaments to ionize highly-purified elements extracted from mineralogical matrices. The ions are then introduced into the magnetic sector of the mass spectrometers for high precision isotopic measurement.

Two adjoining 500 sq. ft. clean laboratories (CHEM 0216a and 0216b) are supplied with HEPA filtered air, contain a total of five class-100 vented laminar flow hoods, two chemical fume hoods, one water washed hood for use of perchloric acid, twenty individual work stations (with fume extraction), two Milli-Q water purification systems, a Mettler AE240 balance and various sub-boiling stills (quartz and teflon), including two Savillex teflon stills.

Plasma Laboratory: This laboratory (CHEM 0225) is dedicated to elemental and isotopic studies using inductively-coupled plasma mass spectrometry (ICP-MS) that employs a high temperature plasma as an ion source. This laboratory houses a Thermo Neptune Plus multi-collector ICP-MS and a Thermo Scientific, Element 2, single-collector ICP-MS. Also installed is a New Wave Research UP 213 laser ablation system, three high-temperature desolvating nebulizer systems (Aridus II, Aridus III and Apex) and two low-temperature, glass spray chambers (Scott-double pass and cyclonic). The UP 213 ultraviolet laser ablation system uses a Nd:YAG crystal and three harmonic generators to deliver 213 nm light to produce a spot (5 to 250 micron diameter). This can be used to analyse indivual spots or rastered for line traces. These various sample introduction systems allow for the analyses of either solid or liquid samples.

A 250 sq. ft. laboratory (CHEM 0227) adjacent to the ICP-MS laboratory is used for sample preparation for ICP-MS analyses. It contains a recirculating fume hood, a Milli-Q water purification system and a Mettler AT21 micogram electronic balance. An adjacent 150 sq. ft. laboratory (CHEM 0227A) contains optical microscopes and sample characterization equipment and 3 data processing computer stations.

Gas Source Mass Spectrometry Laboratory I: This laboratory (CHEM 0233) houses a Finnigan MAT 253, dedicated to high precision analysis of rare isotopes of sulfur (³³S and ³⁶S) for atmospheric, environmental, geochemical, and cosmochemical applications. This laboratory also houses an Agilent HPLC and a Dionex HPIC for concentration determination and preparative work of sulfur species, and a workstation for computations using the Gaussian software package.

A 500 sq. ft. chemical preparation laboratory (CHEM 0230) is used for chemical extraction and preparation of sulfur and oxygen samples by a variety of techniques. This laboratory is dedicated to chemical preparation of samples for atmospheric, environmental, geochemical, and cosmochemical research. It includes a variety of gas extraction manifolds, gas chromatography, fluorination manifolds, and wet chemical facilities.

A 250 sq. ft. laboratory (CHEM 0231) adjacent to GS I houses UV lamps for photochemical experiments, two experimental constant temperature baths, and autoclave, and a chamber for handling of samples under anoxic atmospheres.

Gas source Mass Spectrometry Laboratory II: CHEM 1216 houses four Elementar Isoprime mass analyzers and associated sample preparation peripherals. One of these is dedicated to dual inlet (DI) measurements, particularly for the automated analysis of the isotopic composition of carbonate (C, O) and water (O, H) samples to high analytical accuracy and precision. The second utilizes continuous flow (CF) inlet systems coupled with Eurovector elemental analyzer (EA) combustion ovens for the automated isotopic analysis of organic matter (C, N, S), as well as mineral sulfates (S), sulfides (S), and nitrates (N). The third Isoprime is coupled to a Costech Analytical high temperature generator and elemental combustion system, and is dedicated to CF analysis of C and O in solid organics. Isoprime four is coupled to a customized high-throughput Elementar Multiflow carbonate and water autosampler, and is dedicated to CF analysis of carbon and oxygen in carbonates and waters. A Sartorius C2P microbalance in a dedicated alcove provides 2µg repeatability on mass measurements.

A separate 500 sq. ft. chemical preparation laboratory (CHEM 0224) is dedicated to the isolation of carbonate and organic matter from geological samples for elemental and stable isotope analysis in GSMSII. In particular, this laboratory is dedicated to the preparation of stratigraphic suites of marine carbonates and organic-rich siliciclastics for chemostratigraphic research. This facility includes: Struers Labopol-21 two-wheel grinding apparatus; ServoProducts 7170 drill press; Thermolyne FA 1635 combustion oven; VWR utility drying oven; Mettler AB 104 balance; Fisher Scientific centrifuge; and two six foot Kewaunee fume hoods for acid and solvent extractions.

A 200 sq ft. laboratory (CHEM 1214) adjacent to GSMSII is used for sample preparation for carbonate and cellulose samples. It contains two fume hoods with cup sinks, plumbed house deionized water, vacuum, gas and compressed air, a rotary microtome, 2 high speed microcentrifuges, drying oven and other equipment for disaggregation and sampling of various paleoclimatic archives.

M-CLASS (Measurement of Composition via Laser Ablation Sampling and Spectrometry) Laboratory. The joint UMD/NASA M-CLASS Laboratory focuses on the comprehensive chemical analysis of terrestrial materials and planetary analogs by state-of-the-art commercial instrumentation as well as technologically advanced hardware miniaturized and ruggedized for spaceflight applications and the in situ exploration of planetary surfaces. This lab houses both commercial (Nu Instruments AttoM) and prototype ICPMS instruments, and multiple Orbitrap mass analyzers (including a MALDI LTQ Orbitrap XL), all of which may be interfaced to a variety of laser systems, such as a New Wave FemtoUC (femtosecond ablation) or Photon Machines Analyte G2 excimer laser, or brassboard laser systems currently under development for deployment on future planetary lander/rover platforms. The lab also offers a chemical fume hood for sample processing, optical table for active vibration isolation and instrument testing, and multiple electrostatic dissipative (ESD) benches for electronics development.

The Paleoclimate CoLaboratory (CHEM 1212) is adjacent to GSMSII, and contains a 48 core, 64Gb shared memory, networked compute server for statistical data analysis and molecular energy simulations. The server also manages data backup for and network connections into GSMSII computers, and operates as a thin client server. CHEM 1212 also includes a multipurpose room with digital projector and whiteboards for collaborative project development and informal seminars.

Mineral Separation and Rock Preparation Laboratories: These labs (CHEM 0212, 0219 and 0234) include conventional jaw crusher and disk mill, tool steel and alloy mortar and pestles, SPEX Industries Shatterbox with agate and alumina grinding chambers, Leco diamond slow-speed saw for cutting iron meteorites, Wilfley table, high density liquids (methylene iodide, bromoform and Na polytungstate), a Frantz Co. magnetic barrier separator, a Buehler automated polisher, and a stereo microscope for hand-picking separates.

Microscope Laboratory: The Microscope Laboratory has a Nikon LV100POL petrographic microscope connected to a Dell PC along with QCapturePro software for photographic documentation of samples. There is also a Meiji EMZ-5TR binocular zoom stereo microscope for mineral separation.

Biogeochemistry Laboratory: The biogeochemistry laboratory is comprised of two adjoining 500 sq. ft. laboratories in the Biochemistry Building (BIOCHEM 1511 and 1513). The lab contains a Milli-Q water purification system and also is equipped with compressed air, vacuum, and gas lines. There are fume hoods for work with acids and organic solvents. It contains a Shimadzu ICP-OES for elemental analyses. It contains a Dionex ion chromatograph for analysis of anions in water such as nitrate (N), sulfate (S), chloride (Cl), fluoride (F), and bromide (Br). It contains a Lachat autoanalyzer for analysis of all major inorganic and organic fractions of nitrogen (N) and phosphorus (P) and silica (Si). A Shimadzu TOC/TN analyzer is used for analysis of dissolved inorganic and organic carbon (C) and total dissolved nitrogen (N). There is a Horiba Jobin Yvon spectrofluorometer for spectroscopic characterization of dissolved organic matter and optical tracers. There are centrifuges, incubators, autoclaves, gas manifolds, vacuum pumps, sieves, and freezers for preparation, storage, and archiving of water and sediment samples. In addition, there is field equipment for routine and isotope and hydrologic tracer studies in watersheds such as peristaltic pumps and handheld meters and continuous sensors for measurements of streamflow, temperature, conductivity, pH, and dissolved oxygen.

Last Modified August 2018