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Overview

Why is USGS doing this project?

The USGS Mineral Resources Program and other USGS scientists need specialized routine analysis in order to carry out their research.

geochemical samples
USGS National Geochemical Sample Archive in Denver, Colorado. Photograph by USGS.

What is this project going to do?

The Central Mineral and Environmental Resources Science Center's Analytical Chemistry Project combines and coordinates the chemistry functions that are necessary for research and assessment projects to obtain these analyses. Our project is responsible for:

  • the physical preparation and tracking of the samples through in-house and contract laboratories via a Laboratory Information Management System;
  • routinely analyzing samples using methods such as instrumental neutron activation analysis, wavelength dispersive x-ray fluorescence, atomic absorption spectroscopy, coulometric titration and combustion;
  • validating both in-house and contract analytical techniques, monitoring contract chemistry data quality and validating contract chemistry analytical results;
  • disseminating analytical results to staff scientists; administering the Laboratory Information Management System; which is fully integrated with in-house laboratories and Sample Control;
  • and maintaining and growing the National Geochemical Sample Archive.

Recurring efforts include:

  • maintaining equipment and methods of analysis for in-house analytical chemistry work;
  • offering a mechanism to prepare samples;
  • contracting routine chemical requests to an outside laboratory; and providing data quality control for both in-house and contract generated data.

Long term efforts include: continued support to the Mineral Resources Program and other USGS scientists by providing these services and the modification of analytical methods and/or administrative procedures to better meet the needs of the scientists.

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Sample and Data Management

Contacts: Jaime Azain, jsazain@usgs.gov, and David Fey, dfey@usgs.gov

We perform all the necessary functions relating to the receipt, preparation, shipment, data tracking, quality control, and archiving of samples for chemical analyses. These functions are performed for both in-house and contract laboratory analyses.

Specific task objectives are as follows:

  • Maintain the Laboratory Information Management System (LIMS) to track workflow through contract and in-house analytical laboratories and present final data in a format consistent for use in other databases.
  • Contract out routine analytical chemistry functions to an outside laboratory that is cost effective at the required quality limits.
  • Perform quality assurance and quality control (QA/QC) function for all chemical analyses and maintain database for both contract and in-house chemistry that is adequate for Environmental Protection Agency, Water mission area, and Chain-of-Custody protocols.
  • Perform physical preparation of samples by crushing, grinding, sieving, etc. for chemical analysis prior to submission to contract and/or in-house laboratories.
  • Operate and maintain the USGS National Geochemical Sample Archive, inventory, and retrieval of previously analyzed powdered geochemical materials.

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Instrumental Neutron Activation Analysis (INAA) and Delayed Neutron Activation Analysis (DNAA)

Contact: James Budahn, jbudahn@usgs.gov

We provide routine instrumental neutron activation analysis (INAA) and delayed neutron activation analysis (DNAA) for the determination of a wide range of major, minor, and trace element concentrations for USGS science projects. Concentrations of other elements can be determined if requested, development of methodology may be required. The methods offer low limits of detection and high accuracy and precision for many elements in geologic, environmental, and biologic samples. The analyses are carried out using pulverized solid samples, so chemical disolution of the sample is not required. This technique provides highly accurate chemical determinations on solid geologic materials without the need for any chemical pretreatment of the sample split and is ideally suited to the precise determination of rare earth elements in geologic samples.

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X-Ray Fluorescence Major, Minor, and Trace Element Chemistry

Contact: James Budahn, jbudahn@usgs.gov

We provide high precision determinations of 10 major rock-forming elements as oxides and the determination of minor and trace elements in solid geologic materials using wavelength dispersive x-ray fluorescence (WDXRF). The accuracy achievable using the wavelength dispersive x-ray fluorescence technique for the determination of major elements as oxides is unsurpassed by any other instrumental technique. The error of determination is typically 0.5% relative error or less for major elements at crustal abundance levels. The percent relative standard deviation for trace and minor element determinations by wavelength dispersive x-ray fluorescence is typically between 5% and 10% for elements free of overlaps and concentrations of > 100 ppm. Samples are prepared at the our laboratory facility and analyzed using a Rigaku ZSX Primus II X-ray fluorescence instrument.

Techniques

The major element technique uses a lithium tetraborate fusion disk sample for presentation into a wavelength dispersive X-ray fluorescence spectrometer. The method is well-proven for analyzing all types of rocks, soils, and most types of minerals. The results are important in identification and chemical classification of geologic materials, as well as following temporal amd mass balance chages in geologic environments.

The minor and trace technique uses a homogeneous powdered sample which is placed in a 20 mm cuvette with an attached prolene film to prevent sample spilling. The cuvette is introduced into the spectrometer for analysis. Rocks, stream-sediments, and soils are typically analyzed to provide mineral and trace element data for petrologic, economic, and environmental studies.

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In-House Chemistry Support Services

Contact: Cyrus Berry, cjberry@usgs.gov

We provide highly accurate and precise research-related single element analyses which include:

  • total carbon,
  • carbonate carbon,
  • organic carbon,
  • dissolved organic carbon,
  • total sulfur,
  • mercury,
  • arsenic, and
  • selenium.

In addition to housing the single element analytical capability we also provide common laboratory support services such as the purchase of liquefied and compressed gases, the maintenance and repair of laboratory instrumentation, and the purchase of laboratory supplies such as acids, solvents, glassware, etc.

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Contract Chemistry

Contact Jaime Azain, jsazain@usgs.gov

We send over half of the submitted samples to an external contract laboratory for analysis. The contract laboratory analyzes USGS samples using a variety of 24 multi and single element analytical techniques. All of the techniques used by the contract laboratory are either identical and/or similar to established USGS methods. This effort leads to better analytical control and data consistency over time. In addition, the contract laboratory and the data it generates are monitored closely to ensure data quality meets established USGS criteria. We add quality control samples to all jobs submitted for contract chemistry. The analytical results are uploaded into our Laboratory Information Management System and delivered to the sample submitter in digital format.

We monitor the contract laboratory to ensure that all aspects of the contract are executed within the limits established in the statement of work and all performance criteria are met. We facilitate communication between the USGS and the contract laboratory to confer any issues or questions that arise. The intent of these discussions is to enhance data quality and improve laboratory efficiency.

We evaluate new analytical techniques for potential inclusion in the contract based on the needs of USGS Mineral Resources Program research and assessment projects.

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Products

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Inmachuk, Kugruk, Kiwalik, and Koyuk River drainages, Granite Mountain, and the northern Darby Mountains, Bendeleben, Candle, Kotzebue, and Solomon quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-4, 5 p., doi:10.14509/29448.

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Haines area, Juneau and Skagway quadrangles, southeast Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-5, 5 p., doi:10.14509/29449.

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Kougarok area, Bendeleben and Teller quadrangles, Seward Peninsula, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-6, 5 p., doi:10.14509/29450.

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the northeastern Alaska Range, Healy, Mount Hayes, Nabesna, and Tanacross quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-7, 6 p., doi:10.14509/29451.

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Tonsina area, Valdez Quadrangle, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-8, 5 p., doi:10.14509/29452.

Werdon, M.B., Granitto, Matthew, and Azain, J.S., 2015, Geochemical reanalysis of historical U.S. Geological Survey sediment samples from the Zane Hills, Hughes and Shungnak quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2015-9, 5 p., doi:10.14509/29453.

Werdon, M.B., Azain, J.S., and Granitto, Matthew, 2014, Reanalysis of historical U.S. Geological Survey sediment samples for geochemical data from the western part of the Wrangellia terrane, Anchorage, Gulkana, Healy, Mt. Hayes, Nabesna, and Talkeetna Mountains quadrangles, Alaska: Alaska Division of Geological and Geophysical Surveys Raw Data File 2014-5, 6 p., doi:10.14509/27287.

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Project Contact

Jaime Azain
Phone: 303-236-9376
Email: jsazain@usgs.gov
Central Mineral and Environmental Resources Science Center

Mineral Resources Program Science Priority

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