Courses using the XRF
UEI students performed an XRF soil screening study at APC Garden (Spring 2007).
Urban Environmental Issues (UEI)
Soil Screening experiments
Alameda and Oakland Field sites
The sampling in Alameda has occurred with permission from the Alameda Point Collaborative (APC). The APC garden and plant nursery have served as educational sites and the results are communicated back to the community partner. The sampling methodology has been the same as reported for the Oakland residential site.
The Oakland residential site screening experiment was written up as a formal lab experiment and published by the Journal of Chemical Education 2008, 85(7), 980-982.
Full size images of the US penny and dollar spectra are found on the following page, coinage spectra.
Demonstration of the instrument on metal samples including coinage
Coins with known elemental composition are useful. The US Mint reports the elementar composition and coins are readily available. .
US Pennies are probably the easiest to use. In 1982, the penny's composition was changed from an alloy (95 % Cu and 5 % Zn) to a copper plated zinc coin.
The adjacent image shows the pre-1982 coin in dark brown and the post-1982 coin in light brown. The peak intensities are quantitative for the pre-1982 coins. The peak intensities are not quantitative for the post-1982 which highlights the surface sensitivity of this instrumental methodology.
The two US dollars have distinctive XRF spectra. The Susan B. Anthony dollars are composed of two elements and the Sacagawea dollars are composed of four elements. Viewing the two spectra , one can quickly ascertain the elements that are the major components.
Students can be directed to use the Lawrence Berkeley Lab XRF periodic table to determine the elements in the two US dollar coins.
Environmental Chemistry students sampling soils near urban highway and quantifying lead content in soil. (Fall 2004).
Students gain skill with the instrument and general aspects of field sampling. The Gateway Highway 24 Interchange has been sampled in Spring 2003, Fall 2004, Fall 2006. XRF Field Sampling is shown in photo at top of page.
Alameda Point Collaborative Site Soil study
In Fall 2006, students applied their field sampling skills from the highway site characterization to double check on a site where a lead in soils removal action had occurred in Alameda.
Instrumental Analysis (contact Professor Shulman directly)