XRF Research

This page will be updated as the research progresses.

Soil Screening

Quantifying Lead

Environmental Chemistry students sampling soils near urban highway and quantifying lead content in soil. (Fall 2004).Lead content in soil samples is under investigation.  The soil samples are collected in residential area where the age of the housing stock is likely to have lead based paint.  These studies are done as in class labs. 

A 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.

One chemistry major has performed an independent research project on soil samples provided from Alameda County  validating the student's ablitiy following EPA Method 6200.

Students in the Environmental Chemistry lab gain skill with the instrument and general aspects of field sampling.  The Gateway Highway 24 Interchange site has been sampled in Spring 2003, Fall 2004, Fall 2006. 

Student records background measurements at field site adjacent to Highway 24 (Fall 2004).XRF Field Sampling is shown in top photo to the right.

This field site is changing as Cal-Trans upgrades Highway 24.  The dynamic changes are investigated in the lab.

The collection of soil core is underway at the present time and the experimental results will hopefully yield some useful trends.

Quantifying Lead in Condor Feces

This research began following a question whether the XRF methods could be employed to determine when a condor had ingested some lead.  The analysis of the feces would provide a less invasive method than the current blood lead sampling.  To determine some limits of the instrumentation, clean turkey vulture feces were obtained and small quantities of lead were added to the feces to address the instrumental detection limits without harming any wildlife.  This preliminary work was done as research collaborations were established with organizations that monitor and care for the wild condor populations.  This feces sampling has other difficulties in that condors stay in a flock, so individual samples are easily obtained. 

Three different condor feces samples have been obtained over the past few years.  Two zoos have provided samples from their condors which represent clean blanks.  Some wild condor feces have been provided by two organizations managing the two California flocks.  These samples are aggregated condor samples since the samples are obtained from the flight pens when birds are captured to have their blood analyzed.  Finally samples from two condors that have undergone lead remediation therapy yielded other samples where the lead would obviously be present and analysis can confirm that the therapy is indeed effective.

Quantifying Arsenic

An opportunity to study arsenic in soils is being developed.  If samples don't contain lead as an analyte, then the quantification of arsenic should be straightforward.  A few field investigations are being planned.

Other Mediums

Dust Wipe Analysis

Some preliminary samples were collected in a residence and supported the soil study where lead from old paint was identified.  The dust wipe samples may be sent to colleagues as a sample to further validate our use of dust wipes in the curriculum.  To use dust wipes, a confirmatory method of analysis is critical and a  partnering institution will be necessary.