PARENT SESSION
PS1 - Wildlife Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P021) Laser ablation ICP-MS: A unique analytical tool for trace element exposure assessment .
Jackson, Brian*,1, Hopkins, William1, Baionno, Jennifer1, 1 Savannah River Ecology Laboratory, Aiken, SC, USA
ABSTRACT- Ideal methodologies for continuous assessment of trace element exposure in wildlife should minimally impact the health of the sampled animals. Current approaches involve using blood, feather or skin samples followed by either dilution (blood) or acid digestion (feather, skin) prior to analysis. However, these techniques require dilution and or solubilization of the sample prior to analysis and, because of sample matrix effects, are prone to instrumental interferences. Additionally, tissue analysis requires a relatively large sample mass, which hinders continued regular monitoring of an individual through its lifetime. We investigated the use of laser ablation-ICP-MS (LA-ICP-MS) for the determination of trace element exposure in tail clips collected from snakes. Banded water snakes (Nerodia fasciata) were exposed to low, medium, or high concentrations of trace elements through their diet utilizing fish from a reference site, a coal ash-contaminated site, or a 1:1 mixture of the two. Pooled samples of shed skin and tail clips from each treatment were homogenized and finely ground using a cryogenic grinder and trace element concentrations determined by acid digestion and ICP-MS analysis. A sub-sample of each pooled shed skin and tail clip sample was pressed into a pellet for use as a solid calibration standard in LA-ICP-MS analysis. Solid tail clip samples were taken (ca. 2mm length, 1mg dry wt.) from individual snakes in each treatment (n=3). LA-ICP-MS calibration curves for As, Se and Sr were linear with R2 > 0.96. LA-ICP-MS of the tail clips showed increasing concentrations of As and Se with treatment consistent with increased dietary exposure to these elements and elemental concentrations determined by acid digestion ICP-MS.
Key words: Laser abaltion-ICP-MS, Trace element exposure assessment, arsenic, selenium