USING INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY TO ANALYZE THE ELEMENTAL COMPOSITION OF DIDYMOSPHENIA GEMINATE

The single celled freshwater algal diatom, Didymosphenia geminata (didymo) is an invasive algal species that produces large and repugnant stalk mats or ‘blooms’ in streams. Didymo was first observed in the Faroe islands (Scotland) in the early 19th century, it has been spread worldwide and identified in four rivers of Virginia. Basic biological and chemical data are being collected to provide a better understanding of this pest with the hope that future mitigative measures may be developed. The goal of our project was to determine an “elemental fingerprint” for didymo collected from the Jackson River in Bath County, Virginia. A two step process of base and acid digestion to dissolve silica (SiO2) and organic matter, respectively, with microwave assisted digestion was successful in preparing aqueous solutions that were subsequently analyzed by Inductively Coupled Plasma – Mass Spectrometry (ICP-MS). Water chemistry was also determined for the reach of the river where Didymo was found. Twenty nine elements in the didymo and water samples were evaluated for this project. It was found that Cd, Sb, Bi, Tl, In, and Ag were below ICP-MS detection limits. Elements that were detected by ICP-MS in the didymo with high concentration (>1000 ppb) were Mg, Al, K, Ca, Mn, Fe and Ni. Elements that were found in moderate concentration (>10 ppm) were Li, B, P, Cr, Co, Zn, Ga, Sr, Ba, and Pb. Trace element analysis of the stream water was also conducted with Mg, P, K and Ca found at high levels. A statistical interpretation of the data will be presented in this poster.

Additional Abstract Information

Student(s): Phillip C. Chambers, Waleed Ahmad, Joline McNece

Department: Chemistry and Biochemistry

Faculty Advisor: Dr. Daniel M. Downey

Type: Oral

Year: 2012