Date of Award
Master of Science in Environmental Engineering - (M.S.)
Civil and Environmental Engineering
R. P. T. Tomkins
Richard B. Trattner
Barbara B. Kebbekus
Toxic metals are present in the environment and are known to be present in food. Selenium, which is considered an essential micronutrient, is recognized as a toxic metal at slightly higher concentrations. Arsenic is also recognized as a toxic metal. Selenium and Arsenic tend to accumulate in food, specifically fish and seafood.
Fifteen brands and types of tuna fish were analyzed for selenium using differential pulse cathodic stripping voltammetry. The cans with the high and low concentrations of selenium were analyzed for arsenic using differential pulse polarography. Three samples with three percent recoveries and a blank were analyzed for each can of tuna fish. Four sample digestion methods with several variations of each were tested to determine the most reliable technique. An acid digestion procedure using HNO3 and Mg(NO3)2.6H2O with an 18 hour predigestion step gave the best results with an average recovery of 98.2 percent.
The selenium concentration of the cans analyzed ranged from 0.034 to 1.20 µg/g with an average concentration of 0.68±0.268 µg/g. The arsenic concentrations of the two cans analyzed were 1.62 µg/g and 2.41 µeg in the low and high selenium cans respectively.
The selenium concentrations found in the tuna fish are not excessively high and do not seem to pose a problem. The arsenic concentration of 2.41 µg/g does however approach the maximum allowable level set by the FDA at 2.6 ppm.
Higham, Ann Marie, "Determination of trace quantities of selenium and arsenic in canned tuna fish using electroanalytical techniques" (1985). Theses. 1991.