1. Determination of Manganese in Biological Samples. 2. Studies of the Effects of Aluminum and Decaying Vegetation on Aquatic Life Exposed to Acidity.

Part One. Determination of Manganese in Sweat and Urine. A method has been developed for the direct determination of manganese in perspiration using graphite furnace atomic absorption spectroscopy. This method was applied to a study of manganese concentrations in perspiration and urine samples. Concentrations of manganese found in sweat were significantly higher than the concentrations in urine. Determination of the chemical form of manganese in sweat was attempted. Analysis of sweat using anodic stripping voltammetry strongly indicated that the manganese was organically bound. In addition the potential of interfacing liquid chromatography and inductively coupled plasma emission spectroscopy for the speciation of metal complexes was shown. Part Two. Effects of Aluminum and Decaying Vegetation on Aquatic Life Exposed to Acidity. Acid rain is a pollutant that can kill fish and other form of aquatic life. At pH 7.0 the fish survived irrespective of the aluminum concentration. However, at pH 5.0 and 4.5 the presence of aluminum increased toxicity. The decomposition products of leaves had several modifying effects on the toxicity of pH and aluminum. Decaying leaves increased the pH of water from 4.5 to about 6, which is considered to be a safe pH for fish survival. In addition, the buffer capacity of the waters increased significantly. A method for the speciation of aluminum in freshwater was developed using Chelex-100. This method allowed the determination of ionic forms and organically complexed forms of aluminum. This method was applied to the study of aluminum in leafwater. The degree of complexation varied with the leaf species and the concentration of the decomposition products. Furthermore, the effect of leaf decomposition products on the toxicity of aluminum was investigated at pH 4.5 and 5.0. Leafwater had no effect of the toxicity of 100 ppm aluminum and pH 4.5. However, leafwater was observed to mitigate the toxic synergistic effect of aluminum at pH 5.0. The toxic effect of aluminum on fish was significantly decreased presumably because the decomposition products complexed the aluminum creating a non-toxic form. This work has provided a basis for further study and may lead to the formulation of a natural buffering or complexing agent capable of providing protection to our lakes and waterways