This thesis is the development of a method for detection and quantitative determination of trace levels of metal ions in complexing and non-complexing media. The purpose of this work was threefold: (a) the development of the thin layer cell and the mathematics that describes it, (b) the application of the cell to the detection of trace metals and (c) the study of the strength of complexes of metal islands formed with ligands such as may be found in natural waters.