Element analysis of algae treated with F − or arsenite

Abstract

The multi-element analysis by proton induced X-ray emission and proton induced γ-ray emission has been used to follow the element concentrations in algae when the toxins F − or arsenite were added to their growth medium. The analysis was done in air on cells deposited on thin filters. Both toxins produced a lag phase in the growth curve of the culture. The F concentration rose initially and then decreased, suggesting that the cells adapted by expelling the toxin. Furthermore, with F −, the concentrations of other elements, except K for which there was almost a complete loss in a medium of 150 ppm F, follow the changes observed in an untreated culture. The level of As initially rose and then remained constant. No changes in the concentrations of the other elements caused by this toxin were observed. In an attempt to determine whether As was tightly bound to a large molecule in the cell, the filtered algae were treated with several reagents and the concentration of As left in the algae was determined. The results indicated that As is not immobilized in the cells.