Temporal decrease of trivalent chromium concentration in a standardized algal culture medium: experimental results and implications for toxicity evaluation.

The fate of two trivalent chromium salts (nitrate and chloride) in ISO algal culture medium was followed over 72 h; i.e., the typical duration of algal toxicity tests. Fifty percent of the initial Cr spikes was lost from the solutions by 24 h, with losses up to 90% after 72 h. Monitoring of the temporal variability of Cr(III) concentrations in algal culture media appears necessary to better characterize the toxicity of trivalent chromium to algae.