Evaluation of toxicity and bioaccumulation of metals from transport and their effect on the mineral composition of green alga Desmodesmus subspicatus using ICP MS/MS

Ecotoxicological tests on green alga Desmodesmus subspicatus are used to determine the toxicity of environmental samples. Since green algae are among the primary producers in most of aquatic food chains, harmful pollutants accumulated in the algae can be transmitted to higher trophic levels. A method for analysing the bioaccumulation of chromium, zinc, potassium, phosphorus and sulphur (Cr, Zn, K, P, S) by the unicellular alga D. subspicatus using ICP-MS/MS has been optimized. Cr and Zn were selected as elements originating from transport; K, P and S are among the basic mineral elements. Bioaccumulation was monitored during a 72-h ecotoxicological test, which made it possible to assess the relationship between sample toxicity, accumulation of pollutants in algae and a change in the content of selected elements in algal cells. For testing, potassium dichromate (K2Cr2O7) and aqueous extract of contaminated sediment were selected. It was found that with increasing concentrations of the toxicant, the concentration of Cr and Zn in the algal cells increased, with the most significant increase being observed at the EC50 concentration corresponding to a 50% growth inhibition; on the other hand, the content of K in cells gradually decreased to values below the detection limit of ICP-MS/MS at the highest concentrations of the toxicant. For sulphur, the concentration in the cells was increased up to the EC50 concentration and then decreased; the content of P in cells increased with the increasing toxicant concentration.

Automated summary

Ecotoxicological tests on green alga Desmodesmus subspicatus were conducted to determine the toxicity of environmental samples. A method using ICP-MS/MS was optimized for analyzing the bioaccumulation of chromium, zinc, potassium, phosphorus, and sulphur by the algae. The results showed that the concentration of Cr and Zn in the algal cells increased with increasing concentrations of the toxicant, while the concentration of K decreased and the concentration of sulphur initially increased and then decreased. The concentration of P in the cells increased with increasing toxicant concentration.