Cytostatic drugs (CD), characterized by their environmental persistence have been detected in water
bodies at concentrations up to μg/L levels.1 Several methods for the removal and degradation of CDs,
have been developed,2
but they are relatively expensive and sometimes inefficient for CDs complete
removal from the treated water. Among CDs, platinum-based chemotherapy agents are widely used
for the treatment of a variety of cancers and demonstrate a high toxicity and low biodegradability.
Such compounds, after administration, are excreted into hospital wastewater intact or as toxic
metabolites in significant percentage.1 Effectively, Pt-based drugs have been detected in the mg/L
range in hospital effluents and water treatment plants, raising concerns about the long-term exposure
of living organisms to low levels of such compounds.
A potentially efficient strategy to treat such low levels of Pt-containing contaminants is to selectively
pre-concentrate the sample by adsorption, and then to further treat it e.g., by means of advanced
oxidation processes.
In this contribution, the adsorption of cisplatin by dithiocarbamate (DTC) modified silica is evaluated.
The choice of this material is based on the high affinity of the thiocarbamate group for Pt2+, which,
upon metal binding, causes the destruction of the original toxic compound. Also, the low-cost starting
materials for the preparation of the adsorbent phase makes it attractive from an economic point of
view.
The functionalization of silica was carried out with a slightly modified literature procedure3
and
characterized by IR, TGA and PZC analysis. Adsorption kinetics and isotherms have been built by
analysing the free concentration of Pt by using UV-Vis spectrophotometry. The obtained material
showed that equilibrium was reached after about 60 minutes of contact time with the cisplatincontaining solution. The mass/volume ratios between 1 and 10 mg/mL of adsorbent were tested. The
adsorbent material retained up to 70% of the platinum present in the experimental conditions adopted.
References
[1] Roque-Diaz Y. et al. Processes, 2021, 11, 9, 1873
[2] Pieczyńska, A. et al. Crit. Rev. Env. Sci. Tech., 2017, 47, 1282
[3] Goubert-Renaudin, S. New J. Chem., 2009, 33, 528–537
