Environmental context. In the soil environment, microplastics (HDPE) act as carriers to adsorb contaminants, interacting with dissolved organic matter (DOM) and antibiotics such as oxytetracycline (OTC). The results show that DOM plays a bridging role in the HDPE–OTC adsorption system, and its hydrophobic groups are complexed with OTC, resulting in the quenching of DOM ultraviolet spectrum. (Image credit: Qitian Xiao.)

Environmental context. Platinum is a metal of emerging concern in ecotoxicology, mainly due to its dissemination in the environment through the abrasion of car catalysts. However, its aqueous speciation in natural waters remains poorly known, and its binding to organic matter may modify its effects on organisms. Experimental measurements revealed the complex chemistry of Pt, low complexation and very slow kinetics. The use of Pt^II would be recommended for chronic exposure experiments. (Image credit: Océane Hourtané.)