The individual IC 50 (the concentrations causing a 50% inhibition of bioluminescence after 15 min exposure) of cadmium ion (Cd) and nine chlorinated anilines to Photobacterium phosphoreum ( P. phosphoreum ) were determined. In order to evaluate the combined effects of the nine chlorinated anilines and Cd, the toxicities of chlorinated anilines combined with different concentrations of Cd were determined, respectively. The results showed that the number of chlorinated anilines manifesting synergy with Cd decreased with the increasing Cd concentration, and the number manifesting antagonism decreased firstly and then increased. The joint toxicity of mixtures at low Cd concentration was weaker than that of most binary mixtures when combined with Cd at medium and high concentrations as indicated by TU Total . QSAR analysis showed that the single toxicity of chlorinated anilines was related to the energy of the lowest unoccupied molecular orbital ( E LUMO ). When combined with different concentrations of Cd, the toxicity was related to the energy difference ( E HOMO − E LUMO ) with different coefficients. Van der Waals’ force or the complexation between chlorinated anilines and Cd had an impact on the toxicity of combined systems, which could account for QSAR models with different physico-chemical descriptors.
Dali Wang,Zhifen Lin,Ting Wang,Zhifeng Yao,Mengnan Qin,Shourong Zheng,Wei Lu
The toxicity of metal oxide nanoparticles (NPs) has aroused great concern over the past few years. However, there still remains the question whether the toxicity of the metal oxide NPs originates from the released ions or the NPs themselves. In this study, the metal ion release of CuO, Fe 2 O 3 , ZnO, Co 3 O 4 , Cr 2 O 3 , and NiO NPs in aqueous media was investigated, and their contributions to the metal oxide NPs’ inhibition on the bioluminescence of Photobacterium phosphoreum were studied. It was found that the ions release of the metal oxide NPs in aqueous media was complex, depending on both the dissolution and adsorption processes of the metal oxide NPs. The relationships between the metal oxide NPs’ antibacterial effects and their released metal ions could be divided into three categories: (1) the ZnO NPs’ antibacterial effect was due solely to the released Zn 2+ ; (2) the CuO NPs’ antibacterial effect originated from both the released Cu 2+ ,and the CuO particles; and (3) the antibacterial effects of Fe 2 O 3 , Co 3 O 4 , Cr 2 O 3 , and NiO NPs were caused by the NPs themselves. Our findings suggest that the ions release and their contributions to the NPs’ toxicity should be considered in the toxicity evaluations of the metal oxide NPs.
危险品化学品经营许可证（带存储）