Disperse systems based on chloracetophos in the low concentration range: self-organization, physicochemical properties and influence on representatives of higher plants and hydrobionts

Abstract

A set of physicochemical methods was used to establish that aqueous solutions of chloracetophos fungicide and bactericide (1) in the range of calculated concentrations from 1•10^–18 to 1•10^–4 mol L^–1 are disperse systems in which a dispersed phase hundreds of nanometers in size is formed above and below a threshold concentration of 1•10^–9 mol L^–1. Upon dilution disperse systems 1 are capable of non-monotonic changing the physicochemical properties and changing the toxicity profile (inhibition–stimulation) when influencing the growth and development of unicellular algae Chlorella vulgaris. The formation of domains and nanoassociates is accompanied by the appearance in the UV spectrum of an absorption band at 210–300 nm with a maximum at ~220 nm (A₂₂₀). The interrelated concentration dependences of A₂₂₀, the size of the dispersed phase, and electrical conductivity indicates that the observed spectral features of systems 1 are caused by the properties of the domains and nanoassociates.