A novel direct equipartition ray design (EquRay) procedure for toxicity interaction between ionic liquid and dichlorvos.

BACKGROUND, AIM AND SCOPE: Pollutants always co-exist in the environment. Determining and characterizing the interaction among chemicals is an important issue. Experimental designs (ED) play an important role in evaluating the interactions. The main aim of our study is to provide the test and analysis of the toxicity interaction with a novel ED method. MATERIALS AND METHODS: A novel direct equipartition ray design (EquRay) procedure was proposed to effectively and systematically determine the toxicities of binary mixtures on Vibrio qinghaiensis sp.-Q67. Here, one component is ionic liquid, 1-butyl-2,3-dimethylimidazolium chloride (IL1), 1-butylpyridinium bromide (IL2) or N-hexylpyridinium bis(trifluoromethylsulfonyl)imide (IL3), and another is dichlorvos (DIC). The toxicity interaction was evaluated by comparing experiment and additive model together with three-dimension deviation response surface (DRS) analysis. RESULT: Selecting CA as a reference model, the binary mixtures exerted less than additive (antagonism). Most of the deviations occurred in the centre portion of the DRS where the dCA (deviation from CA) values are between -15% and -26% for IL1-DIC and IL2-DIC mixtures and -10% and -15% for IL3 and DIC. Selecting IA as a additive model, IL1-DIC and IL2-DIC mixtures exhibited less than additive (antagonism) while IL3-DIC displayed an addition action and the absolute values of dIAs (deviation from IA) were less than 10%. CONCLUSION: A novel EquRay procedure was developed in this study and the EquRay can provide us with the information about the toxicity interaction between binary mixture components (such as DIC and IL) in different concentration regions across different mixture ratios.