Research advances of thioarsenates in the soil-rice system
Thioarsenates have been proved to be important species of arsenic in the soil-rice system,their transformations playing a crucial role in the biogeochemical cycle of arsenic and posing a potential threat to the environment and human health.This article provides a comprehensive overview of the latest research progress on quantitative detection methods,species,influence factors,biogeochemical processes and rice uptake mechanisms of thioarsenates in paddy soil,in an effort to provide methodological references and theoretical foundation for future research.To minimize the transformations of thioarsenates before analysis,diethylenetriamine-pentaacetic acid(DTPA)can be added to the sample,which can be flash-frozen and stored in the dark at low temperature.Ion chromatography coupled to inductively coupled plasma-mass spectrometry(IC-ICP-MS)is suitable for the separation and quantitative determination of thioarsenates in environmental samples.There are significant differences between inorganic and methylated thioarsenates in their formation conditions,environmental behaviors and rice uptake.Concentrations of thioarsenates in paddy soil are affected by many factors such as pH,redox environment and reduced sulfur.Changes of environmental conditions can facilitate transformations between various thioarsenates or between thioarsenates and non-thioarsenic species.Notably,the adsorption capacities of thioarsenates on iron minerals are usually weaker compared with arsenite and arsenate,and thioarsenates show higher instability with the changes of the soil redox conditions.Thioarsenates can be absorbed by rice and accumulated in grains.Dimethymonothioarsenate(DMMTA)exhibits high uptake,transport,and toxicity in rice,and it exist in rice grains and commercial rice globally.Currently,the mechanisms of uptake,transport and detoxification of thioarsenates in rice remain unclear,which is worthy of further research to accurately assess the potential risks of thioarsenates on rice growth,food safety,and human health.
万方数据
维普
