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Tin (Sn) is one of the heavy metals to which various functions in biological development are attributed in small quantities, for example, a role in cell structure, enzyme activities, and protein and carbohydrate metabolism in fish. Tributyltin (TBT) and triphenyltin (TPT) are endocrine disrupting chemicals that are widely distributed in the aquatic environment. The aim of this study was to investigate the effects of TBT, TPT, and SnCl2 on the embryonic development of zebrafish. In this study, zebrafish embryos were used to observe the acute toxicity of TBT, TPT, and SnCl2. Fish embryo toxicity analysis was performed for different TBT, TPT, and SnCl2 concentrations (1, 5, 10, 15, and 20 ng/L). Fertilized eggs in 24‐well plates (20 eggs in each concentration) were incubated at 26°C for 4 days, and embryo clotting, embryo heartbeat, and morphological abnormalities were recorded after 96 h. Coagulation increased significantly in a dose‐dependent manner, and TBT was able to induce coagulation in zebrafish embryos. Heartbeat changes significantly decreased (p < 0.05) in a dose‐dependent manner at different TBT doses (p < 0.05). The percentage of mortality was higher in embryos at trace levels of TBT, indicating that the embryos are more sensitive to the toxicity of TBT. TBT is therefore extremely toxic and can have fatal consequences for zebrafish embryos, ultimately leading to the extinction of species and a decline in biodiversity in the aquatic environment. After analyzing the images 96 h after fertilization and converting them to a teratogenic index score, it was found that the index for the two compounds TPT and TBT was 4.6 and 9.6 ng/L, respectively. [ABSTRACT FROM AUTHOR]

In this study, the degradation of two organophosphate pesticides, namely, propetamphos and azamethiphos, in the presence of Ag+ at different mole ratios was investigated. Moreover, the kinetic and degradation pathways of both chemicals in the range of 0–60 min were explored. Gas chromatography equipped with a thermionic specific detector was used to investigate the pesticide degradation kinetics and mechanism. The results show that the degradation rate of both pesticides follows first-order kinetic. The first-order rate constant and the half-life of reaction were in the range of 0.002–0.143 min−1, 187–2.1 min, and 0.005–0.164 min−1 and 60–1.8 min, for propetamphos and azamethiphos, respectively, at ambient temperature (25 ºC). Because group containing sulfur atom is a better leaving group than group containing nitrogen, the rate of degradation of azamethiphos is higher than propetamphos. In a higher mole ratio of Ag+ to pesticides, the degradation rate was increased, and it is possible to predict the rate of degradation of pesticides according to the chemical composition of leaving group. [ABSTRACT FROM AUTHOR]