This work evaluated the degradation efficiency of the most used commercial pesticide chlorpyrifos (CP) by UV/H₂O₂ and UVC photolysis processes. Photodegradation was carried out with 200 μg L⁻¹ of commercial CP for 30, 60, 90, 120, 240, 360, and 480 min. The samples were submitted to the liquid–liquid extraction technique and analyzed by HPLC–DAD. Bioassays were performed using two organisms, Daphnia magna and Aedes aegypti larvae, at all the degradation times. The degradation rate was 98% and 99% after 30 min of reaction for the UV/H₂O₂ process and UVC photolysis, respectively. Moreover, during treatment, the main CP by-product, chlorpyrifos oxon (CPO), was identified among other unknown by-products. Acute toxicity with D. magna showed a decrease in the immobility at 480 min by the UV/H₂O₂ process, while in UVC photolysis, 100% immobility was observed for up to 90 min of treatment, and the endpoint oscillated until the end of the process. Bioanalytical monitoring with A. aegypti showed no toxic effects on samples treated by the UV/H₂O₂ process at 60, 90, 120, and 480 min of degradation. Despite the detection of CPO after UVC photolysis from 60 min onwards, no toxicity was verified, indicating that the by-products generated were not toxic to this organism. Therefore, even though high CP degradation rates were reached, for both processes, it was noted that bioassays and the ecotoxicological effect after degradation effluent are important to complement analytical tools.

Graphical abstract

中文翻译：

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商业毒死蜱在 UV/H2O2 和 UVC 光解处理下的毒性测定

这项工作评估了最常用的商业农药毒死蜱 (CP) 通过 UV/H ₂ O ₂和 UVC 光解过程的降解效率。使用 200 μg L ^-1商业 CP进行光降解 30、60、90、120、240、360和 480 分钟。将样品提交给液-液萃取技术并通过 HPLC-DAD 进行分析。在所有降解时间使用两种生物，大水蚤和埃及伊蚊幼虫进行生物测定。UV/H ₂ O ₂反应30分钟后降解率分别为98%和99%分别为工艺和 UVC 光解。此外，在处理过程中，主要的 CP 副产品毒死蜱 (CPO) 在其他未知副产品中被发现。D. magna 的急性毒性显示，UV/H ₂ O ₂过程在 480 分钟时不动性降低，而在 UVC 光解中，观察到 100% 不动性长达 90 分钟的治疗，并且终点一直波动到结束的过程。A. aegypti 的生物分析监测显示对经 UV/H ₂ O ₂处理的样品没有毒性影响60、90、120 和 480 分钟的降解过程。尽管从 60 分钟开始在 UVC 光解后检测到 CPO，但没有验证毒性，表明产生的副产物对该生物没有毒性。因此，即使达到了高 CP 降解率，对于这两个过程，人们注意到生物测定和降解流出物后的生态毒理学效应对于补充分析工具很重要。

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