College of Resources and Environment, Hunan Agricultural University, Changsha, 410128, China.
Department of Entomology, University of Kentucky, Lexington, KY, 40546, USA.
Environ Sci Pollut Res Int. 2021 Aug;28(32):43956-43969. doi: 10.1007/s11356-021-13713-z. Epub 2021 Apr 12.
Dimethomorph is a morpholine broad-spectrum fungicide and effectively controls taro blight, cucumber downy mildew, rice blast disease, and others. Fluopimomide is a newly developed broad-spectrum fungicide to primarily control oomycetes and rhizoctonia diseases. Taro, one of the earliest cultivated crops, is a staple food in Africa, Oceania, and Asia. Recently, a commercial suspension concentrate formulation containing 15% fluopimomide and 25% dimethomorph has been registered in China, the second largest taro producer in the world. The objective of this study was to develop a high-performance liquid chromatography tandem mass spectrometry method to detect the residues of fluopimomide and dimethomorph concurrently in taro samples. The results showed that the average recoveries of fluopimomide and dimethomorph ranged from 83 to 108%, and relative standard deviations (RSD) ranged from 1 to 11%. The limit of quantitation (LOQ) was 0.01 mg kg for the two compounds. The dissipation results demonstrated that both fluopimomide and dimethomorph in taro degraded rapidly in taro fields, and the residues of the two fungicides were below the LOQ within 14 days post-application. The final residue levels of fluopimomide and dimethomorph in taro were lower than 0.066 mg kg 28 days post-application. For dietary risk assessments, the dietary structure of different genders and age of people in China exposure risk assessment and whole diet exposure risk assessment shows that the risk quotient (RQ) values were substantially lower than 100%, suggesting that the long-term risks of fluopimomide/dimethomorph mixed formulation in taro at the recommended dosage were negligible. In summary, our combined results from the dissipation behaviors, terminal residues, and dietary risk assessments provide the critical empirical data for the establishment of the maximum residue levels (MRLs) of the two broad-spectrum fungicides in taro, a traditional food for African, Oceanic, and South Asian cultures.
烯酰吗啉是一种吗啉类广谱杀菌剂，能有效防治芋疫病、黄瓜霜霉病、稻瘟病等。氟吡菌胺是一种新型广谱杀菌剂，主要用于防治卵菌纲和丝核菌病害。芋艿是最早种植的作物之一，是非洲、大洋洲和亚洲的主食。最近，中国登记了一种含有 15%氟吡菌胺和 25%烯酰吗啉的商业悬浮剂，中国是世界上第二大芋艿生产国。本研究旨在建立一种高效液相色谱-串联质谱法同时检测芋艿样品中氟吡菌胺和烯酰吗啉残留的方法。结果表明，氟吡菌胺和烯酰吗啉的平均回收率在 83%至 108%之间，相对标准偏差（RSD）在 1%至 11%之间。两种化合物的定量限（LOQ）均为 0.01mg/kg。消解结果表明，氟吡菌胺和烯酰吗啉在芋艿田中的降解速度均较快，施药后 14 天内两种杀菌剂的残留量均低于 LOQ。施药后 28 天，芋艿中氟吡菌胺和烯酰吗啉的最终残留量均低于 0.066mg/kg。在膳食风险评估方面，中国不同性别和年龄人群的膳食结构暴露风险评估和总膳食暴露风险评估结果表明，风险商（RQ）值均远低于 100%，提示按推荐剂量使用氟吡菌胺/烯酰吗啉混剂在芋艿中的长期风险可以忽略不计。综上所述，我们从消解行为、最终残留和膳食风险评估的综合结果为建立氟吡菌胺和烯酰吗啉在芋艿中的最大残留限量（MRLs）提供了重要的经验数据，这两种杀菌剂是非洲、大洋洲和南亚文化的传统食品。
