Shi Kaiwei, Wu Xujin, Ma Jingwei, Zhang Junfeng, Zhou Ling, Wang Hong, Li Li
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences , Beijing 100101, China.
Henan Academy of Agricultural Sciences/Henan Key Laboratory of Grain Quality and Safety and Testing/Laboratory of Quality Safety Risk Assessment for Agro-products (Zhengzhou), Ministry of Agriculture, Institute of Quality Standard and Testing Technology for Agro-products , Zhengzhou 450002, China.
J Agric Food Chem. 2017 Dec 6;65(48):10439-10444. doi: 10.1021/acs.jafc.7b03916. Epub 2017 Nov 21.
The yam (Dioscorea spp.) is widely cultivated in China. The degradation of dithianon and pyraclostrobin in yams with different planting and processing treatments was investigated in this article. An analytical method for two pesticides in yam and yam plant was developed, and recoveries were between 77% and 93%, with relative standard deviations from 0.8% to 7.4%, respectively. On the basis of this method, half-lives for plants grown on stakes versus plants grown without stakes were compared. The results indicated that the half-life for pesticide residues for plants grown on stakes versus plants grown without stakes differed as 6.7 versus 3.1 days for dithianon and 5.4 versus 5.2 days for pyraclostrobin. Dithianon was significantly influenced by planting mode because of its low stability under sunlight. The processing factors of various processing treatments (hot air-drying, vacuum freeze-drying, microwave vacuum-drying, infrared-drying, steaming, and boiling) were all <1, indicating that those processes can reduce residues of two pesticides at different levels. Significant amounts of residues were removed during the boiling treatment, whereas the others showed less effect.
山药（薯蓣属）在中国广泛种植。本文研究了不同种植和加工处理的山药中二硫氰基甲烷和吡唑醚菌酯的降解情况。建立了一种测定山药及其植株中两种农药的分析方法，回收率在77%至93%之间，相对标准偏差分别为0.8%至7.4%。基于该方法，比较了搭架种植的植株和未搭架种植的植株中农药的半衰期。结果表明，搭架种植的植株与未搭架种植的植株相比，二硫氰基甲烷农药残留的半衰期分别为6.7天和3.1天，吡唑醚菌酯分别为5.4天和5.2天。由于二硫氰基甲烷在阳光下稳定性较差，其受种植方式的影响显著。各种加工处理（热风干燥、真空冷冻干燥、微波真空干燥、红外干燥、蒸煮和水煮）的加工因子均<1，表明这些加工过程能在不同程度上降低两种农药的残留量。水煮处理过程中去除了大量的残留，而其他处理效果较小。
