毆殺松及其代謝物達馬松在水稻之殘留消退分析

Dissipation of Acephate and Its Metabolite Methamidophos in Rice

楊尚勳(Shang-Hsun Yang) ； 呂惠鈴(Hui-Ling Lu) ； 黃慶文(Ching-Wenn Huang) ； 蔡銘原(Ming-Yung Tsai) ； 徐慈鴻(Tsyr-Hong Shyu)

《臺灣農藥科學》 3期 (2017/12) Pp. 39-47

https://doi.org/10.6671/TPS/2017.003.03

摘要

本研究依據殺蟲劑毆殺松(acephate)在田間推薦之施藥方法，採用逆向殘留消退試驗設計(reversed decline trial design)，在適當面積之水稻田區中，除空白對照區外，規劃7個獨立試驗田區，分別於採收前0、7、14、21、28、35及42天進行施藥試驗，並於稻穀收穫期一起採樣。殘留分析樣品為稻穀與糙米。結果發現稻穀中毆殺松殘留量施藥當天為1.28 mg/kg，施藥後28天，有0.63 mg/kg之殘留，施藥後42天之殘留量已降至0.05 mg/kg。稻穀中毆殺松代謝物達馬松(methamidophos)殘留量施藥當天為0.05 mg/kg，施藥後28天，殘留量上升至0.12 mg/kg，施藥後42天之殘留量已降至0.01 mg/kg。糙米中毆殺松殘留量施藥當天為0.02 mg/kg，施藥後28天，殘留量上升至0.14 mg/kg，施藥後42天之殘留量已降至定量極限(limit of quantification, LOQ) 0.01 mg/kg以下。糙米中毆殺松代謝物達馬松殘留量施藥當天為定量極限以下，施藥後28天，殘留量上升至0.14 mg/kg，施藥後42天之殘留量已降至定量極限以下。目前米類上毆殺松的殘留容許量0.5 ppm、達馬松的容許量0.1 ppm。毆殺松在水稻安全採收期為10天。建議毆殺松安全採收期延長(例如42天)或提高達馬松容許量至0.15 mg/kg以上。

關鍵字

毆殺松 ； 達馬松 ； 殘留 ； 水稻

並列摘要

In this study, a reversed decline trial design was used to evaluate the residues of insecticide acephate and its metabolite methamidophos in rice. For this, we sprayed acephate on seven rice paddy harvest blocks, except a block for blank reference, at 0, 7, 14, 21, 28, 35, and 42 days before harvest. Paddy rice and brown rice were both sampled for insecticide residue analysis. Acephate and methamidophos were extracted according to the ＂Method of Test for Pesticide Residues in Foods-Multiresidue Analysis - (5),＂ announced by the Taiwan Food and Drug Administration. In paddy rice, our analytical results revealed that acephate residues declined from 1.28 to 0.63 mg/kg over the course of 28 days and to 0.05 mg/kg over the course of 42 days. Conversely, methamidophos residues on paddy rice increased from 0.05 to 0.12 mg/kg over 28 days and then declined to 0.01 mg/kg over 42 days. In brown rice, acephate residues increased from 0.02 to 0.14 mg/kg over 28 days, but decreased to below the limit of quantification over 42 days. Methamidophos residues on brown rice increased from below the limit of quantification to 0.14 mg/kg over 28 days, but again decreased to below the limit of quantification over 42 days. According to recent regulation, the maximum residue limits (MRL) of acephate and methamiphos are 0.5 mg/kg and 0.1 mg/kg, respectively, and the pre-harvest interval (PHI) is 10 days after the last application of acephate 75% SP on rice. According to the results of this study, we suggest that, for rice, the PHI of acephate should be adjusted to more than 10 days (e.g., 42 days), or the MRL of methamidophos should be increased to more than 0.15 mg/kg.

並列關鍵字

acephate ； methamidophos ； residue ； rice