Abstract
A study was undertaken to investigate the absorption, translocation and metabolism of carbofuran in rice paddies. Ring-3-$^{14}C-carbofuran$ applied onto the paddy soil surface was rapidly absorbed and translocated into rice plants. Within 2 days after treatment, it was observed that carbofuran reached shoot tips and accumulated. More than 15% of total radioactivity was recovered in rice plant from 3 to 20 days after treatment. In organic soluble fraction of rice plant extract, 3-hydroxycarbofuran was the major metabolite recording 43% and 4% of total organic soluble radioactivity in shoot and root at 20 days respectively. 3-Ketocarbofuran and phenolic metabolites including carbofuran phenol, 3-hydroxycarbofuran phenol and 3-ketocarbofuran phenol were also detected in the organic soluble fractions. Some glycosidic conjugates of carbofuran metabolites were found in water soluble fraction of rice plant extract and 3-hydroxycarbofuran was the most abundant aglycone. Radioactivity in paddy soil was rapidly decreased until 3 days after treatment and then maintained almost constant level. A significant portion (42∼56 %) of the total radioactivity remained in soil as nonextractable residue from 5 to 20 days after treatment. The nonextractable radioactivity was mainly located in soil organic matter distributing in humin, fulvic acid and humic acid fractions with the decreasing order. Evolution of $^{14}CO_2$ from ring cleavage of $3-^{14}C-carbofuran$ was negligible recording only 1.8% of total radioactivity during 20 days after treatment.
수도체(水稻體) 및 담수토양중(湛水土壤中) carbofuran의 행적(行跡)을 구명(究明)하기 위하여 토양표면(土壤表面)에 $3-^{14}C-carbofuran$을 처리(處理)하고 시기별(時期別)로 수도체(水稻體)로의 흡수(吸收), 이행(移行) 및 대사양상(代謝樣相)을 조사(調査)하였다. 토양표면(土壤表面)에 처리(處理)한 carbofuran은 근부(根部)를 통(通)하여 수도체내(水稻體內)로 신속히 흡수(吸收), 이행(移行)되었으며 처리(處理) 후(後) 2일이내(以內)에 엽선단(葉先端)에 도달하고 축적(蓄積)되는 경향(傾向)을 보였다. 약제처리(藥劑處理) 20日 후(後) 수도체(水稻體)로 흡수(吸收)된 방사능(放射能) 총(總) 처리방사능(處理放射能)20%이상(以上)었다. 수도체중(水稻體中)arbofuran의 주요(主要) 대사산물(代謝産物)은 3-hydroxycarbofuran이었고, 3-ketocarbofuran 및 3종(種)의 phenol성(性) 대사물(代謝物)이 검출(檢出)되었다. 수용성(水溶性) conjugates의 대부분(大部分)은 glycoside결합형태(結合形態)이었으며 주요 aglycon은 3-hydroxycarbofuran이었다. 토양중(土壤中) 방사능(放射能)은 처리(處理) 3日 후(後)까지는 빠른 속도(速度)로 감소(減少)하였으나 그 이후(以後) 거의 일정(一定)한 수준(水準)을 보였다. 비추출성(非抽出性) 방사능(放射能)은 시간(時間)이 경과(經過)함에 따라 증가(增加), 처리(處理) 20일(日) 후(後) 총(總) 처리(處理) 방사능(放射能)의 50%이상(以上)을 차지하였으며 유기물(有機物) 분획별(分劃別) 분포(分布)는 humin>fulvic acid>humic acid 순(順)이었다. B두캐력무 ring의 개열반응(開裂反應)에 의한 $^{14}CO_2$방출(放出)은 처리(處理) 후(後) 20일(日)까지 1.8%로 미미한 수준(水準)을 나타내었다.