除草劑農藥殺丹（Benthiocarb）在水稻植物中最終產物之分離鑑定   全文下載

Characterization of 14C Terminal Residues in Rice Plants Treated with 14C Ring-Labeled Benthiocarb

除草劑農藥benthiocarb是植物萌前之選擇性農藥，近二十年來被廣泛使用於水稻田以除雜草，為知benthiocarb在水稻中之命運，乃以5磅／英畝之量撒佈14C-benthiocarb於水槽缸，缸內種植水稻成熟收割後，探集稻草和稻米來分析14C量，得知稻草和稻米之14C全量（以benthiocarb計算）各為2.0和3.0 ppm。其中均未檢出含有母體benthiocarb和具有thiocarbamate構造體之代謝產物（<0.01 ppm）存在。稻草中之主要benthiocarb產物為4-chlorobenzoic acid之自由型和結合型的代謝產物（0.25 ppm），其次為含有carboxylic acid和4-chlorobenzylthio構造體之代謝產物（0.33 ppm）。Benthiocarb在稻米中之主要產物為木質素（lignin）結合物（0.28 ppm）和4-chlorobenzyl methyl sulfone （0.02 ppm）。

The terminal 14C residues in rice treated with 14C ring-labeled benthiocarb were characterized. Rice was treated at 5 1b/acre, then grown to maturity. Straw and grain were harvested and analyzed for 14C. The total 14C in the straw and the grain was 2.0 and 0.3 ppm, respectively, calculated as benthiocarb. No (less than 0.01 ppm) parent compound or metabolites containing the intact thiocarbamate moiety were found in either the straw or the grain. Approximately 0.25 ppm 4-chlorobenzoic acid (0.41 ppm 14C calculated as benthiocarb) was isolated from straw as bound, conjugated and/or free metabolites. Two other major 14C metabolites (0.33 ppm), both containing carboxylic acid and the 4-chlorobenzylthio moieties in the molecules, were partially identified. Approximately 0.02 ppm 4-chlorobenzyl methyl sulfone was found in the grain.