本研究根據丁基拉草抑制植物生長之原理，嘗試利用生物檢測技術取代精密儀器以偵測除草劑。從種子抑制發芽之反應顯示白莧對於10.3 mM丁基拉草濃度相當敏感，於處理後2天即達到100%抑制效果。分析芥菜及白莧下胚軸生長抑制反應顯示10.3 mM丁基拉草處理後兩天可以抑制其生長達80-82%。此外，這兩種蔬菜其胚根生長對於丁基拉草亦有相同反應，分別抑制達86及89%。進一步利用劑量反應分析可以發現白莧種子發芽、或芥菜及白莧之下胚軸與胚根生長，與丁基拉草濃度之對數值呈現線性回歸關係。另一方面，利用有機溶劑萃取及高效液相層析系統分析，在供試樣品含0.02-0.10 mM丁基拉草範圍內，儀器積分面積與濃度呈現線性回歸關係，其偵測丁基拉草之敏感度高於生物檢定10倍。本研究利用事先注入102.9 μmole丁基拉草之20 g土壤為測試材料，比較生物檢定與儀器分析二者之效果差異，結果顯示前者以白莧種子發芽作為檢定指標可以預測出63%丁基拉草濃度，故此生物檢定技術可推薦給農民或種植者運用，以取代昂貴複雜之HPLC系統，尤其後者必須使用有毒之有機溶劑。

A biological method, based on butachlor inhibitory effect on plant growth, was examined for its application to detect this herbicide without using professional instruments. Analysis of seed germination inhibition showed that edible amaranth was sensitive to 10.3 mM butachlor, with 100% inhibition 2 days after treatment (DAT). Analysis of hypocotyl growth inhibition showed that 2 vegetables including Chinese mustard and edible amaranth, had a similar and constant sensitivity to 10.3 mM butachlor, with 80 to 82% inhibition 2 DAT. In addition, radicle growth inhibition analysis showed that, Chinese mustard and edible amaranth were all sensitive to 10.3 mM butachlor, with 86 and 89% inhibition 2 DAT, respectively. Further dose-response analysis indicated that linear regressions existed between seed germination of edible amaranth, or hypocotyl and radical growth of edible amaranth and Chinese mustard, and the log-transformed concentrations of butachlor. For the instrumental detection of butachlor, with organic solvent extraction and HPLC analysis, a linear regression between integrated peak area of HPLC system and butachlor concentration in extraction solution was observed ranged from 0.02 to 0.10 mM, with ten-fold higher detection sensitivity than bioassay system. A comparison of biological with instrumental methods using a 20-g soil spiked with 102.9 μmole butachlor as the test sample showed that bioassay system, especially the seed germination response of edible amaranth having 63% of predicted concentration compared with that determined by instrument, could be recommended to predict butachlor concentration by farmers or growers, to replace the expensive and complicated HPLC system. The latter is also harmful to environment due to the highly toxic organic solvents used as mobile phase for HPLC system.