目的用叶绿素荧光技术检测除草剂西玛津、扑草净、绿麦隆和敌稗对三角褐指藻液光合信号的抑制效应。方法选择三角褐指藻作为指示生物,通过双通道脉冲振幅调制叶绿素荧光仪检测水样中西玛津、扑草净、绿麦隆和敌稗对藻液光合信号的抑制程度,分析西玛津、扑草净、绿麦隆和敌稗对三角褐指藻液光合信号的单独抑制效应和混合抑制效应。结果除草剂的单独抑制作用由强到弱依次为绿麦隆＞扑草净＞敌稗＞西玛津。在线性范围内除草剂的混合效应等于单独效应之和。超出标准曲线范围,绿麦隆和扑草净的交互作用表现出拮抗效应。西玛津、扑草净、绿麦隆和敌稗的IC50分别为143、18、17.5和53μg/L,标准曲线的相关系数（r）为0.998 5～0.999 9,相对标准偏差均低于15%,自来水加标回收率均值在85.5%～86.3%。结论叶绿素荧光检测技术对西玛津、扑草净、绿麦隆和敌稗对藻液光合信号抑制作用均有很好的响应。该法所需设备体积小,检测速度快,灵敏度高,测试稳定性好,适用于水体农药突发事件应急、检测和预测预报的现场监测。

Objectives:As a indicator of the bioassay technology with ToxY-PAM,the states of growth and biological activity of phaeodactylum tricornutum were key factors for the process of biological detection.To obtain the optimization of culture conditions for phaeodactylum tricornutum,the influence of light intensity,temperature,the concentration of nitrogen and phosphor in culture medium were studied.Methods:The number of cells was counted with hemacytometer and the optimal conditions of culture selecled by comparing relative growth rates under different conditions of culture.Results:The optimal conditions of culture of phaeodactylum tricornutum were: 2000Lux in light intensity,20℃ in temperature,12 mg/L nitrogen and 1.3 mg/L phosphor in culture medium.Conclusion:Under above optimal conditions,phaeodactylum tricornutum grew fast and had a better biological activity.Inhibition of photosynthesis of phaeodactylum tricornutum produced by toxicants in water could be shown exactly.Phaeodactylum tricornutum in these conditions could be used as the indicator of the bioassay technology with ToxY-PAM.