基于多相荧光动力学曲线特征的水质生物毒性综合表征参数构建

Construction of Synthetic Characterization Parameters of Biotoxicity of Water Quality Based on Characteristics of Multiphase Fluorescence Kinetic Curve

基于藻类光合抑制效应的水质生物毒性检测方法,具有响应快速、测量简捷等优点。然而现有十多种光合荧光参数都源于PSⅡ光合反应中心,对典型的PSⅠ光合作用抑制剂,均表现出响应灵敏度差或无响应。利用毒性胁迫会引起藻类荧光动力学曲线发生变形、且变化程度与毒性强度成正比的特性,直接以多相叶绿素荧光动力学曲线形态为分析对象,在准确定位特征位点的基础上,构建基于曲线分段抑制的综合表征参数CPI,并与常用的光合荧光参数Fv/Fm以及性能指标PI_(abs)进行毒性响应时间、响应灵敏度和稳定性的对比分析。结果表明,综合参数CPI对于PSⅡ抑制剂阿特拉津,15 min即在全样本表现出显著性抑制,最低检测限和RSD分别为2.25μg·L^(-1)和8.76%,对比PI_(abs)、Fv/Fm分别降低了51.8%、51.3%和68.0%、17.7%。对于典型PSⅠ抑制剂百草枯,综合参数CPI在15 min表现出显著性抑制,对应的检测限和RSD分别为0.16 mg·L^(-1)和14.25%,而参数Fv/Fm无响应,CPI具有时间响应优势;在8 h长时抑制下,CPI对应的最低检测限和RSD分别为0.09 mg·L^(-1)和3.30%,对比PI_(abs)、Fv/Fm分别降低了71.9%、62.5%和75.6%、30.0%。上述结论表明了综合参数CPI作为响应指标可用于检测PSⅠ及PSⅡ抑制剂的生物毒性,且表现出良好的响应灵敏度和稳定性,解决了藻类光合抑制法对PSⅠ抑制剂响应灵敏度低的问题,且对于统一不同种类毒性物质的毒性响应指标提供了关键参数。

There are advantages of quick response and simple measurement in the water biological toxicity detection method based on the photosynthetic inhibition effect of algae.However,more than ten photosynthetic fluorescence parameters are derived from the PSⅡphotosynthetic reaction center,showing poor sensitivity or no response to typical PSⅠphotosynthetic inhibitors.In this paper,based on the characteristic that toxic stress will cause deformation of algae fluorescence kinetics curve,and the change degree is proportional to the toxicity intensity,the morphology of the multiphase chlorophyll fluorescence kinetics curve is directly taken as the analysis object.Based on the accurate location of the characteristic sites,a comprehensive characterization parameter CPI based on the segmentation inhibition of the curve is constructed.The toxicity response time,response sensitivity and stability were compared with the commonly used photosynthetic fluorescence parameters Fv/Fm and the comprehensive fluorescence parameter PIabs.The results showed that for paraquat,a typical PSⅠinhibitor,the comprehensive parameter CPI showed significant inhibition at 15 min(1 mg·L^(-1) and above),while Fv/Fm had no response.Compared with PI_(abs) and Fv/Fm,the minimum detection limit and relative standard deviation decreased by 70.3%and 24.1%and 75.6%and 30.0%,respectively,under 8h stable inhibition.Atrazine,a PSⅡinhibitor,showed significant inhibition in the whole concentration range of samples within 15 min,and the minimum detection limit and relative standard deviation decreased by 52.4%and 51.6%and 75.6%and 30.0%,compared with PI_(abs) and Fv/Fm.These conclusions indicate that the comprehensive parameter PICTE,as a response index,can be used to detect the biotoxicity of PSⅠand PSⅡinhibitors,and it shows good response sensitivity and stability.The results of this study provide an important parameter for highly sensitive and high-precision detection of biotoxicity in water based on algae photosynthetic inhibition.