Development of the method for environmental assessments based on the recognition of the correlation between the speciation of trace metals and the response by living organisms

在该项目的早期阶段，对痕量金属形态的基本原理进行了研究，并建立了钙黄绿素蓝吸附捕集的方法。用该方法对金属离子进行了灵敏的测定，镉和铅离子的检出限分别为0.05和0.04 nm。对于不同的淡水样品，上述金属离子的浓度可很容易地直接测定到0.2-4 nm。其次，为了了解不稳定和惰性络合物的每个浓度，在测量之前必须分解溶解的有机化合物。当金属离子浓度很低时，分解过程必须在无污染的条件下进行。建立了低压汞灯下紫外光分解的方法。用该方法可以在无污染的c-…下成功地分解用于电化学测量的干扰化合物，如芳香族化合物、腐植酸、氨基酸等。更多的条件。此外，我们还试图制定了解生物体对各种金属络合物的反应的物理化学标准。腐植酸是天然水中的配位体。用吸附伏安法测定络合容量和条件稳定常数K‘&lt；L1&gt；，可以得到不同检测窗值下不同的络合容量和条件稳定常数K’&lt；L1&gt；对于镍离子，在pH为8.5时，当logα、ML2和6.73分别为4.73、5.93和6.73时，测得c1和lt；分别为14.1、8.7和8.3 nM/ppm，logK‘和12.2、13.6和14.5。随着logAlpha；ML2&gt；的增加，c&lt；L1&gt；减小，而logK‘&lt；ML1&gt；增加。这表明腐植酸中的官能团具有广泛的配位能力。在这一阶段，有人提出了这样一种可能性，即有了logAlpha；ML2和Gt；，可以用广义数值来识别生物对金属离子的反应。较少

At the early stage of this project fundamentals of the trace metal speciation were investigated and the method for adsorptive collection with Calcein-Blue has been established . Using this method, metal ions were determined sensitively and the limit of detection for cadmium and lead ion were 0.05 and 0.04nM,respectively. For various fresh water samples, the concentrations for above metal ions were directly determined to be 0.2-4 nM with great ease. Secondly, to know each concentration for labile and inert complexes, dissolved organic compounds have to be decomposed before measurements. When the concentrations of metal ions are very low, the decomposition process have to be done under non-contaminated condition. We developed the decomposition method of UV-irradiation with low pressure mercury lamp. With this method , interfering compounds for electrochemical measurements, such as aromatic compounds, humic acids, amino acids, etc, could be decomposed successfully under non-contaminated c … More ondition. Further, we tried to investigate to make the physico-chemical standard to understand the response of living organisms to various metal complexes. Humic acid was represented as the ligand in natural waters. To know the complexing capacity, c_<L1>, and the conditional stability constant, K'_<ML1>, using adsorptive voltammetry, various c_<L1> could be obtained under various values for detection window, logalpha_<ML2>, depends on the ligand for adsorptive collection and its concentraion. For nickle ion, when logalpha_<ML2> was 4.73,5.93 and 6.73 at pH 8.5, c_<L1> was determined to be 14.1,8.7 and 8.3 nM/ppm, and logK'_<ML1>, was 12.2,13.6 and 14.5, respectively. As increasing logalpha_<ML2>, c_<L1> was decreased and logK'_<ML1> was increased. This indicates the functinal groups in humic acids have wide range of ability for coodination. At this stage it has been suggested the possibility that, with logalpha_<ML2>, the response of living organisms to metal ion could be recognized by generalized numerical values. Less