Deveropment of a continuous monitoring system for an acid rain based on null-point potentiometry

(1)本文提出了一种新的甘氨酸/盐酸缓冲液（pH2.80），用氟离子选择性电极检测器连续流动分析系统测定水中微量游离氟。(2)研制了一种以浴铜灵硝酸铜为离子交换剂的硝酸根离子选择性电极，并应用于酸雨中硝酸根浓度的时程观测。(3)研制了一种基于零点电位法的酸雨硝酸盐连续流动分析系统。在该系统中，硝酸根离子选择性膜基于三十烷基甲基硝酸铵离子交换剂被用作检测器。样品侧和标准侧之间的膜电位自动保持为（]sy. ±-. [)1通过控制KNO 3标准溶液的稀释率，样品溶液注入流动系统后5- 10分钟显示其浓度。五次独立测量的准确度和精密度均在5%以内。该系统已应用于雨水分析。

(1) A new buffer based on glycine/HCL pH2.80 was proposed for the determination of very low concentrations of free-fluoride in eain water, by using the continuous-flow analysis system with a fluoride ion-selective electrode detector. (2) A new nitrate ion-selective electrode based on his (bathocuproin) copper (II) nitrate ion-exchanger was developed and applied to the time-course observation of nitrate concectration in an acid rain by using the continuous-flow analysis system. (3) A novel continuous-flow analysis system for nitrate in an acid rain was developed, which is based on null-point potentiometry. In this sytem, a nitrate ion-selective membrane based on triotadecylmethylammonium nitrate ion-exchanger was used as a detector. The membrane potential between the sample and standard sides was kept automatically so as to be (]sy.+-.[)1 mV by controlling the dilution rate of a standard KNO3 solution. The concentration of a sample solution is displayd 5-10min after its injection into the flow system. The accuracy and precision of the independent five measurements were within about 5%. This system was applied to rain water analysis.