一种新型的亚硝酸根离子选择性电极的制备及其特性

Preparation of a New Type of Nitrite Ion-selective Electrode and its Characteristics

在一种特殊的钨酸空心管的基础上制备了一种结构简单且灵敏的亚硝酸根离子选择性电极。其线性响应范围是20ng/ml—5pg/ml NO_2~—,斜率约为68mV,此线性功能至少在电极连续使用时能保持三个月左右。电极的一些特性,如pH值的影响,选择性,响应时间,电极内阻,漂移,寿命及其存放等均已经过测试。该电极的是大特点是低至2.8×10^(-5),即大量的NO_3~—存在时一般不干扰NO_2~—的测定。

A new type of simple and sensitive nitrite ion-selective electrode based on the special tungstic acid hollow tube has been prepared. The linear response of the NO_2^- ion-selective electrode is over the range of 20 ng/ml to 5μg/ml for nitrite ion with a slope about 68 mV. The slope of the calibration graph remains constant for at least 0.25 a Characteristics of the ion-selective electrode, such as optimum pH value of the ionic strength adjustment buffer solution, selectivity, response time, internal resistance, electrode storage, drift and lifetime, have been systematically examined. A surprising success is the selectivity coefficient, K_(NO2)^(pot), NO3, as low as 2.8×10^(-5).