安培法流动注射检测器的研制

The Design of an Amperometric Detector for FIA

本文设计了一个用于流动注射分析的安培检测器。它是由金管工作电极,氯化银参比电极和不锈钢管对电极组成。具有结构简单、灵敏度高、重现性好和线性响应范围宽等特点。在我们的实验条件下,总结出了一个描写测量频率的公式:f=vt/(πr^2l+DV_s+KV_9)。对一个固定的测量体系,在一定流速范围内,f仅仅是流速的函数。借助于FIA技术,每小时可完成100次测量。线性响应范围从几个ppb直到几个ppm。相对标准偏差通常不大于3%。对于S~=、Ag+、Hg^(++)和I^-的检出限分别为0.5、2、5和10ppb。该装置适用于某些液体样品中微量电活性物质的监测。

A new amperometric flow-through detector applied to flow injection analysis and continuous flow analysis is designed. It is composed of a gold tubular working electrode, a stainless-steel tubular counter electrode, and a silver chloride referenceelectrode.An expression equation of sampling frequency has been given in this paper as follow:f=ut/(πr^2l+DV_s+KV_g). To a given system analytical rate is only a function of volume fluid velocity.By use of the FIA technique, response is linear for levels from a few tenth microgram to several milligram per liter of sotution.With this approach, analytical rates of 100 samples per hour can be achieved. To S~=, Ag^+, Hg^(++) and I^-,their detection timits are 0.5, 2, 5 and 10ppb respectively, and the relative standard deviations are≤3%. Several factores to effect on limiting current have also been discussed.