毛细管扩散微滴定方法研究

提出一种新型的微滴定技术 :滴定试剂经毛细管扩散到样品溶液完成微滴定过程 ,通过指示剂的变色情况来判断微滴定终点 .通过对影响毛细管扩散微滴定扩散速率各项因素分析 ,在相同的试剂贮液器液位高度和搅拌速率的情况下 ,扩散速率只与毛细管的内径、长度等特性有关 ,而与待测样品溶液初始浓度、滴定反应类型无关 ,为计时法计量微滴定试剂用量提供了依据 .同时 ,对称重法和计时法所得的结果进行了比较 ,两者的相对误差均小于 1 .2 % ,方法的重现性较好

Development of diffusional capillary micro-titration

A novel micro\|titration method was developed by using fused silica capillary column as volumetric micro\|burette, acid\|base titration and oxidation\|reduction as the main types. The effects of many factors on diffusion rate are also studied. The results show that the diffusion rates are only related to the inner diameter and length of capillary column at the same level of reagent reservoir and magnetic stirring speed. In practical operation, diffusion rate may be simply changed by adjusting the length or inner diameter of capillary column to suit an appropriate determination. The relative error between weighing method and recording\|time method is lower than 1.2%. Using this device to finish acid\|base titration and oxidation\|reduction will be simple in operation, cost\|less in apparatus, reliable in measurement.