摘要：

以自制的液滴体积为0.01～0.02 mL的聚乙烯毛细滴管同时测定水中硫酸根和总硬度, 仪器外形小巧、便于携带, 滴定快速、准确, 试剂消耗量约为常量法的5%, 滴定剂用量约为50～200滴, 硫酸根含量不确定度为0.94%, 与重量法相当, 相对标准偏差比重量法的略小;水中总硬度不确定度为0.82%, 效果也优于常量法。该法克服了常量法中滴定管、移液管、铁架台和蝴蝶夹等仪器携带不方便的不足, 适用于工业用水现场和野外水质的快速分析。

关键词: 毛细滴管, 微型滴定法, 硬度

Abstract:

A drop counting analytical method used in simultaneous determination of the SO₄^2- and total hardness in water by home-made polyethylene capillary burette of 0.01-0.02 mL per drop has been studied. The apparatus is mainly characterized by small in shape, convenient to be carried and fast and accurate in titration. The reagent consumption is about one twentieth of the ordinary method; the titrant dosage of it is only about 50-200 drops, the related expanded uncertainty of SO₄^2- is about 0.94%, corresponding to that of gravimetric method. The relative error rsd (%)is a little smaller than that of gravimetric method. The related expanded uncertainty of total hardness in water is about 0.82%. The effect is superior to ordinary method. The method overcomes the inconvenience in carrying buret, pipet, buret support, buret holder in ordinary analysis, and is quite suitable for rapid analysis of industrial water quality on site and in field.

Key words: capillary burette, micro titration, hardness

中图分类号: 

• X832

• O655.21