离子电极用于煤基甲醇溶液中微量铬的测定

Ion electrode for determination of trace chromium in methanol based on coal

以3-甲氧基噻吩-2-甲醛和邻苯二胺合成的席夫3-甲氧基噻吩-2-甲醛缩-邻苯二胺为中性载体,将其与碳粉混合,以液体石蜡为粘合剂,制备了新型的铬(Ⅲ)离子选择性电极。室温下,电极对Cr3+的能斯特响应范围为4.00×10^-7~1.00×10^-2mol/L,斜率为18.23mV/dec,检出限为3.02×10^-7 mol/L。电极响应时间小于20s,pH使用范围广(3.30~5.00),稳定性好,使用寿命长。在选定的条件下,考察了10余种离子的干扰情况,并利用该离子选择性电极对煤基甲醇中的Cr3+进行了测定,取得了较好结果。

A carbon film based on 3-methoxythiophene-2-carbaldehyde-o-Phenylenediamine synthesized using the rection of 3-methoxythiophene-2-carbaldehyde with o-phenylenediamine as a film carrier, was prepared and investigated as a Cr(Ⅲ)-selective electrode. The electrode has a linear dynamic range of 4.00 ×10-7~1.00 ×10-2 mol/L, with a near Nerstian slope of 18.23 mV per decade and a detection limit of 3.02×10-7 mol/L. It has a fast response time of about 20 s and could be used for long time successfully. The potential of this electrode is independent of pH in the range of 3.30-5.00, and it also exhibits a very good selectivities for Cr(III) over a wide variety of metal ions. The electrode has been used to determine the chromium contents in methnol based on coal, and the result is excellent.