沉淀–电位滴定法测定混凝土中氯离子含量

Utilization of Precipitation-Potentiometric Method for the Measurement of Chloride Ion Content in Concrete

摘要: 探究以沉淀–电位滴定法测定混凝土中氯离子含量的可靠性，研究了待测溶液的碱度对测试结果的影响，并与离子色谱法测得结果进行比较。结果表明：当待测溶液未中和时，采用沉淀–电位滴定法测得结果与离子色谱法结果偏差较大，最大偏差接近30%；而将待测溶液用稀硫酸中和后，其滴定结果与离子色谱法测得结果极为接近，最大偏差仅为5.3%。该方法具有较高的可靠度和经济性，且操作简单，可作为测试水泥基材料氯离子含量的标准方法。

Abstract: Precipitation-Potentiometric Method was used for the measurement of chloride ion content in concrete. Effect of solution alkalinity on the testing results was investigated, meanwhile, which was also compared with the results obtained by ion chromatography (IC). The research indicates that the results obtained by Precipitation-Potentiometric Method have great difference with the IC results when the solution was not neutralized by dilute sulphuric acid, and the maximum deviation is closed to 30%. After neutralizing, however, the titration results are very near to the IC results and the maximum deviation is merely 5.3%. All of these show that the Precipitation-Poten- tiometric Method has the features of high reliability, low cost and easy operation, which can be used as the standard method for measuring the chloride ion content in cement-based materials.