离子色谱法测定减水剂中硫酸钠含量

Ion Chromatography Determination of Sodium Sulfate in Water Reducing Agent

建立了离子色谱法测定减水剂中硫酸钠含量的方法。减水剂试样溶于水中,采用201×7(717)强碱性阴离子交换树脂去除溶液中的有机物,进样量为20μL。在Metrosep A SUPP 5-250型阴离子分离柱上,以3.2 mmol/L Na2CO3和1.0 mmol/LNaHCO3混合溶液作为淋洗液,抑制型电导检测,以0.6 mL/min流量洗脱,按峰面积定量。方法检出限(3S/N)为0.05 mg/L。用标准加入法,以实体为基体进行回收试验,测得回收率为96.3%～104.3%。

Ion chromatography was applied to the determination of sodium sulfate （as SO42） in water reducing agent. The water reducing agent was dissolved in water. 201×7（707） strongly basic anion exchange resin was used to remove organic substances from the sample solution. An aliquot （20 μL） of the eluate from 201×7（707） strongly basic anion exchange resin was taken for IC determination. The Metrosep A SUPP 5-250 column was used for separation, 3.2 mmol/L Na2CO3 and 1.0 mmol/L NaHCO3 solutions were used as mobile phase with flow-rate of 0.6 mL/min, and SO42- ion was determined by suppressed conductance detection through measuring values of peak area. Detection limit （3S/D） found was 0.05 mg/L. Values of recovery found by standard addition method were in the range from 96.3%- 104.3%.