摘要：

采用FIA-TPTZ分光光度法分析系统测定电厂水汽中痕量铁，考察了测试液pH对测定结果准确性的影响。结果表明，配制标准溶液所用铁贮备液的盐酸浓度和水样经消解处理后的pH对测定结果均有较大影响。配制100 μg/L以下的Fe³⁺铁标液，铁贮备液HCl浓度宜控制在4.0~5.0 mol/L；配制100 μg/L以上的Fe³⁺标液，铁贮备液HCl浓度宜控制在1.0~2.0 mol/L。水汽样品经消解处理后先将Fe³⁺还原成Fe²⁺，再行调整测试液pH，可提高实际应用中的可操作性和方法的测定准确性。

关键词: 电厂水汽, 痕量铁, Fe²⁺-TPTZ分光光度法, 测试液pH

Abstract:

The FIA-TPTZ spectrophotometry was used to determine the trace iron in water-steam at power plants. The influence of the pH of water samples on the measurement accuracy was studied. The result showed that both of the concentration of hydrochloric acid in iron standard stock solution and the pH of the digested sample had serious impacts on the determination results. The concentration of hydrochloric acid in iron standard stock solution was suitable to be controlled in the range of 4.0-5.0 mol/L, when the concentration of iron standard solution was lower than 100 μg/L. While the concentration of hydrochloric acid in iron standard stock solution was suitable to be controlled in the range of 1.0-2.0 mol/L, when the concentration of iron standard solution was higher than 100 μg/L. The operability and accuracy in actual application could be increased by adjusting the pH of the test liquid after Fe³⁺ in the digested sample was reduced to Fe²⁺.

Key words: water-steam at power plant, trace iron, Fe²⁺-TPTZ spectrophotometry, pH of test solution

中图分类号: 

• O657.3