阀切换离子色谱法测定电厂烟气异丙醇吸收液中三氧化硫的含量

建立了一种阀切换离子色谱法检测烟气中SO_3的方法,通过检测异丙醇(80%)前处理过的样品中SO_4~(2-)含量来实现对SO_3含量的检测。采用异丙醇(80%)吸收液将样品中的SO_3转化为SO_4~(2-),利用阀切换的在线预处理方法除去高浓度异丙醇对SO_4~(2-)测定所造成的影响。结果表明,在0.5～10.0mg/L线性范围内,其相关系数R~2=0.999 3,相对标准偏差为2.7%(n=6),检出限为0.7×10~(-2) mg/L,所得样品的加标回收率为95.0%～105%。方法可用于燃煤电厂烟气中SO_3含量的检测。

Determination of sulfur trioxide in isopropanol absorbent of power plant flue gas by valve switching ion chromatography

A new method for the determination of SO3 in flue gas by ion chromatography valve switching system was established. The content of SO3 was detected by detecting content of SO4^2- in 80% isopropanol pre-treated samples. The SO3 in the sample was converted into SO4^2- by 80% isopropanol absorption solution, and the influence of high concentration of isopropanol on the determination of SO4^2- was removed by the online pretreatment method of valve switching. The results showed that in the linear range of 0.5-10.0 mg/L, the correlation coefficient R² was 0.9993, the relative standard deviation was 2.67 (n=6), the detection limit was 0.7×10^-2 mg/L, and the spiked recovery of the samples was 95.0%-104.7%.This method can be used for the determination of SO3 content in flue gas of coal-fired power plants.