顺序注射化学发光联用技术测定空气中的SO_2

Determination of sulfur dioxide in air by sequential injection analysis with chemiluminescence detection

基于在酸性溶液中SO32-被Ce4+氧化成SO42-产生很强的化学发光的原理,将顺序注射(SI)进样和化学发光(CL)检测方法联用,以0.012%三乙醇胺作吸收液,成功地测定了空气中的SO2。其浓度与发光信号强度在6.40×10-9～1.28×10-5mol/L范围内呈线性关系。方法的检出限(3σ)为4.80×10-9mol/L,对3.20×10-7mol/L的SO32-溶液9次测定的相对标准偏差为2.9%,方法回收率为98.45～103.6%。分析频率为90样/h。

<Abstrcat>A sensitive, fast sequential injection method for the chemiluminescent determination of trace amounts of sulfur dioxide in air was described. Sulfur dioxide in air was absorbed by triethanolamine, and oxided by Cerium(Ⅳ) to produce intensive chemiluminescence. The CL intensity is proportional to the concentration of sulfite in the range from 6.40×10^(-9) to 1.28×10^(-5) mol/L. The detection limit(C/N=3) is 4.8×10^(-9) mol/L and the relative standard deviation of nine replicate measurements for 3.2×10^(-7) mol/L sulfite is 2.9%. The method has been applied to the determination of sulfur dioxide in air, and the recoveries are 98.45%～103.6%.