Determination Of Sulfur Dioxide In Air And Iodine In Food By Sequential Injection Analysis With Chemiluminescence Detection

In this dissertation, the sequential injection method combined with chemiluminescence detecting technique was applied for the determination of sulfur dioxide in air and iodine in food samples, and the whole operation procedure was controlled by computer and satisfactory results were obtained.The first section of the dissertation concerned the review on the progress of analytical methods for the determination of sulfur dioxide analysis in recent years. The methods such as spectrophotometry, iodometric method, chromatography, potentiometry and molecular luminescence analysis were introduced and their analytical performance was evaluated.The second section of the dissertation described sequential injection with chemiluminescence to detect trace amounts of sulfur dioxide in air. Sulfur dioxide in air was absorbed by triethanolamine (TEA), and oxidized by Cerium(IV), produced sensitive chemiluminescence. A univariate approach was adopted for the optimization of experimental parameter. The CL intensity is proportional to the concentration of sulfite in the range from 2.4×10^-81.3×l0^-5mol/L. The detection limit(3σ) is 4.9×10^-9 mol/L and the relative standard deviation for nine repeated measurements for 3.2×10^-7 mol/L sulfite is 2.9%. The method was applied to the determination of sulfur dioxide in air and the recoveries is 98.5¹03.6%.In the third section, a simple, fast sequential injection system with chemiluminescence detection for the determination of iodine in food was presented, based on iodide ion is oxidized by potassium permanganate with...