【摘要】 本文提出了一个用气体扩散膜来消除干扰的流动注射光度分析法来测定水样中微量的S^2-。该法的检出限为0.25μg/ml S^2-,工作曲线的线性范围为0.25～25μg/ml S^2-,对15μg/ml S^2-样品10次测定的相对标准偏差<1％,1h能测定20个样品。用本法测定了几种水样中的S^2-含量,回收率达96％～102％。更多还原

【Abstract】 A new flow injection analysis-spectrophotometric method using a gas diffusion membrane which can eliminate interferences for determining microamounts of S^2- in water samples is proposed. Hydrogen sulphide formed in H₂SO₄ carrier（C） diffuses through the Teflon membrane to the reagent（R） containing iron （Ⅲ）-1, 10-phenan hroline-acetate buffer and reduces iron（Ⅲ） to iron（Ⅱ）. Iron（Ⅱ） reacts with 1, 10-phenanthroline to form a very deep orange-red complex which is determined by spectrophotometry. The color intensity is proportional to the concentration of iron（Ⅱ） resulting from the reduction of iron（Ⅲ） by S^2-. The above observation suggests that it may be used for the determination of mieroamounts of S^2-. The detection limit is 0.25μg/ml for S^2-, the linear range of calibration graphs is 0.25～5μg/ml for S^2-, the relative standard deviation（n=10） for a 15μg/ml S^2- is less than 1%, and 20 samples/h can be analyzed. The method has been used to determine mieroamounts of S^2- in water with satisfactory results and the recovery is 96%～102%.更多还原