对硒 -碘化钾 -结晶紫 -聚乙烯醇显色体系进行了较系统的研究。结果表明 ,硒在盐酸介质中可与 I- 3 离子形成三元缔合物 ,其缔合物的最大吸收波长为 560 nm,ε为 2 .31× 1 0 5,硒含量在 0～ 6μg/2 5ml范围内服从比耳定律 ,利用巯基棉分离干扰离子 ,选择性高 ,测定海豚肝脏及茶叶中硒含量与加标回收率 ,结果满意。 The color system of selenium-potassium iodide-crystal violet-polyvinyl alcohol was studied systematically. The results show that selenium can form ternary association with I-3 in hydrochloric acid medium, the maximum absorption wavelength of its association is 560 nm, ε is 2.31 × 105, selenium content is 0-6μg / 25ml range subject to Beer’s law, the use of mercapto-cotton separation of interfering ions, high selectivity, determination of dolphin liver and tea selenium content and spike recovery, the results were satisfactory.