用苯芴酮比色法测定锡受多种元素的干扰,其中尤以钨、钼、钛等元素的干扰更大。我们以铍为载体,用氨水沉淀锡和大量钼分离,然后在9N硫酸-0.5M碘化钾介质中,用甲苯(或苯)萃取SnI4,进一步与残留钼和其它干扰离子分离,然后作比色测定。进行了含锡量为0.002—0.025％钼丝中锡的测定,所得结果的重现性较好。于1克钼中,加入0.02—0.4毫克锡的回收率在90—96％之间。方法的灵敏度为1微克Sn/25毫升。 (一)分析步骤称取0.5-1.0克试样,置于400毫升烧杯中,加10-30毫升王水,小心加热溶解并煮沸驱尽二氧化氮。取下,加入10毫升硫酸铍溶液(1毫克/毫升,此溶液每升中含硫酸10毫升)和5毫升10％EDTA溶液,用水稀释至约150毫升,加入15毫升浓氨水,加热至微沸后,加入50％硝酸铵15毫 Benzofluorenone colorimetric determination of tin by a variety of elements of interference, especially in tungsten, molybdenum, titanium and other elements of greater interference. We use beryllium as support, precipitated with ammonia water and a large amount of molybdenum separation, and then 9N sulfuric acid - 0.5M potassium iodide medium, extracted with toluene (or benzene) SnI4, and further residual Mo and other interfering ions, and then for colorimetric determination . The determination of tin in molybdenum wire with tin content of 0.002-0.025% was carried out, and the reproducibility of the obtained results was good. In 1 gram of molybdenum, the recovery of 0.02-0.4 milligram tin is between 90-96%. The sensitivity of the method is 1 μg Sn / 25 ml. (A) Analysis step Weigh 0.5-1.0 g sample, placed in a 400 ml beaker, add 10-30 ml of aqua regia, carefully heated to dissolve and boil out of nitrogen dioxide. Remove and add 10ml beryllium sulfate solution (1mg / ml, this solution contains 10ml of sulfuric acid per liter) and 5ml of 10% EDTA solution, dilute with water to about 150ml, add 15ml of concentrated aqueous ammonia and heat to slightly boil After adding 50% ammonium nitrate 15 milliliters