论文部分内容阅读
铊与钼生成杂多酸,铊中硅的测定通常要用异丙醚在氢溴酸介质中萃弃铊。我们采取加大钼酸铵用量(0.5克铊,用钼酸铵不小于1克,1克铊不小于2克)的办法,直接萃取测定硅,方法简便、快速.对国标铊中硅的分析,结果与标准值一致. 分析方法:称取铊0.5～1克于250毫升聚四氟乙烯杯中,加2毫升(1+1)硝酸低温溶解,滴加4滴饱和尿素,摇匀.加水10毫升,氢氟酸2滴,摇匀,置30～40℃保温1小时。加饱和硼酸10.0毫升,摇匀,放置半小时,加2%亚硫酸钠溶液2毫升,摇匀,加20%钼酸铵(需提纯)6.0毫升(1克铊则加12.0毫升),放置15分钟,加(1+2)硫酸20.0毫升,摇动
Thallium and molybdenum generate heteropolyacids, the determination of silicon in thallium is usually extracted with isopropyl ether in hydrobromic acid medium thallium. We take to increase the amount of ammonium molybdate (0.5 grams of thallium, ammonium molybdate is not less than 1 gram, 1 gram of thallium is not less than 2 grams), the direct extraction and determination of silicon, the method is simple and fast analysis of the national standard thallium , The results are consistent with the standard value. Analysis: Weigh 0.5 to 1 gram of thallium in 250 ml Teflon cup, add 2 ml (1 + 1) of nitric acid dissolved in low temperature, dropping 4 drops of saturated urea, shake. 10 ml, 2 drops of hydrofluoric acid, shake, set 30 ~ 40 ℃ incubated for 1 hour. Add saturated boric acid 10.0 ml, shake, place for half an hour, add 2% sodium sulfite solution 2 ml, shake, add 20% ammonium molybdate (to be purified) 6.0 ml (1 g thallium plus 12.0 ml), place for 15 minutes, Add (1 + 2) sulfuric acid 20.0 ml, shake