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滴定法测定硫脲的方法,首先为及其他一些研究者研究出来。通常按方法使硫脲分解,根据析出的氨的量;或则用硝酸、王水将硫氧化得到SO_4~(-2)离子,然后用一般的方法测定氨,以决定硫脲的含量。可以用过氧化氢得到游离氨,并用滴定分析法测定氨来测定硫脲。但是提到的方法有一个共同的缺点,即使硫脲分解要化费很多时间。不要预先分解硫脲,可在水溶液中进行硫脲的测定,用二硝基汞溶液滴定,以氨铁钒,亚硝基铁氰化钠,二苯卡巴脲,二苯卡巴腙或者β—亚硝基—α萘酚作为指示剂。假如在水溶液中测定,列举的指示剂可以得到很好的结果,但是大多数硫脲在水中很少溶解。在有机
The titrimetric method for the determination of thiourea was first developed by some researchers and others. Thiourea is usually decomposed according to the method according to the amount of ammonia precipitated; or, sulfuric acid is oxidized with nitric acid and aqua regia to obtain SO_4 ~ (-2) ions, and ammonia is determined by a general method to determine the content of thiourea. Free ammonia can be obtained from hydrogen peroxide and thiourea can be determined by titrimetric analysis of ammonia. However, the methods mentioned have the common disadvantage that even if the thiourea decomposes, it takes a lot of time. Do not pre-decomposition of thiourea, thiourea determination in aqueous solution, titration with dinitro mercury solution, vanadium ammine, nitroso, sodium cyanide, diphenylcarbazide, diphenylcarbazone or β- Nitro-alpha naphthol as an indicator. Enumerated indicators give good results if measured in aqueous solution, but most thioureas dissolve less in water. In organic