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纯钼和三氧化钼中微量钨的测定是分析上较困难的问题。本文根据Affcprung和Murphy等提出在8～9当量盐酸溶液中钨(Ⅵ)被氯化亚锡还原成五价与四苯砷氯盐酸盐和硫氰酸盐形成黄色不溶性的硫氰基钨酸四苯砷离子对(C_6H_5)_4As~+-W(OH)_2-(CNS)_4~-三元络合物的反应和汪炳武提出用盐酸,氯化亚锡反洗萃取后有机相的办法消除大量钼的干扰可能性基础上,着重研究了用四苯砷氯盐酸盐——硫氰酸盐萃取比色测定微量钨的有关条件,并用于纯钼,三氧化钼中微量钨的测定。实验表明,用氯化亚锡还原钨最适宜的酸度为8～9当量盐酸,并采取增加氯化亚锡用量和反洗萃取后有机相的方法消除大量钼(1克)的
Determination of trace amounts of tungsten in pure molybdenum and molybdenum trioxide is a more difficult analytical problem. According to Affcprung and Murphy et al., It is proposed that the reduction of tungsten (Ⅵ) from stannous chloride to pentavalent and tetraphenyl arsenic chlorides and thiocyanates to form yellow insoluble thiocyanato-tungstic acid in 8 to 9 equivalents of hydrochloric acid The reaction of tetraphenylarsine ion pair (C_6H_5) _4As ~ + -W (OH) _2- (CNS) _4 ~ ternary complex and Wang Bingwu proposed to eliminate the organic phase by hydrochloric acid and stannous chloride On the basis of the possibility of interference with a large amount of molybdenum, the conditions for the determination of trace tungsten by colorimetric extraction with tetraphenyl arsenic chloride and thiocyanate were studied emphatically. The determination of trace tungsten in pure molybdenum and molybdenum trioxide was also studied. Experiments show that the most suitable acidity for the reduction of tungsten with stannous chloride is 8 to 9 equivalents of hydrochloric acid. A large amount of molybdenum (1 g) is eliminated by increasing the amount of stannous chloride and the organic phase after backwashing