Method for determining bismuth tungstate impurities synthesized by hydrothermal method and method for purifying bismuth tungstate

The invention discloses a method for determining bismuth tungstate impurities synthesized by a hydrothermal method and a method for purifying bismuth tungstate. The bismuth tungstate synthesized by the hydrothermal method is dispersed in a nitric acid solution, soaking and centrifuging are carried out, and a supernatant is taken to dilute to a proper multiple. The bismuth tungstate is dispersed ina sodium hydroxide solution, the solution is heated to boil, the cooling and centrifuging are carried out, a supernatant is taken, the diluting is carried out, and trace concentrated nitric acid is added to make the solution weakly acidic. The bismuth element concentration and the tungsten element concentration are measured by using an inductively coupled plasma mass spectrometer. The weights ofcorresponding impurities are calculated so as to obtain the content of the impurities in an original product. The purified bismuth tungstate is separated from the solution by using a Buchner funnel, the washing and drying are