The sample was decomposed using a kind of mixed flux consisting of Na2CO3 and H3BO3 in the crucible of which graphite powder was put in the botton.

• 采用无水碳酸钠-硼酸混合熔剂在石墨碳粉垫底坩埚中高温熔融分解试样，使试样中大部分铬形成难溶于酸的硼化铬或破硼化铬而与磷、锰分离。