硅铁中铬量测定

Determination of Chromium Content in Ferrosilicon

本法采用硝酸、氰氟酸溶样,加入硫磷混酸加热冒烟驱尽氟离子及氮化物,用硝酸银作催化剂,过硫酸铵为氧化剂,将低价铬离子氧化至高价铬离子,利用二苯偕肼与铬离子形成稳定紫色络合物,以550 nm为测定波长,测定出铬的含量。测定结果的相对标准偏差(n=7)均小于1%。方法简便、快速。

In this method, sample is dissolved by nitrate and hydrofluoric acid, then add parathion mixed acid, heat sample to smoke to flood fluorine ion and nitrides. Silver nitrate as the catalyst and ammonium persulfate as the oxidant, low chromium ion is oxidized to high. Chromium ion forms a stable purple complex with diphenylcarbazide hydrazine, so 550 nm for measuring wavelength, Chromium content is determined. The relative standard deviation of results （n = 7） was less than 1%. The method is simple and rapid.