光度法快速测定不锈钢中的铬、镍、钼、钛、锰

试样用等体积硝酸和盐酸混合酸溶解,用高氯酸将Cr(Ⅲ)氧化为Cr(Ⅵ),用定量Fe(Ⅱ)将Cr(Ⅵ)定量还原为Cr(Ⅲ),用铬酸"剩余光度法"测定铬,丁二酮肟光度法测定镍,硫氰酸盐光度法测定钼,变色酸(1,8-二羟基萘-3,6-二磺酸)光度法测定钛,高锰酸光度法测定锰。测定结果与标准值基本一致,铬、镍、钼、钛、锰测定结果的相对标准偏差分别为0.2%、0.3%、1.5%、2.0%、2.0%。

RAPID DETERMINATION OF Cr,Ni,MO,Ti,Mn IN STAINLESS STEEL BY SPECTROPHOTOMETRY

The samples were dissolved with the admixture acid of hydrochloric acid and nitric acid （ equal volume） , and then perchloric acid was added to oxidize Cr（ Ⅲ ） into Cr（ Ⅵ）. After the solution was cooled and diluted, quantitative Fe（ Ⅱ ） was added to reduce Cr（ Ⅵ ） into Cr（ Ⅲ ） quantitatively. The solution was volume - determined and then chrome in the samples was detected by the surplus quantity speetrophotomctry of chromic acid. Nickel was determined by the dimethylglyoxime speetrophotometry. Molybdenum was determined by the thiocyanate spectrophotometry. Titanium was determined by the chromotropic acid spectrophotometry and manganese was determined by the permanganic acid speetrophotometry. The detection results by the method were consistent with the standard values. The relative standard deviations of Cr, Ni, Mo, Ti, Mn detection results were 0.2% , 0.3% , 1.5% , 2.0% , 2.0% respectively.