Abstract：Cobalt-chromium ceramic alloy is one of mostly used in dentistry. So far, there is no related test standard, and there are only few reports on the related detection methods at home and abroad. Chromium is the main composition in cobalt-chromium ceramic alloy. It urgently need to develop the testing methods and provide important guidance for its production, use and trading. In experiments, the sample was treated by microwave digestion using 10mL of hydrochloric acid, 3mL of nitric acid and 2mL of hydrofluoric acid. The chromium (III) in sample solution was oxidized to chromium (VI) by ammonium persulfate in medium of sulfuric acid-phosphoric acid mixture using silver nitrate as catalyst. Manganese sulfate solution was added. It could be considered that chromium had been completely oxidized when Mn2+ was oxidized until purple red appeared. Meanwhile, Mn2+ was oxidized to permanganate. Little sodium chloride solution was added to destroy the permanganate by boiling. N-phenylanthranilic acid solution was added as the indicator for the titration using standard titration solution of ammonium ferrous sulfate. The determination of chromium content in cobalt-chromium ceramic alloy was realized. According to the content range of each element in sample, the interference tests of coexisting elements were conducted using 2-4 times of maximum content. The results showed that the recoveries of chromium were between 98% and 100% under experimental conditions, indicating that the coexisting elements in sample had no interference with the determination of chromium. The experimental method was applied for the determination of chromium in actual sample of cobalt-chromium ceramic alloy. The relative standard deviations (RSD, n=11) were 0.49% and 0.50%, and the recoveries were between 99% and 101%. According to the composition range of elements in sample, the simulated samples of cobalt-chromium ceramic alloy were synthesized and determined using the experimental method. The found results of chromium content were consistent with the theoretical values.
战德松,王强,李柘.金属烤瓷合金的研究进展[J].中国实用口腔科杂志(Chinese Journal of Practical Stomatology),2008,1(2):115-119.
[2]
麦丽碧,许洁瑜,陈小兰,等.碘量法测定钴铬烤瓷合金中的钴[J].材料研究与应用,2016,10(3):229-232.MAI Li-bi,XU Jie-yu,CHEN Xiao-lan,et al.Determination of cobalt in Co-Cr ceramic alloy by iodometry[J].Materials Research and Application,2016,10(3):229-232.
[3]
梁云生,杨毅,毛文剑.硫酸亚铁铵滴定法快速测定铬铁矿中铬[J].岩矿测试,2007,26(1):73-74.LIANG Yun-sheng,YANG Yi,MAO Wen-jian.Rapid determination of chromium in chromite samples by titrimetry with ammonium ferrous sulfate[J].Rock and Mineral Analysis,2007,26(1):73-74.
[4]
吕瑞云,刘心怡.硫酸亚铁铵滴定法快速测定铬铁中铬[J].理化检验:化学分册(Physical Testing and Chemical Analysis Part B:Chemical Analysis),2010,46(2):192-194.
[5]
杨林.碳化钨掺钒掺铬粉末中铬的测定[J].中国钨业,2012,27(2):47-49.YANG Lin.Chromium amount measurement in the tungsten carbide powder doped with vanadium and chromium[J].China Tungsten Industry,2012,27(2):47-49.
陈金身,闫国进.铜基金刚石工具中铬的快速测定[J].超硬材料工程.2006,18(1):8-9.CHEN Jin-shen,YAN Guo-jin.Rapid determination of chromium in Cu-based diamond tools[J].Superhard Material Engineering,2006,18(1):8-9.
[9]
罗道成,刘俊峰.高氯酸氧化硫酸亚铁铵滴定法测定钢铁中铬的改进[J].冶金分析,2005,25(2):78-80.LUO Dao-cheng,LIU Jun-feng.Improvement for titrimetric determination of chromium in steel based on ferrous ammonium sulfate oxidized by perchloric acid[J].Metallurgical Analysis,2005,25(2):78-80.
[10]
王俊秀,付士刚.硫酸亚铁铵滴定法测定铬青铜中的铬[J].山东冶金,2011,33(1):73-74.WANG Jun-xiu,FU Shi-gang.Determination of chromium in chromium bronze by ammonium ferrous sulfate titrimetric method[J].Shandong Metallurgy,2011,33(1):73-74.
[11]
周金芝,李佗.硫酸亚铁铵滴定法连续测定铝钒锡铬合金中钒和铬[J].冶金分析,2015,35(6):70-73.ZHOU Jin-zhi,LI Tuo.Continuous determination of vanadium and chromium in aluminum vanadium tin chromium alloy by ammonium ferrous sulfate titrimetry[J].Metallurgical Analysis,2015,35(6):70-73.
