二苯碳酰二肼光度法测定超基性岩石中三氧化二铬的改进
Improvement in the Determination of Chromic Oxide in Ultramafic Rocks by Diphenylcarbazide Spectrophotometry
-
摘要: 二苯碳酰二肼光度法是测定微量Cr(Ⅵ)的行业标准方法,以硫酸作为显色介质,酸度要求严格,显色稳定时间短,体系显色后需在10 min~1 h测定完毕,灵敏度较差。本文对标准方法进行改进,将显色介质由硫酸改为磷酸。结果表明,在H3PO4介质中显色剂与Cr(Ⅵ)反应生成的络合物可稳定3 h,方法相对标准偏差(RSD)≤5.25%,加标回收率为99.2%~102.0%,检出限由标准方法的13.6 μg/g降至3.8 μg/g。建立的方法用于超基性岩标准物质分析,相比于标准方法,稳定性、精密度和准确性均有提高。Abstract: Diphenylcarbazide Spectrophotometry is a standard method to measure trace Cr (Ⅵ). However, using H2SO4 as the chromogenic medium has limitations such as a strict sulfuric acid concentration, short stability time of 10-60 min and poor sensitivity. An improvement was made to the diphenylcarbazide spectrophotometric method by replacing sulfuric acid with phosphoric acid as the chromogenic medium. Results indicate that the reaction is stable for 3 h in the phosphoric medium, and the detection limit is reduced from 13.6 μg/g to 3.8 μg/g with a recovery factor of 99.2%-102.0% and RSD≤5.25%. Compared with the routine method, the improved method, when applied to ultramafic rock standard materials demonstrates higher stabilization, precision and accuracy.
-
Keywords:
- phosphate /
- diphenylcarbazide /
- spectrophotometry /
- ultrabasic
-
-
岩石矿物分析编写组.岩石矿物分析(第一分册)[M].北京:地质出版社,1974:95. 胡德文,马成义,陈甲斌.我国铬铁矿供需状况及其可持续供应对策探讨[J].矿产保护与利用,2004(3):9-11. 王成,孙宝生,张建,唐兰兰.超基性岩地球化学特征[J].西部探矿工程,2006(5):104-106. 王虹,冯宇新,苏明跃,王晶.火焰原子吸收光谱法测定红土镍矿中铬[J].冶金分析,2007,27(9):54-56. 王世武,魏春艳,董玉兰,张俐.火焰原子吸收光谱法测定铁矿石中Zn、Co、Ni、Pb、Cr含量[J].包钢科技,2003,29(4):84-86. 郭晓红,刘桂玲,侯南芬,张广隆.酸溶二苯碳酰二肼分光光度法测定水系沉积物样品中微量铬[J].山东国土资源,2004,20(4):57-59. 胡郁,苏丹,陈思成.ICP-AES法测定超基性岩石样品中的磷、锡、钒、铬、锰[J].黄金,2005,26(7):50-51. 金献忠,陈建国,梁帆,郑琳,张建波,应海松,林力.碱熔融-ICP-AES法对锰矿石中主量、次量与痕量元素的同时测定[J].分析测试学报,2009,28(2):150-156. 张家相,吴丽萍,喻娟. ICP-AES同时测定矿石中Cr、Ni含量[J].冶金标准化与质量,2007,44(3):12-14. 安裕敏.土壤铬的测定方法探讨[J].微量元素与健康研究,2007,24(5):45-46. 张晶.空气-乙炔火焰原子吸收法测定铬时铁的干扰及消除[J].云南冶金,1992(3):50-54. 王雪莹.空气-乙炔火焰原子吸收法测定铬时铁的干扰及抑制方法[J].山东冶金,1997,19(3):43-46.
计量
- 文章访问数: 1387
- HTML全文浏览量: 0
- PDF下载量: 1084
下载:
京公网安备 11010202008159号