|
|
Murexide Spectrophotometric Determination of Magnesium Oxide in Dehydration Products of Bischofite from Hydrated Double Salt Method |
HU Hu-sheng,YANG Ming-de,WU Yu-long |
Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 102201, China |
|
|
Abstract For determination of MgO in dehydration products of hydrated double salt (C6H5NH2·HCl·MgCl2·6H2O), that direct measurement of the MgO in the water-insolvable residue of dehydration product samples was substituted for the conventional indirect method yielded more accurate results. The water-insolvable residue was resolved by boiling diluted H2SO4 solution and the microgram amount magnesium in the solution was measured by spectrophotometry, using murexide as a color reagent. The effects such as pH of solution, complex ratios of magnesium to murexide, dosages of chromogenic reagent, reaction time on the absorbances of coloured solutions, and the tolerance limits of some interfering ions such as C6H5NH2·H+、Fe3+、Zn2+、Ba2+、Ca2+、Ni2+、Co2+ and their masking reagents are investigated. The calibration curve is established under completely deduction of the absorbance of remnant colour reagent according to the correction spectrophotometric theory. In the concentration range of 0~2 mmol/L of Mg2+, the calibration curve is linear and molar absorptivity 2.45×102 L/(mol·cm). The experimental results show that this method can give high precisions and accuracies (recoveries of standard addition were close to 100%), therefore it is suitable for analysis of the MgO in dehydration products.
|
|
|
|
|
[1]Sugimoto K, Dinnebier R E, Hanson J C. Structures of three dehydration products of bischofite from in situ synchrotron powder diffraction data (MgCl2·nH2O; n=1, 2, 4)[J]. Acta Crystallogr B: Struct Sci, 2007, 63(2):235-242.
[2]Kashani-Nejad S, Harris R. Characterization of MgOHCl/MgO mixtures with infrared spectroscopy (IR)[C]//Conference on Magnesium Technology,Charlotte NC,2004.
[3]Huang Q Z, Lu G M, Wang J, et al. Thermal decomposition mechanisms of MgCl2·6H2O and MgCl2·H2O[J]. J Anal Appl Pyrolysis, 2011, 91( 1):159-164.
[4]胡湖生,杨明德,吴玉龙. 水氯镁石复盐法脱水工艺[J]. 有色金属(冶炼部分), 2011,(7):17-21,38.
[5]白钰,欧阳健明, 白燕,等.火焰原子吸收光谱法同时测定尿中钙镁[J].光谱学与光谱分析, 2004,24( 8):1016-1019.
[6]GB/T 1513—2006 矿石钙和镁含量的测定火焰原子吸收光谱法[S].
[7]何建忠,吴胜,邵玉兰. 火焰原子吸收光谱测定水质中钙、镁的方法改进[J].中国卫生检验杂志, 2008,8(9):1903-1904.
[8]孙莹莹,石榴花,孔可可. 火焰原子吸收光谱法测定铝合金中镁[J].现代化工, 2011,31(S1):432-433.
[9]陈郁,马香娟. 偶氮氯膦I分光光度法测定铝合金中髙含量镁[J].中国计量学院学报, 2002,13(4):311-314.
[10]周正义, 印天寿. 二甲酚橙光度法快速测定植株钙、镁[J]. 安徽农业技术学院学报, 1994,8(3):44-52.
[11]吕俐宾. 酸性铬兰K分光光度法测定镁[J].贵州农业科学, 2001,29(5):19-20. [12]Gómez E, Estela J M, Cerdà V. Simultaneous spectrophotometric determination of calcium and magnesium in water[J]. Anal Chim Acta, 1991, 249:513-518.
[13]Tesfaldet Z O, Staden J F V, Stefan R I. Spectrophotometric determination of magnesium in pharmaceutical preparations by cost-effective sequential injection analysis[J].Talanta, 2004,64(15):981-988.
[14]Idriss K A, Sedaira H, Ahmed H M. An insight into the solution equilibria of magnesium(II) with purpurin and spectrophotometric determination of magnesium[J]. Talanta, 2001,54(2):369-375.
[15]Ma H M, Huang Y X, Liang S C. PA. FPNS: its synthesis and use in spectrophotometric determination of magnesium[J]. Talanta, 1996,43(1): 21-26.
[16]Idriss K A,Sedaira H,Ahmed S S. Determination of strontium and simultaneous determination of strontium oxide, magnesium oxide and calcium oxide content of Portland cement by derivative ratio spectrophotometry[J]. Talanta,2009,78(1):81-87.
[17]Benamor M,Aguerssif N.Simultaneous determination of calcium and magnesium by derivative spectrophotometry in pharmaceutical products[J]. Spectrochim Acta Part A, 2008, 69(2):676-681.
[18]章鹏飞,郜洪文. β修正一紫脲酸铵光度法测定铜[J].冶金分析,1995,15(5):28-31. |
|
|
|