学术
摘 要:
基于在pH 10.0的氨水-氯化铵介质中,显色剂偶氮氯膦Ⅲ与镁发生褪色反应,建立了测定铝合金中镁含量的褪色光度分析方法。讨论了吸收光谱、酸度、试剂用量、干扰离子等因素的影响,确定了反应的最佳条件。在25 mL的显色溶液中,镁量在0～16μg范围内工作曲线呈线性关系。在三乙醇胺、邻菲罗啉和EGTA-pb盐的掩蔽剂存在下,可允许大量铝、铁和一定量锰、铜存在,铝合金中其他共存元素对测定均没有干扰。因此,本法不经分离可直接用于铝合金中镁的测定,其相对标准偏差（n=5）在1.4%～2.1%之间。[著者文摘]
文章出处:
《冶金分析》-2008年28卷2期 -72-74页
分 类 号:
文献标识码:
A
文章编号:
1000-7571（2008）02-0072-03
Discoloring spectrophotometric determination of magnesium in aluminium alloys with chlorophosphonazo Ⅲ
ZHONG Guo-xiu, YANG Hao-yi, HUANG Qing-hua （1. Hubei Research ＆ Designing Institute of Mechanical Electronic Engineering, Wuhan 430070,China;2. Hubei Research ＆ Designing Institute of Building Material, Wuhan 430071 ,China）
Abstract:
Based on the discoloring reaction between magnesium and chlorophosphonazo Ⅲ （CPA-Ⅲ） in pH 10. 0 NH3·H2O-NH4Cl medium, a discoloring spectrophotometry for the determination of magnesium in aluminium alloy is established. The effects of the factors such as absorption spectra,acidity, concentrations of reagent,influence of coexisting ions on the reaction are discussed, and the reaction conditions are optimized. The calibration curve is linear in the range of 0-16 μg/25 ml for magnesium. Large amounts of aluminium, iron and certain amounts of manganese, copper can be tolerated in the presence of the masking reagent, like triethanolamine, phenanthroline and EGTA-pb salt. Other coexistent elements in aluminium alloy do not interfere in the determination. The proposed method can be applied to the determination of magnesium in aluminium alloys, with the RSD（n=5） between 1.4% and 2.1%.[著者文摘]
Key words:
chlorophosphonazo Ⅲ; magnesium; discoloring spectrophotometry; aluminium alloy
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