【摘要】 <正> 变色酸双偶氮胂类化合物是光度法测定稀土元素的重要显色剂,如偶氮胂Ⅲ、三溴偶氮胂等。为研究各种取代基对这类显色剂与稀土配合物的影响,将对甲基二溴偶氮胂中的甲基换为甲酰基,合成得偶氮胂DBF,化学命名为2-（2-胂酸基苯偶氮）-7-（2,6二溴-4-甲酰基苯偶氮）-1,8-二羟基萘-3,6-二磺酸。pH 2.2时,偶氮胂与铈组稀土生成蓝色配合物,λ_max为630 nm,ε₆₃₀^La=1.31×10⁵ L·mol^-1·cm^-1。更多还原

【Abstract】 The present paper reports the synthesis of arsenazo DBF, its characteristic, its reaction with rare earths ions and its application to the selective determination of cerium-group in aluminium-alloy. Arsenazo DBF, 2- （2-arsonophenylazo）- 7- （ 2, 6-dibromo- 4- formylphenylazo ）- 1,8-dihydroxynaphthalene-3,6-disulfonic acid reacts with cerium-group rare earths to form blue-green colour complexes in NaAe-HC1 aqueous solution at pH 2.2. The absorptive peak is at 630 nm. The molar absorptivity of La complexe is 1.3×10⁵ L·mol^-1·cm^-1. Beer’s law is obeyed over the concentration range 0～12μg/25mL of La.更多还原