摘要
本文研究了1-(5-溴-2-吡啶偶氮)-2-萘酚-6-磺酸(5-Br-PAN-S)与铜(Ⅱ)的显色反应。实验表明,铜(Ⅱ)与5-Br-PAN-S形成的络合物的组成比随pH值的变化而变化,在pH2.0~6.0,形成1:1络合物,最大吸收峰为558nm,表观摩尔吸光系数为2.30×104Lmol-1cm-1,在pH9.0形成1:2络合物,其最大吸收峰为551nm,表观摩尔吸光系数为3.92×104Lmol-1cm-1,并求得铜(Ⅱ)与5-Br-PAN-S络合物的lgβ1=14.23,铜量在0~35μg/25ml,(pH2.0)范围内服从比耳定律。用本法测定了柑桔根、叶中铜的含量,结果满意。
Color reaction of copper with 1- (5-bromo-2-pyridylazo)-2-naphthol acid (5-Br- PAN-S) has been studied. The molar ratio of copper(pH2~6) with 5-Br-PAN-S is 1: 1, λmax= 558nm. The apparent molar absorptivity of this chelate is 2. 30×104Lmol-1 cm -1 At pH9. 0, the molar ratio of copper with 5-Br-PAN-S is 1: 2, λmax= 551nm,and its apparent molar absorptivity is 3. 92× 104 Lmol -1cm-1.Bear's law is observed in the range of 0~ 35μg/25mL, (pH = 2 ). This method has been applied to the determination of trace copper in the roots and leaves of orange trees with satisfactory results.
出处
《浙江师大学报(自然科学版)》
1997年第3期58-61,共4页
Journal of Zhejiang Normal University(Natoral Sciences)
关键词
铜
溴
吡啶偶氮
萘酚
磺酸
分光光度法
copper
1-(5-bromo-2-pyridylazo)-2-naphthol-6-sulphonic acid
spectrophotometry