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2-(3,5-二溴-2-吡啶偶氮)-5-二乙氨基苯酚(简称3,5-diBr-DEPAP)测定铬、钒、镓、银已有报道。本文研究了在乳化剂OP存在下,以三乙醇胺-盐酸缓冲液控制pH7.8-9.6范围内,3,5-diBr-DEPAP与铜、锌的显色反应。结果表明,铜和锌与显色剂同时生成最大吸收波长位于575nm处的1:3紫色配合物,表观摩尔吸光系数分别为9.24×10~4和1.22×10~5。铜、锌含量在0-9μg/25mL范围内服从比尔定律。铜、锌各为5μg/25mL时测定误差小于5%,在未加掩蔽剂时,以下共存物质允许量(以μg计)为:Ag~+(45),Hg~(2+)、Bi~(3-)(4.0)、Cd~(2+)、Cr~(3+)(0.8),Pb~(2+)、Ti~(4+)(9.0),Ni~(2+)、Sn~(4+)、
Chromium, vanadium, gallium and silver have been reported for the determination of 2- (3,5-dibromo-2-pyridylazo) -5-diethylaminophenol (3,5-diBr-DEPAP) In this paper, the color reaction of 3,5-diBr-DEPAP with copper and zinc was studied in the presence of emulsifier OP with triethanolamine-hydrochloric acid buffer in the range of pH7.8-9.6. The results showed that the copper and zinc complexes with 1: 3 purple color with the maximum absorption wavelength at 575 nm were obtained. The apparent molar absorptivities were 9.24 × 10 ~ 4 and 1.22 × 10 ~ 5, respectively. Beer’s law is obeyed in the range of 0-9μg / 25mL for copper and zinc. The allowable amount (in μg) of the following coexisting substances in the absence of masking agent is: Ag ~ + (45), Hg ~ (2 +), Bi ~ (2 +), Cr (3 +) (0.8), Pb ~ (2 +), Ti ~ (4 +) (9.0), Ni ~ (2 +), Sn ~ (4+),