【摘要】 <正> 常用测定银的双硫腙法、二乙基二硫代氨基甲酸钠法和二甲氨基苄基若丹宁法,都要经过萃取,手续较烦。Dagnall等曾用邻二氮菲-溴邻苯三酚红测定银,洪水皆等报导了在阴离子表面活性剂存在下用5-Cl-PADMA测定银,然而利用混合表面活性剂存在下光度法测定银尚未见报导。作者曾研究了在阴—非离子表面活性剂混合液中对Ag~+-5-更多还原

【Abstract】 A simple spectrophotometric method for silver has been established by reacting silver（Ⅰ）with 4-（5-chloro-2-pyridylazo）-1, 3-diaminobenzene（5-Cl-PADAB）in the Presence of a mixture of anionic-nonionic surfactants, sodium lauryl sulfate and Peregal O[C₁₈H₃₇O（CH₂CH₂O）_15-20H). The system obeys Beer′s law in the range 0—25μg Ag/25ml. The apparent molar absorptivity is 4.7×10⁴l.mol^-l.cm^-1 at 515 nm. The absorbance is constant over the PH range 8—11. The molar ratio of silver to 5-CI-PADAB is 1: 2. The colour of aqueous solutions is stable for at least 24 hr. With sodium citrate and EDTA-Ca as masking agents, this method is selective for the determination of silver. The method has been applied to ore analysis with satisfactory results.更多还原