【摘要】 于ｐＨ６７～７６的磷酸盐缓冲介质中，溴化十六烷基三甲铵存在下，Ｐｄ（Ⅱ）与５′＿硝基水杨基荧光酮３０ｍｉｎ内反应完全，生成组成比１∶２的紫红色配合物。λｍａｘ＝５８２ｎｍ，Δλ＝５６ｎｍ，表观ε为１０４×１０５Ｌ·ｍｏｌ－１·ｃｍ－１，配合物至少稳定３６ｈ。测Ｐｄ（Ⅱ）的线性范围在０～０８０ｍｇ／Ｌ。结合丁二酮肟＿氯仿萃取分离，方法可用于试样中微量钯的测定，结果与５＿Ｂｒ＿ＰＡＤＡＢ光度法一致，标准加入回收率为９３２％～１００４％，相对标准偏差为１７％（ｎ＝１０）。更多还原

【Abstract】 In phosphate buffer medium of pH 6.7～7.6, and in the presence of cetyltrimethylammonium bromide（CTMAB）, palladium（Ⅱ） forms a 1∶2 soluble complex with 2,6,7_trihydroxy_{92′hydroxy5′nitro}phenylfluorone₃. The complex has a maximum absorption at 582 nm with contrast Δ λ =56 nm, and the apparent molar absorptivity is 1.04×10 5 L·mol -1 ·cm -1 . The chromogenic reaction is complete in 30 min and the color is stable for at least 36 h. Beer′s law is obeyed in the range of 0～0.80 mg/L for palladium. The effect of other metal ions on the determination of Pd has also been investigated. The method has been applied to the determination of palladium in an alloy after separating the interfering ions from the sample by extraction with dimethyl glyoxime and chloroform in acidic medium. The recovery is 93.2%～100.4% with precision of 1.7% RSD（ n =10）. The result is in good agreement with that provided by 5_Br_PADAB spectrophotometry.更多还原