中文摘要：

合成了新试剂5-（5-磺酸-2-吡啶偶氮）-2,4-二氨基甲苯（5-SO_3H-PADAT）,用红外光谱和核磁共振波谱对其结构进行了表征,研究了该试剂与钯（Ⅱ）的显色反应并建立了双波长叠加光度法测定钯（Ⅱ）的方法。结果表明：在0.06~1.8mol/L H_2SO_4介质中,该试剂与钯（Ⅱ）形成稳定的络合物,该络合物有两个吸收峰,分别位于580nm和543nm处;钯（Ⅱ）质量浓度在0.04~1.2μg/mL之间符合比尔定律,表观摩尔吸光系数为1.49×10~5 L·mol~（-1）·cm~（-1）。方法用于钯分子筛和钯炭催化剂中钯的测定,所得结果与西北有色金属研究院西安凯立化工有限公司提供的参考值相符,相对标准偏差（RSD,n=6）分别为1.3%和2.6%,回收率分别为94%和108%。

英文摘要：

A new reagent of 5-（5-sulfonic-2-pyridyazo）-2,4-diaminotoluene（5-SO_3H-PADAT）was synthesized.Its structure was characterized by infrared spectroscopy and nuclear magnetic resonance spectroscopy.The coloring reaction between this reagent and palladium（Ⅱ） was investigated and the determination method of palladium（Ⅱ） by dual wavelength overlapping spectrophotometry was established.The results showed that 5-SO_3H-PADAT could form stable complex with palladium（Ⅱ）in 0.06-1.8mol/L H_2SO_4 medium.This complex had two absorption peaks,which were located at 580 nm and 543 nm,respectively.Beer＇s law was obeyed for palladium（Ⅱ） with mass concentration in range of 0.04-1.2μg/mL.The apparent molar absorptivity was 1.49×10~5 L·mol~（-1）·cm~（-1）.The proposed method was applied to the determination of palladium in palladium molecular sieve and palladium-carbon catalyst.The results were consistent with the reference values provided by Xi＇an Kaili Chemical Co.,Ltd.of Northwest Institute for Nonferrous Metal Research（NIN）.The relative standard deviations（RSD,n=6）were 1.3% and 2.6%,respectively.The recoveries were 94% and 108%,respectively.