2-(2-喹啉偶氮)-1,5-二氨基苯固相萃取光度法测定痕量钯

Solid-Phase Extraction-Photometric Determination of Trace Amounts of Palladium with 2-(2-Quinolylazo)-1,5-Diaminobenzene

根据2-（2-喹啉偶氮）-1，5-二氨基苯（QADAB）与钯的显色反应及MCI—GEL反相固相萃取小柱对显色络合物的固相萃取，建立了一种测定痕量钯的方法。在0．2～3.0mol·L^-1高氯酸介质中，溴化十六烷基三甲胺（CTMAB）存在下，QADAB与钯反应生成2：1稳定络合物，该络合物可被MCI—GEL反相固相萃取小柱萃取富集，富集的络合物用丙酮洗脱后用光度法测定，在丙酮介质中体系的最大吸收波长为600nm，表观摩尔吸光率为9．63×10^4L·mol^-1·cm^-1。钯质量浓度在0．01～1.5mg·L^-1内符合比耳定律，方法用于几种实样中痕量钯的测定，测得回收率在86％～96％间。

Based on the color reaction between 2-（2-Quinolylazo）-1, 5-diaminobenzene （QADAB） and palladium（ Ⅱ ）, and its solid-phase extraction on the small column packed with the MCVGEL reverse phase fine separation filler, a new method of photometric determination of trace amounts of Pd（ Ⅱ ） was proposed. In an acidic medium of 0.2-3. 0 mol·L^-1 HClO4 and in the presence of CTMAB, a stable coordination complex of QADAB and Pd（ Ⅱ ） with mole ratio （R ： Pd） of 2 to 1 was formed, which was extracted and enriched on the RP-SPE column, and then eluted with acetone. The absorbance of the color complex in acetone solution was measured at its absorption maxima of 600 nm, with its molar absorptiwty of （ε600） 9. 63× 10^4L·mol^-1· cm^-1. Beer＇s law was held in the range of 0. 01 to 1.5 mg ·L^-1 of Pd（ Ⅱ ）. In its application to the analysis of some substantial samples, values of recovery found were in the range of 86%-96%% .