钛-邻苯二酚紫-EDTA-溴化十六烷基吡啶多元配合物显色反应的研究

Study on Colour Reaction of Multicomplexes of TitaniumPyrocatechol VioletEDTACetylpyridinium Bromide

在 p H6 .2的 HAc- Na Ac缓冲液中 ,钛与邻苯二酚紫、EDTA、溴化十六烷基吡啶形成 1∶ 3∶ 2∶ 2的多元配合物 ,在 5 6 9.3nm处有最大吸收 ,摩尔吸光系数ε=5 .5× 1 0 4 L· mol- 1 · cm- 1 。钛量在 2—1 5 μg/ 2 5 m L范围内符合比耳定律。方法可用于工业硅中微量钛的测定。

In the HAcNaAc buffer solution at pH6.2,the colour reaction of titanium with pyrocatechol violet and the formation conditions and compositions of the polyatomic complexes in the presence of EDTA and cetylpyridinium bromide have been studied.The molar ratio of Ti to PV to EDTA to CPB are 1∶3∶2∶2.The maximum absorbance is at 569.3nm and the molar absorptivity is ~5.5×104L·mol^-1·cm^-1.Beer's law is obeyed in the range of 2—15μg Ti/25mL. This method has been applied to the spectrophotometric determination of microamount titanium in silicon metal.