摘要
研究了DCF-CPA与稀土元素显色反应的条件。实验表明,DCF-CPA的最大吸收峰位于543nm处,试剂在高酸度下可与稀土元素形成稳定的蓝色络合物(λ_(max)=640～647nm,ε=0.50～1.21×10~5)。大多数常见金属元素的共存允许量可达毫克级以上。可用于铅、锡合金中稀土总量的直接测定。在2mol·l^(-1)盐酸体系中测定了铝合金中的稀土总量,结果令人满意。
The colour reaction of rare earths with2-(2-phosphophenylazo)-7-(2,6-dichloro-4-fluoro-phenylazo)-1,8-dihydroxynaphthalene-3,6-disul-fonic acid(DCF-CPA)has been studied.Exper-iments show that stable complexes can be formedin a solution of 2.0M HCl.The absorp- tion maxima of the reagent and complexes are543 nm and 640～647nm,respectively.The colourreaction has high sensitivity(molar absorptivityis 1.21×10~5 l·mol^(-1)·cm^(-1)for Ce)and goodselectivity.The tolerance quantity of many metalion interferences is in milligram level and thelolerance quantity of Pb(Ⅱ)(10mg),Sn(Ⅳ)(20mg)and Al(Ⅲ)(20mg)is larger than thatusing other chromogenic reagents as reportedbefore.Beer's law is obeyed in the concentrationrange of 0～25μg CeO_2/25ml and 0～20μg Y_2O_2/25ml.The contents of total RE in aluminium-based alloys can be determined directly withsatisfactory results.
出处
《化学试剂》
CAS
CSCD
北大核心
1990年第1期15-17,共3页
Chemical Reagents
基金
国家科学基金
