2,4-二羟基苯乙酮缩三羟基甲基氨基甲烷的合成及其在稀土矿样中铽的痕量荧光分析中的应用

合成了一种新的席夫碱配体2,4-二羟基苯乙酮缩三羟基甲基氨基甲烷.该配体与铽(Ⅲ)的配合物的荧光强度在磷酸钠或六次甲基四胺的存在下可增强18或26倍.有机溶剂CH3CN,DMF,丙酮,THF,DMSO,CH3OH,C2H5OH的添加可使其荧光强度进一步增加3～19倍.其中,用CH3CN作溶剂时荧光增加倍数最大,Tb-HL-HMTM体系荧光最强.pH=6.0时,激发和发射波长分别是355和545 nm.在理想情况下,荧光强度与Tb3+离子浓度成正比.对于HL-Na3PO4-CH3CN体系,线性范围2.3×10-10～5.8×10-5 mol/L,检测限2.0×10-10 mol/L,对于HL-HMTM-CH3CN体系,线性范围9.8×10-11～7.2×10-5 mol/L,检测限9.0×10-11 mol/L.基于此对Tb3+进行定量测定,该分析方法简单、快速、灵敏、干扰小.同时对荧光增强的机理进行了分析和讨论.

Synthesis of new Schiff base 2,4-dihydroxyl-aceto- phenonetriaminotriethylamine and its application in fluorescence determination of trace amounts of terbium(Ⅲ) in a high purity yttrium oxide

A new Schiff base ligand, 2, 4-dihydroxyl-acetophenonetriaminotriethylamine(HL), was synthesized and its fluorescence intensity with terbium(Ⅲ) increased by about 18 fold in the presenc of sodium phosphate(Na3PO4) or increased by about 26 fold in the presenc of hexamethylene tetramine(HM- TM).And when organic solvents(CH3CN, DMF, acetone, THF, DMSO, CH3OH, and C2H5OH) were added into the above system, the fluorescence intensities were further enhanced by about 3～19 folds, which was observed to be highest for the Tb-HL-HMTM-CH3CN system(to be about 500 fold). The spectrofluorimetric determination of trace amount of Tb3+ based on the phenomenon was carried out. The excitation and emission wavelengths are 355 and 545 nm, respectively. Under optimal conditions, the fluorescence intensities vary linearly with the concentration of Tb3+ in the range 2.3×10-10 ～5.8×10-5 mol/L with a detection limit of 2.0×10-10 mol/L(for HL-Na3PO4-CH3CN system) or 9.8×10-11 ～7.2×10-5 mol/L with a detection limit of 9.0×10-11 mol/L (for HL-HMTM-CH3CN system). The interferences of some rare earth metals and other inorganic ions were described. The method proves to be a selective, sensitive,rapid and simple analytical procedure for the determination of terbium(Ⅲ) in high-purity yttrium oxide and synthetic samples. The mechanism for the fluorescence enhancement was also studied.