N-2-噻唑基水杨醛亚胺西佛碱的合成及其与铍的荧光熄灭反应的研究及应用

Synthesis and Studies on Fluorimetric Quenching Reaction Between Beryllium and a New Spectrofluorimetric Reagent N 2 Thiazol Salicylimino Schiffs Base

合成了新型荧光试剂Ｎ－２－噻唑基水杨醛亚胺西佛碱，测定了试剂的离解常数．该试剂与碱土金属（Ｂｅ、Ｍｇ、Ｃａ、Ｓｒ、Ｂａ）离子能形成配合物，从而使该试剂λｅｘ／ｅｍ＝３８０／４９６ｎｍ的荧光熄灭，其熄灭的荧光程度随碱土金属离子半径的减小而增大．利用此配合反应建立了铍的分析方法，铍量在０．１～０．５μｇ／１０ｍＬ范围内与△ＩＦ成线性关系，检出限为１．９ｐｐｂ；测得的相对标准偏差为１．２２％．考察了３０余种共存组分的干扰情况．方法应用于测定水样中痕量铍，回收率在９７．５～１０２．５％．

A new fluorescent reagent, N 2 thiazol salicyldimino schiffs base(N 2 TSDASB) was synthesized and characreized by elemental analysis, IR and UV. Its ionization constants were established spectrophometrically. This reagent exhibited a fluorescent excitation and emission maxima at 380 nm and 496nm, respectively. In the pH 8.1 buffer solution the fluorescent reaction of this reagent with beryllium, magnesium, calcium, strontium and barium formed complexes to cause its fluorescence quenching. The less the ionic radial of alkali earth metals, the greater their fluorescence quenching intensities are. Based on this chelation, a spectrofluorimetric method was developed for the determination of beryllium. The linear range of the method is from 0.1-0.5μg/10mL. The detection limit is 1.9 ppb. The relative standard deviation was 1.22%. Interferences of other ions were studied. The method has been successfully applied to the determination of beryllium in mineral water with recoveries of 97.5-102.5%.