将3,3′,5,5′-四甲基联苯胺和苯并噻唑类试剂结合,并引入杂环三氮烯结构,合成了新荧光试剂双(2-苯并噻唑重氮氨基)-3,3′,5,5′-四甲基联苯(BBTDTMB),其结构经红外光谱、核磁共振谱和元素分析证实.研究结果表明,在碱性介质中,该试剂在λex/λen=342nm/420nm处产生强荧光,并且Ag(Ⅰ)对其荧光有很好的猝灭作用,因而建立了BBTDTMB测定Ag(Ⅰ)的新荧光分析方法.该方法的线性范围为1.0~240μg/L,检测限为0.5μg/L,应用于人发、茶叶中的AS(Ⅰ)的测定,结果令人满意。
With the aid of combining 3,3′,5,5′-tetramethylbiphenyl with benzothiazole through triazene group, a new fluorescent reagent bis ( 2-benzothiazolydiazoamino ) -3,3′,5,5′-tetramethylbiphenyl (BBTDTM B ) was synthesized. The product was confirmed by means of elemental analysis, ^1H NMR and infrared spectra. Its excitation and emission wavelengths were 342 nm and 420 nm in a basic medium, respectively. This new reagent reacts with Ag( Ⅰ ) in a slightly basic medium to form a 1:2 complex, by which silver ion causes the fluorescence quenching of the new fluoresent reagent. The reaction showed a high selectivity and a high sensitivity for Ag( Ⅰ ). A new spectrofluorimetric method for the determination of trace Ag( Ⅰ ) with this reagent was developed. The linear range of determination for Ag ( Ⅰ ) was 1.0-240 μg/L with a detection limit of O. 5 μg/L. The method is a selective, sensitive, and simple analytical procedure, and was used for the determination of trace Ag( Ⅰ ) in hair and tea with satisfactory results.