新显色剂NPBPDT的合成及在环境监测中的应用研究

研究了1(4硝基苯基)3(5溴吡啶)三氮烯(NPBPDT)的合成及其与汞的显色反应。在TX100存在下,pH值为11.5的Na2B4O7NaOH缓冲溶液中,该试剂能与汞发生显色反应,汞与NPBPDT形成摩尔比为1∶2型的黄色配合物,在440nm处有一最大正吸收峰,在535nm处有一最大负吸收。以440nm为参比波长,535nm为测量波长进行双波长测定,表观摩尔吸光系数为2.80×105Lmol·cm,汞的浓度在0～12μg25mL范围内符合比尔定律。用拟定方法测定废水中的微量汞,有较高的准确度和精密度。

STUDY ON THE SYNTHESIS OF A NEW CHROMOGENIC REAGENT AND ITS APPLICATION IN ENVIRONMENTAL MONITORING

This paper reports the synthesis of the new reagent 1-(4-nitrophenyl)-3-(5-bromopyridyl)-triazene(NPBPDT)and the color reaction of NPBPDT with mercury.In the presence of the surface active agent Triton X-100 and in the Na_2B_4O_7-NaOH medium of pH 11.5,the reagent form a yellow complex with mercury in the molar ratio of 1∶2.The molar absorptivity is 2.80×105 L/mol/cm by dual-wavelengh of 440 nm and determination wavelengh of 535 nm.Beer's law is obeyed in the range of 0～12 μg/25 mL.The method has been applied to the direct determination of mercury in waste water with satisfactory results.