水中微量汞的分光光度测定研究

摘要

为克服双硫腙光度法测定水样中汞的选择性差和条件要求苛刻等缺点，研究合成了新三氮烯类试剂——6-硝基苯并噻唑重氮氨基-4-硝基苯(NBTDAPNP)及试剂与汞的显色反应，提出了用分光光度测定汞的新方法。在弱碱介质中，汞与试剂形成1∶2的黄色络合物，用双波长法测定，表观摩尔吸光系数为2.18×105 L/(mol*cm)，汞量在0～10 μg/25 mL范围内符合比尔定律。应用于工业废水和环境水样中汞的测定，获得了满意的结果。%The synthesis of a new reagent nitrobenzothiazolyldiazoamino-p-nitrophenyl(NBTDAPNP) and its colour formation reaction with mercury are reported. In weak alkaline medium and in the presence of Triton X-100,mercury reacts with NBTDAPNP to form an orange-yellow complex which has component ratio of 1∶2. The maxium absorption of the complex is at 450 nm and 530 nm,determination by dual wavelength spectrophoto-metry,and apparent molar absorptivity is 2.18×105 L/(mol*cm). Beer's law is obeyed for mercury in the range of 0～12 μg/25 mL. The interference of various ions has been studied and the method has been used for the determination of micro amounts of mercury in wastewater with satisfactory results.