新的测镍试剂5-Br-PTPF的合成及应用

SYNTHESIS OF 5-Br-PTPF AND SPECTROPHOTOMETRIC DETERMINATION OF NICKEL

本文报道新的选择性测镍试剂1—([5′-溴-2′-吡啶)-5-硫代碳酰胺基-3-苯基甲腊(5-Br-PTPF)的合成及其分光光度法测定微量镍的研究。该试剂在非离子和阳离子混合表面活性剂的存在下,在弱碱性介质中,镍与5-Br-PTPF形成1∶2的配合物,其表观摩尔吸光系数ε_(610)=3.4×10~4L·mol^(-1)·cm^(-1)。镍含量在0—17.5μg/25ml范围内符合比尔定律。试剂对镍的选择性较好,可直接用于合金钢样中微量镍的测定,方法简便、快速,结果满意。

The preparation of 1-(5'-bromo-2'-pyridyl)-5-thiocarbanyl-3-phenyl formazan (5-Br-PTPF) and the conditions for the spectrophotometric determination of microamount of Ni(Ⅱ) are described. This reagent combines with Ni (Ⅱ) to form a blue complex in the presence of cationic surfactant CPB and nonionic surfactant Triton X-100 in a buffer solution of pH8.9-9.7. The complex has a maximum absorption at 610nm. The molar absorptivity of 3.4×10~4L·mol^(-1)·cm^(-1). Beer's law is obeyed in the range of 0-17.5μg/25ml. This method has been applied to the spectrophotometric determination of microamount Ni (Ⅱ) in steels, alloys of aluminium with satisfactory results.