2-吡啶甲醛缩(2'-吡啶亚胺基)肼的合成及其与钴(Ⅱ)的显色反应

Synthesis of 2-pyridine-formaldehyde condensation(2'-pyridine imido-group) hydrazine and its color reaction with cobalt(Ⅱ)

报道了新试剂2-吡啶甲醛缩（2＇-吡啶亚胺基）肼（PFPIH）的合成与鉴定，系统研究了该试剂与钴的显色反应条件及应用，建立了2-吡啶甲醛缩（2’-吡啶亚胺基）肼光度法测定微量钴的新方法。在PH7．8的弱碱性介质中，Co抖与PFPIH反应生成摩尔比为1：2的橙色络合物，其最大吸收波长为440nm，表观摩尔吸光系数ε440=1．01×10^4L·mol^-1·cm^-1，钴（Ⅱ）含量在0．200～5．00μg／mL范围内符合比尔定律，方法的检出限为0．022μg／mL。该试剂具有较好的灵敏度和选择性，已用于合金钢中微量钴的测定，相对标准偏差（n=6）为1．5％。

Synthesis and identification of a new reagent 2-pyridine-formaldehyde condensation （2＇-pyridine imido-group） hydrazine （PFPIH） were reported. The color reaction and its application of the reagent with cobalt was studied in detail. In weak alkaline medium at pH 7.8, PFPIH reacts with cobalt to form a orange complex with a molar ratio of 1 ： 2, showing maximum absorbance at 440 nm, and the apparent molar absorptivity of 1.01 × 10^4 L · mol^-1 · cm^-1. Beer＇s law was obeyed at 0. 200- 5. 00 μg/mL for Co^2＋. The reagent has been successfully applied to the spectrophotometric determination of micro amounts of cobalt in alloy steel with the RSD of 1.5%（n=6）.