5-硝基水杨基荧光酮分光光度法测定茶叶中微量锰

<title>Spectrophotometric determination of trace manganese(Ⅱ) in tea with 5-nitro salicylfluorone

研究了在混合表面活性剂协同增敏作用下,锰(II) 5 硝基水杨基荧光酮(5 NSAF)的显色反应的条件。在pH9.8～10.6的H3PO4 HAC H3BO3 NaOH缓冲溶液中,Mn(Ⅱ)与5 NSAF形成1∶2的紫色络合物。ε=1.39×105L·mol-1·cm-1,Mn(Ⅱ)浓度在0～15mg/L范围内服从比耳定律。方法已用于茶叶标样中微量锰的测定。

<Abstrcat> The colour reaction of manganese(Ⅱ) with 5nitrosalicylfluorone(5NSAF) in the presence of cationic surfactant cetyltrimethylammonium bromide and emulsifier OP was studied. In the buffer solution of H3PO4HAcH3BO3NaOH at pH 9.8 to 10.6, manganese(Ⅱ) reacted with 5NSAF and form a 1∶2 purple complex in the presence of the mixed surfactants. The molar absorptivity was 1.39×105 L/mol·cm at 577 nm. Beer′s law was obeyed for manganese(Ⅱ) in the range of 0～15mg/L. This methed was applied to the determination of trace Mn(Ⅱ) in tea samples with satisfactory results.