茶叶中铁含量的测定

Spectrophotometer determination of iron in tea

采用邻二氮菲分光光度法直接测定了茶叶中铁离子含量.用于法灰化法处理样品,先把样品置于520℃左右马弗炉中灰化,使铁游离出来,再用盐酸羟胺将三价铁还原成二价铁,然后在510 nm波长处测定橙红色络合物Fe(Phen)_3^(2+)的吸光度,由标准曲线及样品的吸光度可查得溶液的铁含量.此法快速、简单、准确,可为指导人们在饮茶的同时进行补铁提供理论依据.

In this paper,the iron contents of several kinds of tea has been determined directly by Phenanthroline spectrophotometry. The samples were disposed by using dry ash test and burned in 520℃ muffle furnace into ashes. Then the free Fe^3＋ was reduced to Fe^2＋ by hydroxylamine hydrochloride and the absorbance of the orange complex Fe（Phen）3^2＋ was obtained by spectrophotometry at the wave 510 nm. The iron contents was calculated through the standard curve and the absorbance. The method is simple, rapid, accurate. The result provides theoretical basis for guiding people to replenish iron by drinking tea.