摘要
本文研究了在聚乙烯醇-124存在下,汞(Ⅱ)-乙基罗丹明B_碘化物超高灵敏显色体系及其反应机理。缔合物λ_(max)=605nm,表观摩尔吸光系数ε_(605nm)=1.14×10~6L.mol^(-1).cm^(-1)。汞(Ⅱ)浓度在0—2.5μg/25ml时符合比耳定律。方法可用于水样及地球化学标样中痕量汞的测定。
A highly sensitive spectrophotometric method has been developed for determination of trace mercury,based on the formation of a complicated ion-association complex of mercury (Ⅱ) with ethyl rhodamine B (ERB) and iodide in the presence of polyvinyl alcohol-124. The maximum adsorption of the ion-association complex is at 605 nm and its apparent molar absorptivity is 1.14×10~6 L·mol^(-1)·cm^(-1) at 605nm, Beer's law is obeyed for 0—2.5 μg/25ml of mercury, The interference of 18 diverse ions was studied. The molar ratio of Hg to ERB was found to be 1:4 as established by Job's method of continuous variation and the molar ratio method. The complex is supposed to be a complicated ion-association complex with the possible formula [(ERB+)_2·(HgI_4^(2-))]·12 [ERB^+·I^-]· The proposed method has been used for the determination of trace mercury in tap water, lake water and geological sample with satisfactory results. The reaction mechanism has been discussed.
出处
《分析化学》
SCIE
EI
CAS
CSCD
北大核心
1989年第2期112-117,共6页
Chinese Journal of Analytical Chemistry
基金
国家自然科学基金资助课题
关键词
显色反应
乙基罗丹明B
碘化物
汞
Extra-high sensitivity
Mercury
Ethyl rhodamine B
