摘要
利用Na+型732#阳离子交换树脂优先与Ca(Ⅱ)交换缔合,形成二元缔合体系(R- Ca(Ⅱ)),在酸性介质中离子交换树脂负载的Ca(Ⅱ)与乙酰基偶氮羧在树脂上配位显色,形成离子交换树脂 Ca(Ⅱ) 乙酰基偶氮羧三元缔合配位显色体系,该三元体系在720nm波长处有最大吸收,建立了薄层树脂相测定钙的新方法。由于离子交换树脂与Ca(Ⅱ)二元交换缔合和树脂负载Ca(Ⅱ)与乙酰基偶氮羧配位的选择性,使本法选择性极高(EDTA存在下大多数共存离子不影响测定)。由于三元缔合配位体系的形成增大了吸光截面积,扩大了π电子离域空间,加之树脂颗粒变小(孔径为0 074mm以下),晾干浓缩提高了方法灵敏度,表观摩尔吸光系数ε720=9 1×105L·mol-1·cm-1,比水相光度法灵敏度提高15 4倍,测定5 0μgCa(Ⅱ)6次,RSD=2.9%,实测了二次精制盐水中Ca(Ⅱ),线性范围为0～9 0μg/mL,检出限为1 4μg/L。
Based on the association of model 732 cation exchange resin and Ca(Ⅱ), a binary association system R-Ca(Ⅱ) was formed. Acetylazoformic acid was coordinated with R-Ca(Ⅱ) and formed R-Ca(Ⅱ)-acetylazoformic acid ternary association system, which had a maximum absorption at 720 nm. A new spectrophotometric method based on the thin layer resin of this ternary association system was developed. The molar absorption coefficient was 9.1×10~5 L·mol^(-1)·cm^(-1). For 5.0 μg Ca, the RSD of 6 determinations was 2.9%. The of detection limit of Ca in salt solution was 1.4 μg/L.
出处
《分析试验室》
CAS
CSCD
北大核心
2004年第6期35-37,共3页
Chinese Journal of Analysis Laboratory
关键词
薄层
树脂相光度法
钙
Thin layer resin
Spectrophotometry
Calcium
