氯化钠-α-亚硝基-β-萘酚-酚酞体系分离富集钴(Ⅱ)

来源期刊：冶金分析2011年第1期

论文作者：涂常青 温欣荣

文章页码：66 - 69

关键词：钴(Ⅱ)； α-亚硝基-β-萘酚； 酚酞； 分离富集

Key words：cobalt (Ⅱ)； α-nitroso-β-naphthol； phenolphthalein； separation and enrichment

摘    要：建立了一种以微晶酚酞作吸附剂分离富集痕量Co(Ⅱ)的新方法。探讨了α-亚硝基-β-萘酚(HL)及酚酞用量、盐的种类及用量、酸度等因素对Co²⁺富集率的影响,得到了分离富集钴(Ⅱ)的最佳条件,讨论了Co²⁺的富集机理。结果表明:控制pH值为5.0,在1.0g NaCl存在下,当2.0g/L α-亚硝基-β-萘酚溶液用量和5%酚酞溶液用量分别为0.60mL和0.10mL时,Co²⁺与α-亚硝基-β-萘酚(HL)反应生成的红棕色螯合物沉淀CoL₃被定量吸附在微晶酚酞上,Co²⁺被定量富集,而Zn²⁺,Mn²⁺,Al³⁺,Cd²⁺在此条件下不被吸附,从而实现了Co²⁺与这些离子的定量分离。方法用于合成水样中微量Co²⁺的定量富集分离测定,富集率为99.8%～108.6%。

Abstract:

A novel separation and enrichment method of cobalt (Ⅱ) using microcrystalline phenolphthalein as adsorbent was established.The effect of addition amount of α-nitroso-β-naphthol(HL) and phenolphthalein,the type and dosage of salt,and acidity on the enrichment yield of Co²⁺ was investigated.The optimal separation and enrichment conditions of cobalt(Ⅱ) were obtained.The enrichment mechanism of Co²⁺ was discussed.The results showed that Co²⁺ could react with HL to form reddish brown chelate precipitate (CoL₃) which was quantitatively adsorbed on microcrystalline phenolphthalein under the following conditions:at pH 5.0;in the presence of 1.0 g of NaCl;the dosages of 2.0 g/L HL and 5% phenolphthalein solution were 0.60 mL and 0.10 mL,respectively.Consequently,Co²⁺ could be quantitatively enriched,while Zn²⁺,Mn²⁺,Al³⁺ and Cd²⁺ were not adsorbed under these conditions,realizing the quantitative separation of Co²⁺ from these ions.This method had been applied to the quantitative enrichment,separation and determination of micro Co²⁺ in synthetic water samples.The enrichment yield was 99.8%-108.6%.