摘要
将干海带在碳酸钠溶液中熬煮,滤液酸化并用双氧水氧化,采用电位滴定法控制氧化析碘过程;以低沸点有机溶剂为萃取剂,采用低温减压分离方法,实现有机溶剂和单质碘的分离,得到的碘收率较高（62.5%）,可用差量法称量。探索了滤液pH、双氧水浓度和萃取溶剂对实验结果的影响。分别采用碘量法和分光光度法检验了提取碘的纯度。研究结果表明：滤液pH为2.5~3.5时,用质量分数为2%的双氧水氧化析碘结果比较理想;与二氯甲烷相比,无水乙醚萃取含I2水溶液效率更高。碘量法和分光光度法测定数据较为吻合,都可以用来测定水溶液的碘含量。
A low-temperature vacuum method has been developed for separation of iodine（I2） from kelp,which involves cooking dry kelps in Na2CO3 aqueous solution,acidifying and oxidizing the filtrate,extraction of I2 with organic solvents having low-boiling points,and final isolation of I2 from the solvent at low temperature and reduced pressure.Formation of I2 in the acidified solution was controlled by potentiometric titration using H2O2 aqueous solution as the oxidant.Yield of I2 was relatively high（62.5%） which can be quantified by delta algorithm.Influences of separation conditions including pH of the filtrate,concentration of H2O2,and organic solvents on experiment result were comparatively investigated.Purity of I2 acquired by this method was respectively determined by iodimetry and spectrophotometry.Results showed that it′s suitable for separation of I2 in the pH range of 2.5~3.5 using 2%（mass fraction） H2O2 as the oxidant.In comparison with that of CH2Cl2,the extraction efficiency of anhydrous（CH3CH2）2O was relatively higher for isolation of I2 in aqueous solution.Data of iodimetry and spectrophotometry agreed well so that the both methods were feasible for quantifying I2 content in aqueous solution.
出处
《无机盐工业》
CAS
北大核心
2011年第1期52-55,共4页
Inorganic Chemicals Industry
关键词
碘
双氧水
电位滴定法
碘量法
海带
lodine
H2O2
potentiometric titration
iodimetry
kelp
