流动注射在线共沉淀火焰原子吸收光谱法测定氯化钴溶液中痕量铅

Determination of trace lead in cobalt chloride solution by flow injection on-line coprecipitation flame atomic absorption spectrometry

为解决钴冶金生产中痕量铅的快速监控问题,将流动注射在线富集分离技术与火焰原子吸收光谱检测方法相结合测定了氯化钴溶液中痕量铅。研究了铅的富集和分离条件,结果表明,用填充脱脂棉的微型锥形过滤器作为过滤柱,以硝酸铁作为共沉淀剂,在pH10的氨性缓冲介质中铁和铅生成氢氧化物共沉淀,富集在过滤柱上,可与高钴基体分离,过滤柱上铅经盐酸(1+9)洗脱后用火焰原子吸收光谱法测定。在283.3nm波长处测得铅的特征浓度为0.008mg/L(1%吸收),检出限为5μg/L,样品中铅测定结果的相对标准偏差为6.1%(n=11),满足了快速分析的要求。

To realize real time monitoring of trace lead in metallurgical production of cobalt,flow injection online enrichment separation technique coupled with flame atomic absorption spectrometry was used to determine trace lead in cobalt chloride solution.The enrichment and separation conditions of lead were studied.The result indicated that by using miniature cone filter filled with degreasing cotton as filtration column and ferric nitrate as co-precipitant,in the ammonia buffer medium of pH10,iron and lead produced hydroxide co-precipitation to concentrate on the filter column and separate from high cobalt matrix.The lead on the filter column was eluted by hydrochloric acid（1＋9） and determined by flame atomic absorption spectrometry.At the wavelength of 283.3 nm,the characteristic concentration of lead was 0.008 mg/L（1% absorption）,the detection limit was 5 μg/L and RSD was 6.1%（n=11）.It can meet the requirement of fast analysis.