13X分子筛微柱预富集-流动注射火焰原子吸收光谱法测定水中痕量铜

来源期刊：冶金分析2010年第9期

论文作者：于洪梅 孙巍 宋华

文章页码：23 - 27

关键词：13X分子筛； 火焰原子吸收光谱法； 铜； 预富集； 流动注射

Key words：13X molecular sieve； flame atomic absorption spectrometry； copper； preconcentration； flow injection

摘    要：建立了13X分子筛微柱离子交换分离预富集-流动注射火焰原子吸收光谱法检测水中痕量铜的新分析方法。铜以自由离子的形式而非螯合的形式滞留在13X分子筛微柱上,然后用0.5 mL 10%(V/V)HNO3洗脱,通过原子吸收光谱法进行检测。并对流动注射的一些主要参数和各种干扰离子进行了研究。在最优条件下,富集2 min即进样体积为18 mL,测得的线性范围为0.002～0.150μg/mL,检出限为0.5μg/L(3σ,n=11),相对标准偏差(RSD)为1.1%(0.05μg/mL,n=11),富集系数为23.3,采样频率为30次/h。可以通过增加进样体积到36 mL,得到更低的检出限为0.28μg/L。将该方法用于各种水样中铜的分析,加标回收率符合分析要求。

Abstract: A novel ion-exchange separation and proconcentration method with 13X molecular sieve microcolumn was developed for the determination of trace copper ion in water samples combining with flame atomic absorption spectrometry (FAAS).Copper was quantitatively retained on the 13X molecular sieve microcolumn in the form of free ions rather than chelate.The copper ions were eluted with 0.5 mL of 10 %(V/V) nitric acid solution as eluent and determined by FAAS.Some important flow injection variables affecting preconcentration were optimized and interference level of various ions were also investigated.Under the optimum conditions with enriching for 2 min and a sampling volume of 18 mL,the linear range was 0.002-0.150 μg/mL and detection limit was 0.5 μg/L(3σ,n=11) with enrichment factor of 23.3,relative standard deviation (RSD) of 1.1 %(0.050 μg/mL,n=11) and sampling frequency of 30/h.When the injection volume reached 36 mL,a lower detection limit(0.28 μg/L) was obtained.The present method was successfully applied for the determination of trace copper in various water samples with satisfactory recoveries.