UNMODIFIED MULTI-WALLED CARBON NANOTUBES AS SORBENT MATERIAL IN FLOW INJECTION ON-LINE SORBENT EXTRACTION PRECONCENTRATION SYSTEM FOR CADMIUM DETERMINATION BY FLAME ATOMIC ABSORPTION SPECTROMETRY
UNMODIFIED MULTI-WALLED CARBON NANOTUBES AS SORBENT MATERIAL IN FLOW INJECTION ON-LINE SORBENT EXTRACTION PRECONCENTRATION SYSTEM FOR CADMIUM DETERMINATION BY FLAME ATOMIC ABSORPTION SPECTROMETRY
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DOI：
10.1080/00032719.2012.670792
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发表时间：
2012-01-01
影响因子：
2
通讯作者：
Paschalidou, Magdalini
中科院分区：
文献类型：
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作者：
Anthemidis, Aristidis N.;Paschalidou, Magdalini
研究了未经改性的多壁碳纳米管（MWCNTs）作为流动注射在线微柱预富集-火焰原子吸收光谱法测定天然水样中镉的疏水性吸附材料。该方法基于分析物与二乙基二硫代氨基甲酸钠之间的在线螯合络合物形成和保留在MWCNTs表面。用甲醇对分析物进行定量洗脱，然后将甲醇送入原子吸收光谱雾化器进行雾化和测量。微柱中填充了MWCNTs和二氧化硅珠的混合物，以尽量减少流动系统中由MWCNTs纳米尺寸引起的背压。对影响该方法性能的各种因素进行了深入研究。预富集时间为180s时，增强因子为54，检出限（3s）为0.24 μ g -1，在5.0 μ gL(-1) Cd（II）浓度水平下，相对标准偏差精密度为3.2%。将该方法应用于环境水样的分析，并通过标准物质和回收实验对其准确度进行了评价。
Unmodified multi-walled carbon nanotubes (MWCNTs) were demonstrated as hydrophobic sorbent material for flow injection on-line microcolumn preconcentration coupled with flame atomic absorption spectrometry for cadmium determination in natural water samples. The method was based on on-line chelate complex formation between the analyte with sodium diethyldithiocarbamate and retention onto the surface of MWCNTs. Quantitative elution of the analyte was achieved with methanol which was whereupon delivered to the FAAS nebulizer for atomization and measurement. The microcolumn was packed with a mixture of MWCNTs and silica beads in order to minimize the generated back-pressure in the flow system which arises from the nano dimensions of MWCNTs. All factors affecting the performance of the proposed method were studied thoroughly. For a 180s preconcentration time the enhancement factor was 54, the detection limit (3s) was 0.24 mu g L-1, and the precision as relative standard deviation at a 5.0 mu gL(-1) Cd(II) concentration level was 3.2%. The method was applied to the analysis of environmental water samples and the accuracy evaluated via certified reference material and recovery experiments.