Mohammadi S Z, Shamspur T, Karimi M A, Naroui E
Department of Chemistry, Payame Noor University, PO Box 19395-4697, Tehran, Iran.
ScientificWorldJournal. 2012;2012:640437. doi: 10.1100/2012/640437. Epub 2012 Apr 20.
This work investigates the potential of magnetic Fe(3)O(4) nanoparticles as an adsorbent for separation and preconcentration of trace amounts of lead from water samples prior to electrothermal atomic absorption spectrometry (ETAAS) determination. No chemical modifier is required in graphite furnace. Pb(II) ion was adsorbed on magnetic Fe(3)O(4) nanoparticles in the pH range of 5.5-6.5, and then magnetic nanoparticles (MNPs) were easily separated from the aqueous solution by applying an external magnetic field; so, no filtration or centrifugation was necessary. After extraction and collection of MNPs, the analyte ions were eluted using HNO(3) 1.0 mol L(-1). Several factors that may affect the preconcentration and extraction process, such as pH, type, and volume of eluent, amount of MNPs, sample volume, salting out effect, and interference ions were studied and optimized. Under the best experimental conditions, linearity was maintained between 0.005-0.5 ng mL(-1). Detection limits for lead were 0.8 ng L(-1) based on 3S(b). The relative standard deviation of seven replicate measurements of 0.05 ng mL(-1) of Pb(II) ions was 3.8%. Finally, the method was successfully applied to extraction and determination of lead ions in the water and standard samples.
本研究考察了磁性Fe(3)O(4)纳米颗粒作为吸附剂，用于在电热原子吸收光谱法（ETAAS）测定之前，从水样中分离和预富集痕量铅的潜力。石墨炉中无需化学改性剂。Pb(II)离子在pH为5.5 - 6.5的范围内吸附在磁性Fe(3)O(4)纳米颗粒上，然后通过施加外部磁场可轻松从水溶液中分离出磁性纳米颗粒（MNPs）；因此，无需过滤或离心。在提取和收集MNPs后，使用1.0 mol L(-1)的HNO(3)洗脱分析物离子。研究并优化了几个可能影响预富集和萃取过程的因素，如pH、洗脱剂的类型和体积、MNPs的量、样品体积、盐析效应以及干扰离子。在最佳实验条件下，线性范围保持在0.005 - 0.5 ng mL(-1)之间。基于3S(b)，铅的检测限为0.8 ng L(-1)。对0.05 ng mL(-1)的Pb(II)离子进行七次重复测量的相对标准偏差为3.8%。最后，该方法成功应用于水和标准样品中铅离子的萃取和测定。
