Centre for Environmental Studies, Anna University, Chennai 600 025, India.
J Hazard Mater. 2011 Jan 30;185(2-3):1131-9. doi: 10.1016/j.jhazmat.2010.10.023. Epub 2010 Oct 14.
A solid phase extraction method has been developed for the determination of copper, nickel and zinc ions in natural water samples. This method is based on the adsorption of copper, nickel and zinc on multiwalled carbon nanotubes (MWCNTs) impregnated with di-(2-ethyl hexyl phosphoric acid) (D2EHPA) and tri-n-octyl phosphine oxide (TOPO). The influence of parameters such as pH of the aqueous solution, amount of adsorbent, flow rates of the sample and eluent, matrix effects and D2EHPA-TOPO concentration have been investigated. Desorption studies have been carried out with 2 mol L(-1) HNO(3). The copper, nickel and zinc concentrations were determined by flame atomic absorption spectrometry. The results indicated that the maximum adsorption of copper, nickel and zinc is at pH 5.0 with 500 mg of MWCNTs. The detection limits by three sigma were 50 μg L(-1) for copper, 40 μg L(-1) for nickel and 60 μg L(-1) zinc. The highest enrichment factors were found to be 25. The adsorption capacity of MWCNTs-D2EHPA-TOPO was found to be 4.90 mg g(-1) for copper, 4.78 mg g(-1) for nickel and 4.82 mg g(-1) for zinc. The developed method was applied for the determination of copper, nickel and zinc in electroplating wastewater and real water sample with satisfactory results (R.S.D.'s <10%).
已开发出一种固相萃取法，用于测定天然水样中的铜、镍和锌离子。该方法基于铜、镍和锌在浸渍二-(2-乙基己基)磷酸(D2EHPA)和三正辛基氧化膦(TOPO)的多壁碳纳米管(MWCNTs)上的吸附。研究了水溶液 pH 值、吸附剂用量、样品和洗脱液流速、基质效应和 D2EHPA-TOPO 浓度等参数的影响。用 2 mol L(-1) HNO(3)进行解吸研究。铜、镍和锌的浓度用火焰原子吸收光谱法测定。结果表明，铜、镍和锌的最大吸附在 pH 5.0 时用 500 mg MWCNTs 进行。铜的检出限为 50 μg L(-1)，镍为 40 μg L(-1)，锌为 60 μg L(-1)。最高的富集因子为 25。MWCNTs-D2EHPA-TOPO 的吸附容量为铜 4.90 mg g(-1)，镍 4.78 mg g(-1)，锌 4.82 mg g(-1)。所开发的方法已用于电镀废水和实际水样中铜、镍和锌的测定，结果令人满意(R.S.D.'s <10%)。
