Ahmad Panahi Homayon, Morshedian Jalil, Mehmandost Nasrin, Moniri Elham, Galaev Igor Yu
Department of Chemistry, Islamic Azad University, Central Tehran Branch, Iran.
J Chromatogr A. 2010 Aug 6;1217(32):5165-72. doi: 10.1016/j.chroma.2010.06.012. Epub 2010 Jun 9.
A method is reported for surface grafting of polymer containing a functional monomer for metal chelating, poly[1-(N,N-bis-carboxymethyl)amino-3-allylglycerol-co-dimethylacrylamide] (poly(AGE/IDA-co-DMAA) onto silica modified by silylation with 3-mercaptopropyltrimethoxysilane. Monomer 1-(N,N-bis-carboxymethyl)amino-3-allylglycerol (AGE/IDA) was synthesized by reaction of allyl glycidyl ether with iminodiacetic acid. The resulting sorbent has been characterized using FT-IR, elemental analysis, thermogravimetric analysis (TGA), FT-Raman and scanning electron microscopy (SEM) and evaluated for the preconcentration and determination of trace Pb(II) in human biological fluid and environmental water samples. The optimum pH value for sorption of the metal ion was 5.5. The sorption capacity of functionalized resin was 15.06 mg g(-1). The chelating sorbent can be reused for 15 cycles of sorption-desorption without any significant change in sorption capacity. A recovery of 96.2% was obtained for the metal ion with 0.5 M nitric acid as eluting agent. The profile of lead uptake by the sorbent reflects good accessibility of the chelating sites in the poly(AGE/IDA-co-DMAA)-grafted silica gel. Scatchard analysis revealed that the homogeneous binding sites were formed in the polymers. The equilibrium adsorption data of Pb(II) by modified resin were analyzed by Langmuir, Freundlich, Temkin and Redlich-Peterson models. On the basis of equilibrium adsorption data the Langmuir, Freundlich and Temkin constants were determined as 0.70, 1.35 and 2.7, respectively at pH 5.5 and 20 degrees C. Isotherms have also been used to obtain the thermodynamic parameters such as free energy, enthalpy and entropy of adsorption.
报道了一种用于将含有金属螯合功能单体的聚合物，即聚1-(N,N-双羧甲基)氨基-3-烯丙基甘油-co-二甲基丙烯酰胺表面接枝到用3-巯丙基三甲氧基硅烷硅烷化改性的二氧化硅上的方法。单体1-(N,N-双羧甲基)氨基-3-烯丙基甘油(AGE/IDA)通过烯丙基缩水甘油醚与亚氨基二乙酸反应合成。所得吸附剂已通过傅里叶变换红外光谱(FT-IR)、元素分析、热重分析(TGA)、傅里叶变换拉曼光谱和扫描电子显微镜(SEM)进行了表征，并用于人体生物流体和环境水样中痕量Pb(II)的预富集和测定。金属离子吸附的最佳pH值为5.5。功能化树脂的吸附容量为15.06 mg g(-1)。螯合吸附剂可重复使用15次吸附-解吸循环，吸附容量无任何显著变化。以0.5 M硝酸为洗脱剂时，金属离子的回收率为96.2%。吸附剂对铅的吸附曲线反映了聚(AGE/IDA-co-DMAA)接枝硅胶中螯合位点的良好可及性。Scatchard分析表明聚合物中形成了均匀的结合位点。用Langmuir、Freundlich、Temkin和Redlich-Peterson模型分析了改性树脂对Pb(II)的平衡吸附数据。根据平衡吸附数据，在pH 5.5和20℃下，Langmuir、Freundlich和Temkin常数分别确定为0.70、1.35和2.7。等温线也用于获得吸附的自由能、焓和熵等热力学参数。
