Chelating resin immobilizing carboxymethylated polyethyleneimine for selective solid-phase extraction of trace elements: Effect of the molecular weight of polyethyleneimine and its carboxymethylation rate
Chelating resin immobilizing carboxymethylated polyethyleneimine for selective solid-phase extraction of trace elements: Effect of the molecular weight of polyethyleneimine and its carboxymethylation rate
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DOI：
10.1016/j.talanta.2015.09.071
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发表时间：
2016-01-15
期刊：
影响因子：
6.1
通讯作者：
Inoue, Yoshinori
中科院分区：
文献类型：
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作者：
Kagaya, Shigehiro;Kajiwara, Takehiro;Inoue, Yoshinori
研究了聚乙烯亚胺（PEI）的分子量及其羧甲基化速率（CM/N）对固定化羧甲基化PEI的螯合树脂选择性固相萃取能力的影响。通过固定化二乙烯三胺、三乙烯四胺、四乙烯五胺、五乙烯六胺、PEI 300（分子量约为10000）等制备了24种螯合树脂。300）和PEI 600（MW=约. 600)在甲基丙烯酸酯树脂上，然后用不同量的一氯乙酸钠进行羧甲基化。当使用具有大致相同CM/N比（0.242-0.271）的树脂时，在酸性和弱酸性条件下，Cd、Co、Cu、Fe、Ni、Pb、Ti、Zn和碱土金属元素的回收率随着PEI分子量的增加而增加;然而，Mo和V的萃取行为仅受到轻微影响。这可能是由于树脂中N含量的增加，导致羧酸基团的增加;固定在树脂上的PEI的分子量的差异对选择性萃取能力的影响不明显。CM/N比显著影响各种元素的萃取行为。在酸性和中性条件下，Cd、Co、Cu、Fe、Ni、Pb、Ti和Zn的回收率随CM/N值的增加而增加。然而，在这些条件下，当使用具有低CM/N比的树脂时，碱土元素的回收率相当低。这可能是由于这些元素与氨基羧酸和胺的络合物的不同稳定常数，以及元素与CM-PEI中的质子化氨基之间的静电排斥。Mo和V的回收率随着CM/N值的增加而降低或变化，表明这些元素的提取主要通过阴离子交换反应发生。对于含有大量碱金属和碱土金属元素的样品中痕量元素的分离和富集，发现CM/N=0.131（Cu（II）萃取容量为0.37 mmol g（-1））的CM-PEI 600树脂是最合适的，因为它在酸性和中性条件下几乎不萃取碱金属和碱土金属元素。该树脂被证明是方便的分离和富集镉，钴，铜，铁，锰，钼，镍，铅，V，和锌的认证参考材料（EnviroMAT EU-L-1废水和ES-L-1地下水）和市售食盐。(C)2015 Elsevier B. V.版权所有。
The effect of the molecular weight of polyethyleneimine (PEI), defined as a compound having two or more ethyleneamine units, and of its carboxymethylation rate (CM/N), represented by the ratio of ion-exchange capacity to the amount of N on the resin, on the selective solid-phase extraction ability of the chelating resin immobilizing carboxymethylated (CM) PEI was investigated. The chelating resins (24 types) were prepared by immobilization of diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, PEI300 (MW=ca. 300), and PEI600 (MW=ca. 600) on methacrylate resins, followed by carboxymethylation with various amounts of sodium monochloroacetate. When resins with approximately the same CM/N ratio (0.242-0.271) were used, the recovery of Cd, Co, Cu, Fe, Ni, Pb, Ti, Zn, and alkaline earth elements increased with increasing the molecular weight of PEIs under acidic and weakly acidic conditions; however, the extraction behavior of Mo and V was only slightly affected. This was probably due to the increase in N content of the resin, resulting in an increase in carboxylic acid groups; the difference in the molecular weight of PEIs immobilized on the resin exerts an insignificant influence on the selective extraction ability. The CM/N ratio considerably affected the extraction behavior for various elements. Under acidic and neutral conditions, the recovery of Cd, Co, Cu, Fe, Ni, Pb, Ti, and Zn increased with increasing CM/N values. However, under these conditions, the recovery of alkaline earth elements was considerably low when a resin with low CM/N ratio was used. This is presumably attributed to the different stability constants of the complexes of these elements with aminocarboxylic acids and amines, and to the electrostatic repulsion between the elements and the protonated amino groups in the CM-PEI. The recovery of Mo and V decreased or varied with increasing CM/N values, suggesting that the extraction of these elements occurred mainly by the anion-exchange reaction. For the separation and preconcentration of trace elements in samples containing large amounts of alkali and alkaline earth elements, the CM-PEI600 resin with CM/N=0.131 (Cu (II) extraction capacity, 0.37 mmol g(-1)) was found to be the most suitable because it scarcely extracts alkali and alkaline earth elements under acidic and neutral conditions. This resin proved to be convenient for separating and preconcentrating Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, V, and Zn in the certified reference materials (EnviroMAT EU-L-1 wastewater and ES-L-1 ground water) and commercially available table salt. (C) 2015 Elsevier B.V. All rights reserved.