Analytical Chemistry Division, BARC, Trombay, Mumbai 400 085, India.
J Hazard Mater. 2013 Nov 15;262:265-73. doi: 10.1016/j.jhazmat.2013.08.053. Epub 2013 Aug 27.
A flat sheet sorbent with poly(hydroxamic acid) groups anchored on the microporous structure of poly(propylene) membrane was developed and applied for the preconcentration and determination of heavy elements from natural waters. The designing of the sorbent involved UV-irradiation induced graft polymerization of acrylamide using N,N'-methylene-bis-acrylamide (MBA) as the crosslinker on the poly(propylene) base followed by chemical modification of the grafted membrane to generate crosslinked poly(hydroxamic acid) (PHA) groups in its pores. The synthesized PHA-membrane was found to preconcentrate U, V, Cu, Cr, Fe and Pb quantitatively (95%) from aqueous samples over a wide pH range of 4-9. The sorbed trace elements were quantified by direct analysis of the membrane using Energy Dispersive X-ray Fluorescence (EDXRF). To test the applicability of the developed sorbent to real samples, interference effect of common matrix elements like Na, K, Ca and Mg on the uptake of the analytes at sub μg mL(-1) level was studied. The PHA sorbent was found to be immune to interferences from Na, K and Mg up to 1000 μg mL(-1) and Ca up to 100 μg mL(-1) for an analyte concentration of 1 μg mL(-1). The method detection limit for EDXRF measurement was 6-30 ng using a 2 cm × 2 cm sorbent.
一种将多羟基肟酸基团固定在聚丙烯膜微孔结构上的扁平片状吸附剂被开发出来，并应用于从天然水中预浓缩和测定重金属元素。该吸附剂的设计涉及使用 N,N'-亚甲基双丙烯酰胺（MBA）作为交联剂，在聚丙烯基体上进行丙烯酰胺的紫外光引发接枝聚合，然后对接枝膜进行化学修饰，在其孔中生成交联的多羟基肟酸（PHA）基团。合成的 PHA 膜被发现能够在 4-9 的宽 pH 范围内从水样中定量（95%）预浓缩 U、V、Cu、Cr、Fe 和 Pb。通过使用能量色散 X 射线荧光（EDXRF）直接分析膜来定量吸附的痕量元素。为了测试所开发的吸附剂在实际样品中的适用性，研究了常见基质元素如 Na、K、Ca 和 Mg 对亚微克 mL(-1)水平分析物摄取的干扰效应。发现 PHA 吸附剂对 Na、K 和 Mg 的干扰具有免疫力，在 1μg mL(-1)的分析物浓度下，Na、K 和 Mg 的浓度高达 1000μg mL(-1)，Ca 的浓度高达 100μg mL(-1)。使用 2 cm × 2 cm 的吸附剂，EDXRF 测量的方法检出限为 6-30ng。
