Visual test of subparts per billion-level copper(II) by Fe3O4 magnetic nanoparticle-based solid phase extraction
Zhi-qiang Tan1, Jing-fu Liu, Gui-bin Jiang
1State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085, China.
Abstract:
By combining Fe(3)O(4) magnetic nanoparticle-based solid phase extraction with a gold nanoparticle-based visual test, a novel method was developed for the field assay of Cu(ii) in environmental water at subparts per billion-levels within 30 min. When a 200 mL water sample was treated with 12.5 mg L(-1) Fe(3)O(4) nanoparticles by the proposed procedure, the detection limit with the naked eye was 0.2 μg L(-1) Cu(ii). The proposed method is very specific to Cu(ii), with tolerance against at least 100-fold amounts of other environmentally relevant metal ions except for Hg(ii) (25-fold), and was successfully applied to the detection of trace Cu(ii) in tap water, river water, and treated wastewater, and results agreed well with that determined by inductively coupled plasma-mass spectrometry (ICP-MS).
