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Combining field‐amplified sample stacking with moving reaction boundary electrophoresis on a paper chip for the preconcentration and separation of metal ions
Author(s) -
Ouyang Liangfei,
Liu Qian,
Liang Heng
Publication year - 2017
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201600804
Subject(s) - detection limit , stacking , electrophoresis , capillary electrophoresis , chemistry , analytical chemistry (journal) , metal ions in aqueous solution , chromatography , metal , organic chemistry
A common drawback of paper‐based separation devices is their poor detection limit. In this study, we combined field‐amplified sample stacking with moving reaction boundary electrophoresis on a paper chip with six array channels for the parallel separation and concentration of multiple samples. With a new hyphenated technique, the brown I 2 from the Fe 3+ /I − oxidation–reduction reaction emerged near the boundary between the dilute ethylene diamine tetraacetic acid and potassium iodide and highly concentrated KCl solutions. For the separation and concentration of three components, Cr 3+ , Cu 2+ , and Fe 3+ , the Fe 3+ detection limit was improved at least 266‐fold by comparing the hyphenated technique with moving reaction boundary electrophoresis. The detection limit of Fe 3+ was found to be as low as 0.34 ng (20 μM) on the paper chip. We also demonstrated the analysis of a real sample of four metal ions, with detection limits as follows: 0.16 μg Cr 3+ , 1.5 μg Ni 2+ , 0.64 μg Cu 2+ , and 1.5 μg Co 2+ . The synergy of field‐amplified sample stacking and moving reaction boundary electrophoresis in the micron paper‐based array channels dramatically improved the detection limit and throughput of paper‐based electrophoresis.