Abstract
This article describes an on-line technique for hydrodynamic injections of long sample plugs with simultaneous stacking of iodine species in capillary electrophoresis (CE) with diode array detection. Surfactant-coated multi-walled carbon nanotubes (SC-MWNTs) were used as a pseudostationary phase for the separation of iodate, tetraiodothyronine,triiodothyronine, diiodothyronine, and diiodotyrosine. The effects of MWNTs, concentration of SC-MWNTs and salt, of buffer pH value, injection times were examined. Under the optimized conditions, i.e. detection at 230 nm, a separation voltage 25 kV, a borate running buffer of pH 7.5 and a SC-MWNT concentration of 9 μg · mL−1, the method gave relative standard deviations of the retention times and peak areas in intra-day assays (for n = 6) and for inter-day assays (for n = 3) of less than 4.49 and 5.80 %, respectively. The CE method was then applied to the analysis of the above iodine species in (spiked) kelp (kunbu) and porphyra, and recoveries ranged from 81.6 to 98.4 % with RSDs (n = 3) for extraction repeatability of <3.39 % in all cases.
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Acknowledgments
This study was supported by the National Natural Science Foundation of China (No. 81274065), the Zhejiang Provincial Natural Science Foundation of China (LY15H280016), the Hangzhou social development of scientific research projects (No. 20150533B05), Research on Public Welfare Technology Application Projects of Zhejiang Province (No. 2014C37069), Young and Middle-Aged Academic Leaders of Hangzhou (2013–45), and Changjiang Scholars and Innovative Research Team in Chinese University (IRT 1231).
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Xu, JJ., Chang, Yx., Hao, J. et al. Separation and stacking of iodine species from seafood using surfactant-coated multiwalled carbon nanotubes as a pseudo-stationary phase in capillary electrophoresis. Microchim Acta 183, 2441–2447 (2016). https://doi.org/10.1007/s00604-016-1892-6
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DOI: https://doi.org/10.1007/s00604-016-1892-6