Separation and stacking of iodine species from seafood using surfactant-coated multiwalled carbon nanotubes as a pseudo-stationary phase in capillary electrophoresis

• Published in: Mikrochimica acta (1966) Vol. 183; no. 8; pp. 2441 - 2447
• Main Authors: Xu, Jing-Jing, Chang, Yan-xu, Hao, Jie, An, Mingrui, Tan, Zhijing, Yang, Rui, Cao, Jun, Peng, Li-Qing
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.08.2016; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical Chemistry; Borates; Buffers; Capillary electrophoresis; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Electrophoresis; Iodine; Microengineering; Multi wall carbon nanotubes; Nanochemistry; Nanotechnology; Nanotubes; Original Paper; Plugs; Porphyra; Seafood; Separation; Stacking; Surface active agents; Surfactants; Thyroid hormones; Tetraiodothyronine; Diode array detection; Diiodothyronine; Iodate; Porphyra; MWCNTs; Triiodothyronine; Carbon nanomaterial; Diiodotyrosine; Kelp
• ISSN: 0026-3672; 1436-5073
• DOI: 10.1007/s00604-016-1892-6

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. Graphical Abstract Surfactant coated multi-walled carbon nanotubes were used as a pseudostationary phase to improve separation in iodine speciation. A highly sensitive stacking method was developed to enhance the detection sensitivity of iodine species. The CE method was then applied to the analysis of iodine species in kelp and porphyra.