Food Analytical Methods

, Volume 12, Issue 10, pp 2139–2149 | Cite as

Determination of Iodine Species in Seafood by Ionic Liquid–Based In-line Solid-Phase Extraction-Capillary Electrophoresis

  • Shuling Wang
  • Tian XieEmail author
  • Xueman Dong
  • Jindong Hu
  • Lianhui Men
  • Jun CaoEmail author


Ionic liquid (IL)–based in-line solid-phase extraction (SPE)-capillary electrophoresis (CE) method was developed for determination of three iodine species (3,5-diiodo-l-thyronine, l-tyrosine, 3,5-diiodo-l-tyrosine) in seafood. The background electrolyte (BGE) used was 5 mM sodium tetraborate. The small SPE extractor filled with Oasis HLB sorbent was constructed and embedded 7.5 cm away from the entrance to the capillary, then the ILs were used as eluting solvents to elute analytes and separate the target compounds to improve the detection sensitivity in CE. Several parameters including the elution solvent, the elution time, pH of sample solution, and sample loading time were investigated. The LODs were 0.48 ng/mL for 3,5-diiodo-l-thyronine, 4.7 ng/mL for l-tyrosine, and 5.2 ng/mL for 3,5-diiodo-l-tyrosine under optimal experimental conditions. Compared with normal hydrodynamic injection, sensitivity enrichment factors for this enrichment strategy ranged from 11 to 9635. The in-line SPE-CE method was then applied to analyze kelp and seaweed samples, and the recoveries ranged from 87 to 117%.


Analyte concentrator Capillary electrophoresis In-line solid-phase extraction Ionic liquid Iodine species Seafood 



This study was funded by the Natural Science Foundation of Zhejiang Province, China (LY16H270018); the Key projects of National Natural Science Foundation of China (81730108); the Key Project of Zhejiang province Ministry of Science and Technology (2015C03055); the Key Project of Hangzhou Ministry of Science and Technology (20162013A07, 20142013A63); the Key Laboratory of Elemene Class Anti-cancer Chinese Medicine of Zhejiang Province; and the Engineering Laboratory of Development and Application of Traditional Chinese Medicine from Zhejiang Province.

Compliance with Ethical Standards

Informed Consent

Not applicable.

Conflict of Interest

Shuling Wang declares that she has no conflict of interest. Tian Xie declares that he has no conflict of interest. Xueman Dong declares that he has no conflict of interest. Jindong Hu declares that he has no conflict of interest. Lianhui Men declares that he has no conflict of interest. Jun Cao declares that he has no conflict of interest.

Ethical Approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Supplementary material

12161_2019_1553_MOESM1_ESM.docx (520 kb)
ESM 1 (DOCX 520 kb)


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Copyright information

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Medical CollegeHangzhou Normal UniversityHangzhouPeople’s Republic of China
  2. 2.College of Material Chemistry and Chemical EngineeringHangzhou Normal UniversityHangzhouPeople’s Republic of China

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