Ionic-liquid-based dispersive liquid-liquid microextraction for high-throughput multiple food contaminant screening

Yee Man Ho, Yeuk Ki Tsoi, Kelvin S Y LEUNG*

*Corresponding author for this work

Research output: Contribution to journalJournal articlepeer-review

25 Citations (Scopus)


This paper describes an innovation of dispersive liquid-liquid microextraction enabling multiple-component analysis of eight high-priority food contaminants in two chemically distinctive families: Sudan dyes and phthalate plasticizers. To provide convenient sample handling for solid and solid-containing matrices, a modified dispersive liquid-liquid microextraction procedure used an extractant precoated frit to perform simultaneous filtration, solvent mixing, and phase dispersion in one simple step. A binary ionic liquid extractant system was carefully tuned to deliver high quality analysis based only on affordable LC with diode array detector instrumentation. The method is comprehensively validated for robust quantification with good precision (6.9-9.8% RSD) in a linear 2-1000 μg/L range. Having accomplished enrichment factors up to 451, the treatment enables sensitive detection at 0.09-1.01 μg/L levels. Analysis of six high-risk solid condiments and sauces further verified its practical applicability within a 70-120% recovery range. Compared to other approaches, the current dispersive liquid-liquid microextraction treatment offers major advantages in terms of minimal solvent (1.5 mL) and sample (0.1 g) consumption, ultra-high analytical throughput (6 min), and the ability to handle complex solid matrices. The idea of performing simultaneous analysis for multiple contaminants presented here fosters a more effective mode of operation in food control routines.

Original languageEnglish
Pages (from-to)3791-3798
Number of pages8
JournalJournal of Separation Science
Issue number23
Publication statusPublished - Dec 2013

Scopus Subject Areas

  • Analytical Chemistry
  • Filtration and Separation

User-Defined Keywords

  • Dispersive liquid-liquid microextraction
  • Food control
  • Ionic liquids
  • Phthalates
  • Sudan dyes


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