Development of analytical methodology for the detection of polar residues in food using LC-MS/MS

  • Clément Douillet

Student thesis: Doctoral ThesisDoctor of Philosophy


Research was carried out on influenza drugs that led to the development of a method for the analysis of 15 antiviral agents in poultry muscle by LC-MS/MS. The method developed included highly polar to non-polar analytes that were separated using a HILIC BEH Amide column. This method was validated following the new European Union guidelines 2021/808. 

Another LC-MS/MS method was developed for the confirmatory analysis of 15 broad spectrum antiviral drugs including ritonavir and metabolites in chicken, pork and prawn. Theses polar and non-polar analytes were extracted from muscle tissue samples with methanol prior to chromatographic separation on a Poroshell 120 Sb-Aq column. The method was also fully validated in agreement with guidelines 2021/808.
An analytical LC-MS/MS method for the detection of chlorate and perchlorate residues in milk was developed. A chromatographic method was optimised by employing a PFP reversed-phase column and acetonitrile extraction. The method was validated in accordance with SANTE/11813/2017 guidelines.

The introduction of the UniSpray source further improved the sensitivity of the method compared to electrospray. This sensitivity gain allowed the simplification of the sample preparation procedure and the concentration step was removed. This method was fully validated in milk and milk powder according to the same validation guidelines. 

Analytical strategies at different level were discussed across the optimisation of methods for the analysis of these three families of polar analytes. The UniSpray ionization source was observed to generally improve the detector signal of polar compounds but can only be used in specific application conditions. HILIC is required for highly polar analytes although reversed-phase is more suitable for high-throughput analysis because of the shorter equilibration periods required. In this work, it was found that simplified extraction procedures were required to allow the combined analysis of both high polar with polar to non-polar molecules.

Thesis embargoed until 31st July 2028
Date of AwardJul 2023
Original languageEnglish
Awarding Institution
  • Queen's University Belfast
SponsorsEC-Horizon 2020
SupervisorChristopher Elliott (Supervisor) & Martin Danaher (Supervisor)


  • Food safety
  • LC-MS/MS

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