A QuEChERS-Based Sample Preparation Method for the Analysis of 5-Nitroimidazoles in Bovine Milk by HPLC-DAD

J AOAC Int. 2017 Nov 1;100(6):1671-1680. doi: 10.5740/jaoacint.17-0213. Epub 2017 Jul 13.

Abstract

In this study, a simple, cost-effective, and sensitive HPLC diode-array detection method was developed for the simultaneous determination of six different 5-nitroimidazoles [metronidazole, 2-hydroxymethyl-1-methyl-5-nitro-1H-imidazole, dimetridazole (DMZ), ronidazole, ornidazole, and ipronidazole] in bovine milk samples. A QuEChERS-based sample preparation procedure was optimized by evaluating different cleanup sorbents, including zirconium-based sorbents (Z-Sep and Z-Sep+), C18, and primary-secondary amine (PSA), as well as EMR-Lipid cleanup solution. Acceptable analytical performance for all analytes was observed with recoveries in the range of 45-93% and RSDs of less than 15%. Negligible matrix interference was observed for most of the analytes due to application of PSA sorbent in a dispersive solid-phase extraction cleanup step. Method LOQs (mLOQs) for five of the six investigated analytes were set at a satisfactory low food product value of 2.5 ng/mL. For DMZ only, the mLOQ was set at 10 ng/mL. The procedure was evaluated through the analysis of 10 different natural samples.

MeSH terms

  • Animals
  • Cattle
  • Chromatography, High Pressure Liquid / methods*
  • Dimetridazole / analysis
  • Food Analysis / methods*
  • Food Contamination / analysis
  • Liquid-Liquid Extraction / methods*
  • Metronidazole / analysis
  • Milk / chemistry*
  • Nitroimidazoles / analysis*
  • Reproducibility of Results
  • Ronidazole / analysis
  • Sensitivity and Specificity
  • Specimen Handling / methods

Substances

  • Nitroimidazoles
  • Metronidazole
  • Ronidazole
  • Dimetridazole
  • 4-nitroimidazole