Overview
ISO 7124:2023 specifies a validated liquid chromatography–tandem mass spectrometry (LC‑MS/MS) method for the determination of fipronil and its metabolites in eggs and egg products. The method covers target analytes including fipronil, fipronil‑desulfinyl, fipronil‑sulfide and fipronil‑sulfone, and defines sample preparation, cleanup, chromatographic and mass spectrometric conditions, identification criteria and quantification using an isotope internal standard (fipronil‑C6).
Key Topics and Technical Requirements
- Scope: Determination of fipronil and metabolites residues in eggs and egg products using LC‑MS/MS.
- Sample handling: Homogenization of representative samples (start from ≥1 kg), preparation instructions for fresh eggs and egg products, and storage at −20 °C to −16 °C.
- Extraction: Acetonitrile extraction with addition of salts (sodium chloride, anhydrous sodium sulfate) and internal standard.
- Cleanup: Dispersive solid‑phase extraction (d‑SPE) using PSA, C18 and anhydrous magnesium sulfate prior to filtration (0.22 µm).
- Chromatography: Phenyl column (2.1 × 100 mm, 1.7 µm or equivalent), gradient elution between ammonium acetate/formic acid aqueous phase and methanol, 35 °C column temperature, 0.4 ml/min flow, 2 µl injection.
- Mass spectrometry: Electrospray ionization in negative polarity, multiple reaction monitoring (MRM) transitions specified for each analyte, with MS source and gas settings provided.
- Quantification & ID criteria: Internal standard calibration (fipronil‑C6), retention time match tolerance ±2.5%, confirmation by relative ion transition intensities, reporting in µg/kg.
- Standards & reagents: Reference to analytical grade solvents and reagents; standard materials with purity ≥95%; preparation and stability timelines for stock and working solutions.
- Performance: Procedures for blank tests, determination, calculation, limit of quantification and precision (annexes include chromatograms and precision data).
Applications
- Regulatory monitoring of pesticide residues in eggs and egg products for food safety and compliance with maximum residue limits (MRLs).
- Routine quality control testing by food laboratories, contract testing services and egg producers’ QC departments.
- Surveillance and investigative testing after suspected contamination incidents involving fipronil.
- Method transfer, validation and interlaboratory studies in analytical chemistry and food safety research.
Who Should Use This Standard
- Food testing and accredited analytical laboratories performing LC‑MS/MS residue analysis.
- National food safety and regulatory authorities enforcing residue limits.
- Egg and egg‑product manufacturers and processors for internal monitoring.
- Instrument vendors and method developers implementing validated analytical workflows.
Related Standards
- ISO 3696 - Water for analytical laboratory use (referenced for grade‑1 water).
- CAC/GL 50‑2004 - Recommended sampling guidance for foods (sampling recommendations referenced; sampling itself is not part of ISO 7124:2023).
For implementation, obtain the full ISO 7124:2023 standard from ISO or your national standards body to access complete procedural details, tables (MRM transitions, gradients), annex figures and validation data.
Open preview (PDF)Eggs and egg products — Determination of fipronil and metabolites residues — Liquid chromatography tandem mass spectrometry method
