Ochratoxin A case study: Establish metrological traceability of mycotoxin measurements using certified reference...

Area of Science:

• Food safety analysis
• Analytical chemistry
• Metrology

Background:

• Certified Reference Materials (CRMs) are essential for validating mycotoxin determination methods and ensuring metrological traceability in food analysis.
• Establishing metrological traceability for mycotoxin measurements has been challenging due to a lack of appropriate protocols and CRMs.

Purpose of the Study:

• To develop and validate a protocol for establishing metrological traceability of ochratoxin A (OTA) measurements in corn using newly available mycotoxin CRMs.
• To systematically examine measurement uncertainty and its sources in OTA determination.

Main Methods:

• Utilized two mycotoxin CRMs, OTAN-1 and Standard Reference Material (SRM) 1565, for instrument and method calibration.
• Performed calibration operations to estimate OTA values and associated uncertainties (standard and expanded).
• Employed a multi-laboratory validated liquid chromatography-mass spectrometry (LC-MS) FDA compendial method.

Main Results:

• Developed a protocol for systematic uncertainty examination and metrological traceability establishment for OTA in corn.
• Identified the sample matrix as the major source of uncertainty in OTA determination.
• Achieved metrological traceability of OTA (38.5 ± 7.2 µg/g) in an incurred sample to the International System of Units.

Conclusions:

• The developed protocol effectively establishes metrological traceability for OTA in corn using available CRMs.
• Certified matrix reference materials play a critical role in accurate method calibration and uncertainty assessment.
• Alternative uncertainty estimation using one-point calibration yielded comparable results.