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

Abstract

For the US Food and Drug Administration's (FDA) mycotoxin program, the desired application of certified reference materials (CRMs) is primarily for validating methods for the determination of mycotoxins in foods and establishing metrological traceability of measurement results generated by such validated methods. The latter has been an important but insufficiently addressed challenge due to the lack of appropriate protocols and CRMs. Taking advantage of two recently available mycotoxin CRMs, OTAN‐1 and Standard Reference Material (SRM) 1565, a protocol was developed for systematically examining uncertainty and establishing metrological traceability of measurement results of ochratoxin A (OTA) in corn through a series of calibration operations using the two CRMs. Instrument and method calibrations were performed using OTAN‐1 and SRM 1565. The OTA value and its standard and expanded (k = 2, approximately 95% confidence) uncertainties were estimated from the calibration data and documented. These results demonstrate that the major contributing source of uncertainty is the sample matrix, highlighting the important role of the certified matrix reference material in method calibration. The value of OTA (38.5 ± 7.2 µg/g; 95% confidence interval) in the incurred sample was metrologically traceable to the International System of Units through two CRMs using the multi‐laboratory validated liquid chromatography–mass spectrometry FDA compendial method. In addition, an alternative estimation of uncertainty was conducted using a one‐point calibration, resulting in comparable uncertainty.

Challenges and Future State for Mycotoxin Analysis: A Review From a Regulatory Perspective

“…38,39 As the landscape of mycotoxin analysis advances at the FDA, CRMs and QC samples must evolve to align with the method performance for the simultaneous detection of multiple mycotoxins using LC-MS. Multimycotoxin CRMs offer numerous advantages, including their suitability for proficiency testing, the creation of quality control charts, long-term method performance monitoring, establishment of metrological traceability, and the estimation of measurement uncertainty. 40,41 These advantages are of importance for the FDA field laboratories engaged in mycotoxin analyses of regulatory samples, where performance metrics such accuracy and precision are imperative. Such advantages are not readily attainable when relying solely on inhouse QC samples.…”

“…However, when in-house QC samples lack full characterization, they fall short in providing critical information concerning accuracy, precision, traceability, and uncertainty, potentially introducing errors into the process. − CRMs are well-characterized materials with known mycotoxin concentrations and established traceability and can serve as a reliable reference for demonstrating the qualitative and quantitative performance of FDA’s analytical methods. Although some CRMs have been incorporated into method development and routine sample analysis by the FDA, most of the available matrix CRMs were developed for single-mycotoxin analysis. , As the landscape of mycotoxin analysis advances at the FDA, CRMs and QC samples must evolve to align with the method performance for the simultaneous detection of multiple mycotoxins using LC-MS. Multimycotoxin CRMs offer numerous advantages, including their suitability for proficiency testing, the creation of quality control charts, long-term method performance monitoring, establishment of metrological traceability, and the estimation of measurement uncertainty. , These advantages are of importance for the FDA field laboratories engaged in mycotoxin analyses of regulatory samples, where performance metrics such accuracy and precision are imperative. Such advantages are not readily attainable when relying solely on in-house QC samples.…”

“…They serve as critical tools for calibration, validation, ongoing quality control, and ensuring the accuracy and traceability of the results. Incorporating CRMs into the analytical process enhances the reliability of mycotoxin measurements and supports regulatory compliance when necessary. , The development and production of a mycotoxin CRM, especially a matrix-based multimycotoxin CRM (e.g., NIST SRM 1565) takes 2–3 years, and requires long-term planning, collaboration, and resource commitment. The strategic partnership between the FDA and the NIST to leverage and engage academia, government, and private laboratories is a critical component of the development and evaluation of CRMs.…”