Proficiency testing for event-specific quantification of genetically modified maize MON87427: Performance assessment...

Area of Science:

• Metrology
• Genetically Modified Organisms (GMOs)
• Quantitative Analysis

Background:

• The Asia Pacific Metrology Program and Accreditation Cooperation organized a proficiency testing (PT) program for quantifying genetically modified maize.
• Certified reference materials were used to ensure accuracy and metrological traceability in the Asia Pacific region.

Purpose of the Study:

• To enhance measurement accuracy and metrological traceability for genetically modified (GM) maize quantification in the Asia Pacific region.
• To evaluate participant performance in quantifying GM maize MON87427 using certified reference materials and traceable reference values.

Main Methods:

• A proficiency testing program was conducted using certified reference materials of genetically modified maize MON87427.
• Participants' results were evaluated against metrologically traceable PT reference values (PTRVs).
• Performance was assessed using z-scores and ζ-scores to identify quantification bias and uncertainty estimation issues.

Main Results:

• Consensus values from participants exceeded assigned values, suggesting systematic DNA extraction effects.
• Participant performance, particularly when evaluated by ζ-score, indicated a need for improvement in quantification bias investigation.
• The study highlighted discrepancies between consensus values and assigned values, impacting performance evaluation.

Conclusions:

• Metrologically traceable reference values are essential for reliable PT performance assessment, outperforming consensus values.
• Enhanced understanding of uncertainty estimation and quantification bias is necessary for laboratories analyzing GM content.
• The program underscored the importance of robust metrological practices in GMO analysis.