Variability associated with analytical methods used to measure aflatoxin in agricultural commodities

Area of Science:

• Analytical Chemistry
• Food Safety
• Mycotoxicology

Background:

• Accurate mycotoxin quantification is crucial for agricultural commodity safety.
• Method performance studies provide essential data on analytical precision.
• Understanding variability sources aids in optimizing testing protocols.

Purpose of the Study:

• To analyze analytical precision estimates for mycotoxin testing.
• To investigate the relationship between variance and aflatoxin concentration.
• To compare precision across different analytical methods and commodities.

Main Methods:

• Compiled 1019 precision estimates from mycotoxin method-performance studies (pre-1991).
• Sorted data by variance measurement, analytical method (TLC, LC, ELISA), and commodity.
• Applied regression analysis to model variance as a function of aflatoxin concentration (V=aCb).

Main Results:

• Variance generally increased with aflatoxin concentration, described by a power function.
• Liquid chromatography (LC) exhibited the lowest analytical variability; ELISA showed the highest.
• Among-laboratories variability was approximately double the within-laboratory variability for a given method.

Conclusions:

• Analytical variability in mycotoxin testing is concentration-dependent.
• Method choice significantly impacts precision, with LC being most precise and ELISA least.
• These findings, combined with sampling/preparation variability, inform overall test performance assessment for aflatoxin inspection.