Product Certifications and Secondary Matrices
There are several agencies that evaluate mycotoxin detection test kits for performance against accuracy and precision criteria and issue an official Certification for the product test method. In the United States, the Agricultural Marketing Service Branch of the USDA (formerly known as GIPSA) oversees such certifications, the requirements of which include a manufacturer-provided data package demonstrating accuracy and robustness performance across three test kit lots, and additional independent testing of three kit lots at the USDA-FGIS evaluation lab. For any submission, the commodity of interest that represents the primary matrix must be tested using the mycotoxin naturally contaminated form of the commodity. This requirement ensures that the test accuracy represents the intended use of the product in the field and accurately represents the mycotoxin recovery from the test method’s extraction step.
Because the USDA thoroughly vets the test internally on the entire detection system (test procedure in combination with the detection and quantitation methods) and requires accuracy across a specified range of mycotoxin contamination of the primary matrix, the downstream test kit user is assured that the method is accurate and precise, providing the user with a trusted result within acceptable variation (allowable relative standard deviation, % RSD).
Additional commodities may also be submitted for certification but are dependent upon the primary matrix evaluation and approval to be considered certified under the umbrella of the test kit certification. Since the method performance was previously determined as sound using the primary matrix, additional matrices can be evaluated using mycotoxin fortification as opposed to natural contamination. The USDA-FGIS lab considers performance results without running verification testing on secondary matrices unless the extraction protocol is different from the primary matrix, in which case, performance is verified. Rapid lateral flow devices can be highly kinetic in that they are sensitive to variations in flow rate. Because the composition of different commodities can vary greatly, these variations may impact flow rate, which in turn, can impact performance when interpreted using the standard curve established for the primary matrix; this is called a ‘matrix effect’. When a matrix effect is present, the results can still be in an acceptable range, as defined by a certification body, but a bias might exist, either high or low, depending on the direction of the matrix effect. Instead of accepting biased results that are in range for secondary matrices, EnviroLogix takes the extra step to re-center the performance for each group of similar matrixes to provide the best possible accuracy for all commodities. This is done by providing lot specific matrix group curves in the form of a multi-matrix barcode card (MMBC), allowing the end user to test secondary matrices with confidence.
The AOAC International standards organization also provides test method certifications through its Performance Tested Method (PTM) program and is recognized internationally for its accreditation of test kit methods. This PTM program follows a similar validation process as the USDA, however, a third-party laboratory is contracted for the independent lab evaluation portion. Many of our mycotoxin products are certified by both the AOAC International and the USDA-ARS. Visit our website for a complete listing of our product certifications.