Single-Laboratory Validation of an Immunoaffinity Column Cleanup LC Method for the Analysis of Aflatoxins and Ochratoxin A in Cannabis Plant Material, Resins, Vapes, Isolates and Edible Products

Potential fungal infection of cannabis plants during drying has raised concerns of resulting mycotoxin contamination in leaves and flowers and subsequent contamination of derived products including cannabis containing edible products. Validated routine methods are essential to monitor cannabis and cannabis products to ensure consumer safety consistent with long-standing controls for mycotoxins such as aflatoxins and ochratoxin A in foodstuffs. To provide single laboratory validation data to demonstrate the suitability of a method for determining aflatoxins and ochratoxin A in cannabis plant material, resins, vapes, isolates and edible products such as chocolate. Extraction of solid and liquid matrices with acetonitrile: water, centrifugation and then dilution of an aliquot of supernatant with phosphate buffered saline solution containing Tween 20 surfactant. Cleanup by passing through an immunoaffinity column containing antibodies to both aflatoxins and ochratoxin A and analyzing in a single LC chromatographic run with fluorescence detection. For within-day analysis, recoveries were in the range 77 to 99% with RSDs from 0.7 to 9.6% for aflatoxin B1. Similarly, ochratoxin A recoveries were from 64 to 94% and RSDs from 0.9 to 9.5% for mycotoxin mixtures spiked into cannabis flowers, resins, vapes, isolates, chocolate, gummies, edible oils and beverages. A multi-mycotoxin immunoaffinity column cleanup with LC-fluorescence has been validated and shown to be suitable for routine control of aflatoxins and ochratoxin A in cannabis flowers and a diverse range of edible cannabis products.