Validation of a QuEChERS–UHPLC–MS/MS method for the determination of aflatoxins and ochratoxin A in cannabis flowers: Application to regulated and non-regulated products
Method validation study reveals aflatoxin contamination exceeding safety limits in non-regulated cannabis flowers, highlighting the critical need for routine quality control.
Key Points
Optimize and validate a QuEChERS–UHPLC–MS/MS method to simultaneously detect and quantify aflatoxins B1, B2, G1, G2, and ochratoxin A in Cannabis sativa flowers.
Optimized extraction parameters using a 3³ factorial design evaluating solvent acidification (acetonitrile with 0.1% v/v formic acid), extraction time (15 min vortex), and evaporation temperature (<50 °C).
Screened 30 regulated and non-regulated Cannabis sativa flower samples for mycotoxin contamination using the validated UHPLC–MS/MS protocol.
Demonstrated method recoveries between 90% and 109%, precision with RSDs of 2.5% to 8.3%, linearity R² > 0.99, and LOQs of 1.0 µg/kg for aflatoxins and 5.0 µg/kg for ochratoxin A.
All commercial cannabis samples complied with international maximum residue limits, while several non-regulated samples exceeded the 4 µg/kg total aflatoxin limit due to high aflatoxin B2 levels.