AOAC 2018 Methods

AOAC Official Method 2018.11 Quantitation of Cannabinoids

in Cannabis Dried Plant Materials, Concentrates, and Oils Liquid Chromatography–Diode Array Detection Technique with Optional Mass Spectrometric Detection First Action 2018.11

(Applicable to quantification and identification of cannabidiol, cannabidiolic acid, cannabinol, ∆ 9 -tetrahydrocannabinol, tetrahydrocannabinolic acid, cannabichromene, cannabidivarinic acid, cannabigerol, cannabigerolic acid, cannabidivarin, Δ 8 - tetrahydrocannabinol, and tetrahydrocannabivarin.) Caution : See Appendix B : Laboratory Safety. Use appropriate personal protective equipment such as lab coat, safety glasses, rubber gloves, and a fume hood. Dispose of solvents and solutions according to federal, state, and local regulations. A. Principle Cannabinoids are isolated from the homogenized dried plant material using two repeated extractions with ethanol. Oils and concentrates, such as Cannabis resins and tinctures are dissolved using the same solvent. The extract aliquot is filtered, diluted with methanol and analyzed using LC with DAD-UV detection. Samples are quantified against standards of known concentration using a linear regression calibration function. Identification of cannabinoids is performed based on comparison of analyte retention times and UV spectra in the sample and reference standards. Optional high-confidence identification can be achieved by employing a mass spectrometer as a secondary detector. B. Apparatus (a) LC-DAD system. —1290 Infinity LC system (or an equivalent UHPLC system) with 1290 Infinity II Diode Array Detector FS (Agilent Technologies, Santa Clara, CA, USA). (b) HR MS/MS system (optional). —6560 Q-TOF LC/MS system (Agilent Technologies, Santa Clara, CA, USA) equipped with electrospray ionization (or an equivalent high resolution MS/MS) instrument.

(c) Analytical balances. —accurate to two- and four-decimal places. (d) Gilson positive displacements pipets. —assorted for 100-1000 µL. (e) Repeater pipet. —for 10 µL - 50-mL size tips. (f) Horizontal shaker. —shaking speed at least 250 rpm. (g) Vortex mixer. (h) Centrifuge. —Relative centrifugal force (rcf) at least 3000 g . (i) pH Meter. (j) Volumetric flasks. —Class A, glass, assorted sizes. (k) Laboratory glassware. —Class A, various. (l) Disposable polypropylene centrifuge tubes. —15 and 50 mL.

(m) Disposable plastic syringes. —3 mL. (n) Syringe filters. —PFTE, 0.22 µm. (o) Filter paper. —Grade 390.