AOAC 2018 Methods

( l ) Micropipets .—Eppendorf Reference Series 100, 200, and 1000 μL or equivalent. C. Reagents and Supplies ( a ) Methanol (CH 3 OH) .—Formula weight (FW) 32.04 g/mol, CAS 67-56-1, HPLC grade. ( b ) Acetonitrile (C 2 H 3 N) .—FW 41.05 g/ml, CAS 1336-21-6, HPLC grade. ( c ) Ammonium formate (NH 4 HCO 2 ) .—FW 63.06 g/mol, CAS 540-69-2, HPLC grade. ( d ) Formic acid (HCO 2 H) .—FW 46.03 g/mol, CAS 64-18-6, HPLC grade. ( e ) Water (H 2 O) .—FW 18.01 g/mol, CAS 7732-18-5, submicron filtered, HPLC grade or equivalent. ( f ) Liquid nitrogen . D. Solutions ( a ) Reference standard diluent and dried sample extraction solvent .—Methanol–water (80 + 20, % v/v). ( b ) Extraction solvent for oils .—100% methanol. ( c ) Mobile phase A .—10 mM ammonium formate buffer, pH 3.60, filtered 0.2 µm. ( d ) Mobile phase B .—Acetonitrile, filtered 0.2 µm. E. Reference Standards Reference standard solutions at 1000 µg/mL for all 10 cannabinoids are available from Cerilliant Corp. (Round Rock, Texas, USA). Mixed standards are stable for up to 3 days at 4°C. ( a ) Working Stock Solution A .—Pipet 100 µL THC and 100 µL CBD into microcentrifuge tube. Dilute with 300 µL reference standard diluent and vortex to mix for 1:5 dilution of THC and CBD. ( b ) Working Stock Solution B .—Pipet 100 µL THCV and 100 µL CBG into a microcentrifuge tube. Vortex to mix for a 1:2 dilution of THCV and CBG. ( c ) Working Stock Solution C .—Pipet 100 µL CBN and 100 µL CBC into a microcentrifuge tube. Vortex to mix for a 1:2 dilution of CBN and CBC.

AOAC Official Method 2018.10 Cannabinoid in Dried Flowers and Oil Liquid Chromatographic Method First Action 2018

[Applicable to the determination of 10 cannabinoids: tetrahydrocannabinolic acid (THCA), Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiolic acid (CBDA), cannabidiol (CBD), cannabigerolic acid (CBGA), cannabigerol (CBG), terahydrocannabivarin (THCV), cannabichromene (CBC), cannabinol (CBN), and cannabidivarinic acid (CBDVA) in cannabis dried flowers and oils.] A. Principle Samples are extracted with methanol–water (80 + 20) using sonication and vortex mixing. Samples are diluted prior to LC- UV analysis. Quantitation is performed with external calibration against reference standards for THCA, THC, CBDA, CBD, CBGA, CBG, THCV, CBC, CBN, and CBDVA. B. Apparatus ( a ) Analytical balanc e.—Sensitive to at least 0.0001 g. ( b ) Mortar and pestle . ( c ) Volumetric pipet .—Class A, 25 and 10 mL. ( d ) Centrifuge tubes .—Conical, amber polypropylene tubes, 50 mL. ( e ) Vortex mixer . ( f ) Centrifuge .—Benchtop with rotor for 50 mL conical tubes, maximum 21000 × g . ( g ) Ultrasonic bath . ( h ) LC system .—Agilent 1200 Series Liquid Chromatograph (Agilent, Mississauga, ON, Canada), equipped with binary pump and degasser, temperature-controlled column compartment, temperature-controlled autosampler, flow cell, 10 mm, 1.0 μL, 60 bar, diode array detection, ChemStation software, or equivalent HPLC system capable of operating up to 600 bar. ( i ) LC column .—Phenomenex Kinetex C18, 3.0 × 100 mm, 1.7 µm. ( j ) Microcentrifuge tubes .—Amber, 2 mL. ( k ) HPLC vials .—Amber, 2 mL.

Table 2018.10A. Preparation of mixed calibration standards Cannabinoid Std 1

Std 2

Std 3 Std 4 Std 5

Std 6

Std 7

THCA/CBDA

Dilution

NA a 250

NA 200 NA

NA 100

NA

μL

50

THC/CBD

Solution

NA

A

A

μL

50

40

100

50

THCV/CBG

Solution

B

B

μL

50

40

Std 1 100 μL

Std 3 100 μL

Std 4 100 μL

CBN/CBC

Solution

C

C

μL

50

40

CBDVA/CBGA

Solution

D

D

μL

50

40

CBN/CBC/CBG/THCV/CBDVA/CBGA

Solution

E

E

μL

100 600

50

80% MeOH

150

320

800

900

900

900

a  NA = Using original 1000 µg/mL stock solutions for each individual standard.

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