Marijuana and the Cannabinoids

192
Table 2
Published Methods for Mass Spectrometric Analysis of Cannabinoids in Plasma or Serum
LOQ LOD
Ref. Analyte Extraction Derivatization Instrumentation Ionization (ng/mL) (ng/mL) Notes
38 Multiple analytes Liq/Liq BSTFA GC/MS EI — 0.6 THC, CBD, DBN, and 5
metabolites of THC
76 THC and HO-THC Liq/Liq TFAA GC/MS NCl 0.2/0.5 — THCA analyzed using
different
derivatization
THCA 1. BF 3 /MeOH 0.2 — Early use of negative ion
2. TFAA chemical ionization
48 THC, HO-THC, SPE Methyl iodide GC/MS EI 0.6/0.7 3.4 — Improved version of an
and THCA
earlier assay
82 THC, THCA, and SPE PFBBr GC/MS NCl 0.3/0.3 — Extractive alkylation
HO-THC BSTFA 1.0 using XAD-2 resin
49 THC and THCA SPE TFAA and HFIP GC/MS NCL 0.5/2.5 — Fully validated assay
8 THC and major See notes BSTFA GC/MS EI — 0.5–2.5 Hydrolysis with
metabolites
β-glucuronidase;
extraction with an
immunoaffinity resin;
also analyzed
meconium
77 THC, HO-THC, SPE MSTFA GC/MS/MS EI 2/5/8 — Blood diluted 6:1
and THCA
prior to extraction
42 THC, HO-THC, SPE BSTFA GC/MS PCl 0.5/0.5 1.0 — Plasma hydrolyzed with
and THCA
β-glucuronidase.
Compares
concentrations with
and without
hydrolysis
50 THC and HO-THC SPE Tri-Sil TBT a GC/MS/MS PCl 0.05/0.1 0.01/0.2 Run time, 7 min
LOQ, limit of quantitation; LOD, lower limit of detection; Liq/Liq, liquid/liquid extraction; BSTFA, bis-(trimethylsilyl)-trifluoroacetamide; GC/MS, gas
chromatography/mass spectrometry; EI, electron ionization; THC, ∆ 9 -tetrahydrocannabinol; HO-THC, 11-hydroxy-∆ 9 -tetrahydrocannabinol; TFAA,
trifluoroacetic anhydride; NCI, negative ion chemical ionization; THCA, 11-nor-9-carboxy-∆ 9 -tetrahydrocannabinol; SPE, solid-phase extraction; HFIP,
hexafluoroisopropanol; MSTFA, N-methyl-N-(trimethylsilyl)-trifluoroacetamide; PCI, positive ion chemical ionization.
a
Tri-Sil TBT from Pierce Chemical Co., Rockford, IL.
192 Foltz