Tag: GC-MS

THC Metabolites Detected in Urine Following Full-Spectrum CBD Use

The November 4, 2020 issue of JAMA Psychiatry published results from a recent study examining whether the use of full-spectrum CBD from legal hemp (< 0.30% Δ9-THC) would lead to positive urine test results for THC metabolites. It has been often assumed that hemp-derived cannabidiol products will test negative for urinary THC.  However, the study showed that half of subjects tested positive for carboxy-THC, an inactive metabolite of Δ9-THC, after four weeks of daily use.  Samples were initially screened through urine drug assays.  Positive screens were confirmed through gas chromatography-mass spectroscopy. The results suggest that individuals consistently using full-spectrum, hemp-derived […]

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Yes, Drug Testing Methods Can Mistake Hemp-Derived CBD for THC

I recently came across a little-known study published in the Journal of Analytical Toxicology that raises serious questions regarding whether the gold standard in forensic urine testing could mistake hemp-derived CBD for THC. Many laboratories include derivatization as a part of their sample preparation for analysis by gas chromatography – mass spectroscopy (GC-MS).  Derivatization is the process by which a compound is changed chemically so that it has properties that are more amenable to a particular analytical method.  Essentially, the new compound becomes more suitable for detection and analysis. Researchers discovered trifluoracetic anhydride (TFAA), a common derivatizing agent used in GC-MS […]

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