Tag: forensic drug testing

THC Levels Do Not Predict Driving Impairment

The February 5, 2021 issue of Traffic Injury Prevention published results from an Australian study assessing the relationship between THC levels and driving performance.   Volunteers consumed vaporized cannabis samples of varying potencies containing THC, CBD and a placebo.  Blood and saliva samples were collected 30 minutes after inhalation and 3.5 hours later.  Researchers evaluated driving […]

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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 […]

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New Hemp Testing for Total THC Requires 5 Grams

The Iowa Division of Criminal Investigation Criminalistics Laboratory recently updated its policies regarding Cannabis testing in light of the 2018 Farm Bill, S.F. 599 and H.F. 2581.  Under the new laws, cannabis containing less than 0.3% total THC (Δ9-THC + THCA) is considered hemp.  Hemp extracts, including CBD, are no longer controlled substances under state […]

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Problems with the Identification of CBD by Thin Layer Chromatography

Thin layer chromatography (TLC) is a well-known qualitative laboratory technique to separate, detect and identify plant material extracts that have been processed so they longer possess botanical characteristics that can be observed through macro and microscopic analysis.  This includes cannabis products like gummies, truffles, bars and other edibles, but also substances like tar, ground plant […]

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Common Police Field Test Mistakes CBD for Marijuana

Police have historically relied on the Duquénois-Levine (D-L) colorimetric field test to presumptively identify botanical material as Cannabis for the purpose of arresting a suspect for possession of marijuana. The reagent used in the D-L test reacts with a particular part of the THC molecule producing an intense violet color that is readily identifiable by […]

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THC Metabolites Remain in Blood for Extended Periods During Abstinence

According to data recently published in the journal Drug and Alcohol Dependence, THC remained detectable in blood at levels greater than 2.0 ng/ml during several days of abstinence. Investigators affiliated with the University of British Columbia reviewed the relevant literature assessing residual THC plasma levels in those who regularly consume cannabis.  They reported: “[I]n all […]

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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 […]

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