Tag: DCI

Drug Charge Dismissed After GRL Challenges Marijuana Identification

GRL recently put its knowledge of drug identification procedures to the test in a case involving alleged THC vape liquid. Police seized a vape cart during a traffic stop.  Field testing of the liquid extract showed a positive color change indicating the possible presence of marijuana. Frequent readers of the GRL Law blog know that field testing can mistake CBD for marijuana.  We’ve discussed this phenomenon here. This is where things get interesting. Police didn’t send the cart to the state crime lab.  Instead, they sent it to a local department that employs an officer with training in marijuana identification.  […]

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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 and federal law. The drug identification section is now capable of performing semi-quantitative testing of plant material to determine the total THC amount.  The method of analysis mirrors that used by the federal Drug Enforcement Administration.  If the sample exceeds 0.3%, then the substance will […]

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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 material and oils. In the FAQ section of the Iowa Division of Criminal Investigation Criminalistic Laboratory – Drug Identification website (https://dps.iowa.gov/divisions/criminal-investigation/criminalistics-laboratory/drug-identification), testing for controlled substances includes: The net weight (weight of substance without packaging) of the substance is recorded prior to any sampling and then […]

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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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