Tag: criminalistic laboratory

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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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 law enforcement at the roadside.  However, the D-L test is not specific for just THC.  Many other cannabinoids, including hemp-derived extracts such as CBD, will yield similar purple hues in the presence of the reagent. Of course, these extracts are not marijuana under Iowa law, but […]

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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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