Virginia Commonwealth University, Richmond, VA, USA.
Virginia Department of Forensic Science, Richmond, VA, USA.
J Forensic Sci. 2021 Jan;66(1):285-294. doi: 10.1111/1556-4029.14562. Epub 2020 Sep 21.
The analysis of cannabis plant material submitted to seized-drug laboratories was significantly affected by the signing of the Agricultural Improvement Act of 2018, which defined hemp and removed it from the definition of marijuana in the Controlled Substances Act. As a result, field law enforcement personnel and forensic laboratories now are in need of implementing new protocols that can distinguish between marijuana-type and hemp-type cannabis. Colorimetric tests provide a cost-effective and efficient manner to presumptively identify materials prior to submission to a laboratory for analysis. This work presents the validation of the 4-aminophenol (4-AP) color test and demonstrates its utility for discriminating between marijuana-type and hemp-type cannabis (i.e., typification). Validation studies included the testing of numerous cannabinoid reference materials, household herbs, previously characterized cannabis plant samples, and real-case samples. The 4-AP test reliably produces a pink result when the level of Δ -tetrahydrocannabinol (THC) is approximately three times lower than the level of cannabidiol (CBD). A blue result is generated when the level of THC is approximately three times higher than that of CBD. Inconclusive results are observed when the levels of THC and CBD are within a factor of three from each other, demonstrating the limitations of the test under those scenarios.
提交给缉毒实验室的大麻植物材料的分析受到 2018 年《农业改进法案》签署的显著影响，该法案定义了大麻，并将其从《受控物质法案》中对大麻的定义中删除。因此，现场执法人员和法医实验室现在需要实施新的协议，以区分大麻型和大麻型大麻。比色测试提供了一种经济高效且有效的方法，可以在将材料提交实验室进行分析之前进行初步鉴定。这项工作验证了 4-氨基酚（4-AP）比色测试，并展示了其用于区分大麻型和大麻型大麻（即定型）的效用。验证研究包括测试多种大麻素参考物质、家用草药、以前表征的大麻植物样本和实际案例样本。当 Δ-四氢大麻酚（THC）的水平大约是大麻二酚（CBD）水平的三倍低时，4-AP 测试可靠地产生粉红色结果。当 THC 的水平大约是 CBD 的三倍高时，会产生蓝色结果。当 THC 和 CBD 的水平彼此相差三倍以内时，会观察到不确定的结果，表明在这些情况下测试存在局限性。
