MINTOTA Research Group, Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, Dr. Moliner 50, 46100 Burjassot, Valencia, Spain.
Molecules. 2018 Sep 15;23(9):2359. doi: 10.3390/molecules23092359.
Because of its inherent qualities, in-tube solid-phase microextraction (IT-SPME) coupled on-line to nanoliquid chromatography (nanoLC) can be a very powerful tool to address the new challenges of analytical laboratories such as the analysis of traces of complex samples. This is the case of the detection of contact traces of drugs, especially cannabis. The main difficulties encountered in the analysis of traces of cannabis plants on surfaces are the low amount of sample available (typically < 1 mg), the complexity of the matrix, and the low percentages of cannabinoic compounds in the samples. In this work, a procedure is described for the detection of residues of cannabis on different surfaces based on the responses obtained by IT-SPME coupled to nanoLC with UV diode array detection (DAD) for the cannabinoids Δ⁸-tetrahydrocannabinol (THC), cannabidiol (CBD), and cannabinol (CBN); the proposed conditions can also be applied for quantitative purposes through the measurement of the percentage of THC, the most abundant cannabinoid in plants. The method is based on collecting the suspected drug samples with cotton swabs, followed by the extraction of the target compounds by ultrasound assisted extraction. The extracts are then separated and processed by IT-SPME-nanoLC. The proposed approach has been applied to the detection of traces of cannabis in different kind of items (plastic bags, office paper, aluminum foil, cotton cloths, and hand skin). Sample amounts as low as 0.08 mg have been collected and analysed for THC. The selectivity and effect of the storage conditions on the levels of THC have also been evaluated. The percentages of THC in the samples typically ranged from 0.6% to 2.8%, which means that amounts of this compound as low as 1⁻2 µg were adequately detected and quantified. For the first time, the reliability of IT-SPME-nanoLC for the analysis of complex matrices such as cannabis plant extracts has been demonstrated.
由于其固有特性，在线内固相微萃取（IT-SPME）与纳流液相色谱（nanoLC）相结合，可以成为分析实验室应对新挑战的非常有力的工具，例如分析复杂样品的痕量。这就是痕量检测药物接触痕迹的情况，特别是大麻。在分析表面上大麻植物的痕量时，主要遇到的困难是可用于分析的样品量低（通常<1mg）、基质的复杂性以及样品中大麻素化合物的低百分比。在这项工作中，描述了一种基于 IT-SPME 与 nanoLC 结合使用，通过紫外二极管阵列检测（DAD）对大麻素Δ⁸-四氢大麻酚（THC）、大麻二酚（CBD）和大麻醇（CBN）进行响应的方法，用于检测不同表面上的大麻残留物；通过测量 THC 的百分比，也可以应用这些条件进行定量分析，这是植物中最丰富的大麻素。该方法基于用棉签收集可疑药物样本，然后通过超声辅助提取提取目标化合物。然后通过 IT-SPME-nanoLC 分离和处理提取物。该方法已应用于不同物品（塑料袋、办公用纸、铝箔、棉布和手部皮肤）中大麻痕迹的检测。收集并分析了低至 0.08mg 的 THC 样品。还评估了储存条件对 THC 水平的选择性和影响。样品中 THC 的百分比通常在 0.6%至 2.8%之间，这意味着可以检测和定量到低至 1-2µg 的这种化合物。首次证明了 IT-SPME-nanoLC 用于分析大麻植物提取物等复杂基质的可靠性。
