Department of Applied Sciences, Faculty of Health and Applied Sciences, University of the West of England, Bristol, UK.
J Forensic Sci. 2022 Jul;67(4):1697-1703. doi: 10.1111/1556-4029.15042. Epub 2022 Apr 3.
Gamma-hydroxybutyrate (GBH) is a popular recreational drug. Its strong sedative and amnesic effects have led to drug-facilitated sexual assaults, poisonings, overdose, and death. As a result, legislation has restricted its availability leading to GHB, consumers switching to its pro-drug, gamma-butyrolactone (GBL). Consequently, there is a growing need for methods capable of their determination in complex samples such as beverages. Previous studies have shown the possibility to colorimetrically qualitatively determine both GBH and GBL by the formation of the lactone and its reaction with hydroxylamine and ferric chloride to give a purple-colored complex. In this present investigation, we have shown the possibility of using this approach to both quantify GBL and GHB using both UV/Vis spectrometry and by the application of the camera of a smartphone to record images of the purple color developed. Via subsequent use of a downloadable free App, to extract the numerical values of the Red, Green, and Blue (RGB) color components, it was shown possible to construct a calibration curve and to quantitatively determine the concentration of the drugs present in fortified alcoholic beverage samples. It was found that by simple mathematical normalization of the RGB values the effects of camera distance and elimination could be readily overcome. Using the smartphone approach, GBL determinations on a sample of lager beer gave a mean recovery of 103% (%CV = 0.70%, n = 5) at a concentration of 0.56 mg/ml indicating the method holds promise for the determination of GBL and GHB in such samples.
γ-羟基丁酸（GBH）是一种流行的消遣性药物。其强烈的镇静和健忘作用导致了药物辅助的性侵犯、中毒、过量和死亡。因此，立法限制了其供应，导致 GHB 消费者转而使用其前体药物γ-丁内酯（GBL）。因此，对于能够在饮料等复杂样品中测定它们的方法的需求不断增长。先前的研究表明，通过形成内酯及其与羟胺和氯化铁的反应，可以产生紫色复合物，从而可以通过比色法定性地确定 GBH 和 GBL。在本研究中，我们已经证明了使用这种方法通过紫外/可见光谱法和智能手机摄像头记录紫色显色图像来定量测定 GBL 和 GHB 的可能性。通过随后使用可下载的免费应用程序提取红色、绿色和蓝色（RGB）颜色分量的数值，可以构建校准曲线并定量测定强化酒精饮料样品中存在的药物浓度。结果发现，通过对 RGB 值进行简单的数学归一化，可以很容易地克服摄像头距离和消除的影响。使用智能手机方法，在拉格啤酒样品上进行 GBL 测定，在浓度为 0.56mg/ml 时的平均回收率为 103%（%CV=0.70%，n=5），表明该方法有望用于此类样品中 GBL 和 GHB 的测定。
