MINTOTA Research Group, Departament de Química Analítica, Facultat de Química, Universitat de València, Dr. Moliner 50, 46100, Burjassot, València, Spain.
Anal Bioanal Chem. 2019 Apr;411(10):2141-2148. doi: 10.1007/s00216-019-01644-1. Epub 2019 Feb 23.
The Marquis test is the most frequently used spot color assay for the screening of unknown drugs such as amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-metilenedioxymethamphetamine, and morphine. However, this test involves the use of the toxic reagent formaldehyde, as well as the manipulation of concentrated sulfuric acid. Here, we report a new format of this test that improves the sustainability and safety for the operator by immobilizing formaldehyde into a polydimetylsiloxane composite. In contact with a solution (or suspension) of the suspected sample in sulfuric acid, the dispositive delivers formaldehyde and the reaction takes place in a few seconds. Under the proposed conditions, only small amounts of the drug (μg) are necessary to produce intense changes of color. In addition, the percentage of the drug in the sample can be established by obtaining pictures of the test vials and subsequent analysis of the digitalized images. The responses were linear for amphetamine-like drugs up to a concentration of 100 mg L, and the precision achieved was adequate (relative standard deviations, RSDs < 10%). The developed composites were tested for the determination of MDMA in several drug street samples, and a good correlation with the results obtained by a reference method based on liquid chromatography was found. The main advantages of the proposed approach over the traditional Marquis test format are better portability and safety for the operator at a lower cost and the possibility of using it for quantitative analysis.
马奎斯检测法是一种常用于筛查安非他命、甲基苯丙胺、3,4-亚甲二氧基苯丙胺、3,4-亚甲二氧基甲基苯丙胺和吗啡等未知药物的比色检测法。然而，这种检测法涉及使用有毒试剂甲醛以及浓流酸的操作。在此，我们报告了一种新的马奎斯检测格式，通过将甲醛固定在聚二甲基硅氧烷复合材料中，提高了其可持续性和操作人员的安全性。当与含有可疑样品的硫酸溶液（或悬浮液）接触时，该装置会释放甲醛，反应在几秒钟内发生。在提出的条件下，只需少量的药物（μg）就可以产生强烈的颜色变化。此外，通过获取测试小瓶的照片并对数字化图像进行后续分析，可以确定样品中药物的百分比。在 100 mg/L 浓度范围内，对安非他命类药物的响应呈线性，且精密度达到要求（相对标准偏差，RSDs < 10%）。所开发的复合材料已用于几种街头毒品样本中 MDMA 的测定，并且与基于液相色谱的参考方法的结果具有良好的相关性。与传统的马奎斯检测格式相比，该方法的主要优点是更好的便携性和操作人员的安全性，成本更低，并且有可能进行定量分析。
