Anal Chem. 2015;87(10):5444-50. doi: 10.1021/acs.analchem.5b01060.
A novel test sample for the spatially resolved quantification of illicit drugs on the surface of a fingerprint using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and desorption electrospray ionization mass spectrometry (DESI-MS) was demonstrated. Calibration curves relating the signal intensity to the amount of drug deposited on the surface were generated from inkjet-printed arrays of cocaine, methamphetamine, and heroin with a deposited-mass ranging nominally from 10 pg to 50 ng per spot. These curves were used to construct concentration maps that visualized the spatial distribution of the drugs on top of a fingerprint, as well as being able to quantify the amount of drugs in a given area within the map. For the drugs on the fingerprint on silicon, ToF-SIMS showed great success, as it was able to generate concentration maps of all three drugs. On the fingerprint on paper, only the concentration map of cocaine could be constructed using ToF-SIMS and DESI-MS, as the signals of methamphetamine and heroin were completely suppressed by matrix and substrate effects. Spatially resolved quantification of illicit drugs using imaging mass spectrometry is possible, but the choice of substrates could significantly affect the results.
本研究展示了一种新颖的测试样本，可利用飞行时间二次离子质谱（ToF-SIMS）和解吸电喷雾电离质谱（DESI-MS）对指纹表面的非法药物进行空间分辨定量。从喷墨打印的可卡因、冰毒和海洛因阵列中生成了与沉积在表面上的药物量相关的信号强度校准曲线，沉积质量名义上在每个点为 10 pg 至 50 ng 之间。这些曲线用于构建浓度图，直观地显示了药物在指纹顶部的空间分布，并且能够在地图中的给定区域内定量药物的含量。对于硅上的指纹上的药物，ToF-SIMS 非常成功，因为它能够生成所有三种药物的浓度图。在纸上的指纹上，仅使用 ToF-SIMS 和 DESI-MS 构建了可卡因的浓度图，因为基质和基底效应完全抑制了冰毒和海洛因的信号。使用成像质谱对非法药物进行空间分辨定量是可行的，但基底的选择可能会显著影响结果。
