Stojanovska Natasha, Tahtouh Mark, Kelly Tamsin, Beavis Alison, Fu Shanlin
Centre for Forensic Science, University of Technology, Sydney (UTS), PO Box 123, Broadway, NSW, 2000, Australia.
Australian Federal Police, 110 Goulburn St, Sydney, NSW, 2007, Australia.
Drug Test Anal. 2015 May;7(5):393-400. doi: 10.1002/dta.1684. Epub 2014 Jun 17.
Desorption electrospray ionization - mass spectrometry (DESI-MS) is a useful technique for the qualitative analysis of compounds found in seized drug material. In this study, DESI-MS was utilized in the screening analysis of illicit cocaine samples. The technique was also applied to the geographical origin determination of these samples. The limit of detection was determined to be 24.3 µg (or 3.47 µg/mm(2) ) and the analysis time was less than 1 minute per sample. The intra-day and inter-day precision for the detection of cocaine was 11 % and 42 %, respectively; therefore the quantitative data provided by DESI-MS was limited in its use for accurate determination of cocaine concentration in a sample. Using the quadrupole time-of-flight (QTOF) mass spectrometer, the presence of cocaine and impurities detected were confirmed by accurate tandem MS data. The qualitative chemical profiles obtained using DESI-MS were compared to two popular analysis techniques, GC-MS and LC-MS. The effects of a range of adulterants including caffeine, procaine, levamisole, lignocaine, paracetamol, and atropine on the detectability of cocaine were also investigated. It was found that the addition of these adulterants in a cocaine sample did not prevent the detection of the analyte itself (there was slight enhancement in some samples), which was useful in drug detection. The detection of truxillines in the seized samples by DESI-MS aided in the preliminary determination of geographical origin, i.e., Bolivian, Peruvian or Colombian leaf origin. The application of DESI-MS to the qualitative analysis and screening of seized cocaine samples demonstrates the potential and applicability of the technique to the fast chemical profiling of illicit samples.
解吸电喷雾电离质谱法（DESI-MS）是一种用于定性分析缴获毒品材料中化合物的有用技术。在本研究中，DESI-MS被用于非法可卡因样品的筛选分析。该技术还被应用于这些样品的地理来源确定。检测限确定为24.3微克（或3.47微克/毫米²），每个样品的分析时间少于1分钟。可卡因检测的日内和日间精密度分别为11%和42%；因此，DESI-MS提供的定量数据在准确测定样品中可卡因浓度方面的用途有限。使用四极杆飞行时间（QTOF）质谱仪，通过精确的串联质谱数据确认了检测到的可卡因和杂质的存在。将使用DESI-MS获得的定性化学图谱与两种常用分析技术GC-MS和LC-MS进行了比较。还研究了一系列掺杂物（包括咖啡因、普鲁卡因、左旋咪唑、利多卡因、对乙酰氨基酚和阿托品）对可卡因可检测性的影响。发现向可卡因样品中添加这些掺杂物并不会妨碍对分析物本身的检测（在某些样品中有轻微增强），这在毒品检测中很有用。通过DESI-MS检测缴获样品中的古柯碱有助于初步确定地理来源，即玻利维亚、秘鲁或哥伦比亚叶来源。DESI-MS在缴获可卡因样品的定性分析和筛选中的应用证明了该技术在非法样品快速化学图谱分析方面的潜力和适用性。
