小型化离子阱质谱仪在毒品快速采集与分析中的应用

本研究设计并搭建了一台尺寸与行李箱相当，质量仅30 kg的小型化离子阱质谱仪。由于毒品的饱和蒸汽压较低，该仪器以热解吸和载气载带的方式实现毒品样品的进样，以10.6 eV低压氪灯为电离源，以矩形离子阱作为质量分析器对毒品样品进行检测。通过串联质谱(MS/MS)分析，同时用母离子和碎片离子对毒品进行定性，提高了毒品检测的准确性。本研究共测试了8种毒品样品，包括4种麻醉药品和4种精神类药品。它们的特征离子均为质子化的准分子离子［M+H］⁺，分析时间为2 min，检出限可达pg量级，MS/MS分析可卡因等毒品可同时得到样品的准分子离子和特征碎片离子信息。该小型化离子阱质谱仪不仅体积小、质量轻，而且灵敏度高、分析速度快、检测准确性高，有望成为未来毒品现场快速检测的有力工具。

Application of Portable Ion Trap Mass Spectrometer in Rapid Detection and Analysis of Illegal Drugs

The spread of narcotics has become one of the most serious problems of modern society, and a lot of studies were focused on the on-site inspection methods of illegal drugs. A high sensitivity, effective and less time-consuming, accurate and easy-to-operate method to detect illegal drugs for on-site operation was developed in the study. A miniaturized rectilinear ion trap mass spectrometer (RITMS) was designed and constructed, which was the equivalent size as a suitcase and weight less than 30 kg. As the characteristics of low saturation steam and high gasification temperature of the drugs, this miniaturized RITMS sample the drug samples by thermal desorber and gas carrier. And it was composed by a low pressure krypton lamp in 10.6 eV energy as a ionization source, a discontinuous atmospheric pressure interface (DAPI) and a rectilinear ion trap as a mass analyzer. The accuracy of the drug detection was improved by using tandem mass spectrometry through which the qualitative analysis of drugs was carried out using both parent ions and characteristic fragment ions. And the parameters of the instrument were optimized, including the desorber temperature, the flow rate of carrier gas, the time sequence of analysis and cooling, and the voltage of electron multiplier and some others. The results show that 8 different common illegal drugs were detected, including 4 narcotic and 4 psychotropic drugs. Their characteristic ions were all protonated quasi-molecular ions ［M+H］⁺, and the analysis time was 2 min. The limits of detection (LODs) of the drugs were at picogram level. And the quasi molecular ions and characteristic fragment ions of cocaine could be gotten from MS/MS analysis at the same time. The precision of the detection was controlled at about 20% at picogram sample volume. Compared to mass spectrometer for laboratory use and the on-site inspection instruments in use, the miniaturized RITMS has many advantages. Because of the thermal desorption sampler, the ambient ionization source and discontinuous atmospheric pressure interface, it can be used for drug detection without complex pretreatment of samples. And its small volume, light weight, high sensitivity, and fast analysis speed all make it obviously superior for on-site use. And the accuracy of drug detection is greatly improved through the inherent tandem MS capability. It is expected to become a powerful weapon for rapid on-site detection of illegal drugs in the future.