Research On The Doping Detection Technology Of Several Drugs By Ion Mobility Spectroscopy

Drug abuse seriously harms human physical and mental health and causes a series of social security problems,which has become a topic of global common concern.Rapid and highly sensitive on-site detection of drugs is of great significance to drug control,crack down on drug crimes and forensic medicine.Drug detection technology research has become a very important research field.Ion mobility spectrometry（IMS）detection technology has the characteristics of fast detection speed,low cost,high sensitivity and easy to operate.It has been widely used in the field of drug detection.However,in practical application,IMS only relies on the drift time to identify substances.For substances with similar drift time,the recognition rate is not high and false positives are easy to occur.In this paper,in view of the false positive phenomenon that IMS has insufficient selectivity in drug detection,using the custom-build Corona discharge ion mobility spectrometry（CD-IMS）in the laboratory,the ion mobility spectrometry doping technology was developed.Studies on doping detection of several common drugs including methamphetamine,morphine,meperidine and sufentanil have been carried out,mainly including:Using pyridine as dopant,a new technology of highly sensitive detection of Methamphetamine（MA）in the presence of nicotine was developed to eliminate the interference of nicotine on Methamphetamine detection.In the routine detection of MA by IMS,the ion mobility spectrum signal peaks of nicotine and MA are close to each other.IMS is difficult to resolve the ion signals of nicotine and MA,so it is difficult to resolve the ion signals of nicotine and MA effectively,which limits the wide application of IMS in the field detection of MA.In this paper,a detection method using pyridine as dopant is proposed.By changing the reaction ions of IMS,the mobility of the product ions of MA and nicotine is changed to varying degrees,so that the ion peaks overlapping with each other when hydration ions are used as reaction ions are separated.In order to optimize the parameters of the IMS and achieve the best detection effect of MA and nicotine,the influence of the temperature of the drift tube and the concentration of pyridine doping on the detection of MA in the presence of nicotine was experimentally studied.The results show that the detection limit of MA is about 0.5 ng with pyridine doping.The study also assessed the effect of different nicotine levels on MA detection and tested the effect of MA detection in oral fluid samples.The effectiveness and feasibility of the pyridine doping method were verified.Using ammonia as dopant,three common anesthetics,meperidine,morphine and sufentanil,were detected and analyzed.Meperidine,morphine and sufentanil are three commonly used narcotics in clinical practice.Although they have been listed as controlled drugs in China,compared with other drugs,they are easier to obtain and more likely to be abused into drugs.In this paper,IMS was used to detect and analyze these three anesthetic agents.It was found that morphine had two ionic signal peaks of[M]H⁺and[M-H₂O]⁺when hydronium ion was used as reaction ion,and the signal peak of[M-OH]⁺overlaps with the signal peak of meperidine,affecting the detection effect of the two,while the mobility of sufentanil was significantly different from that of the former two.Tests were not affected.In this paper,a method for detecting meperidine,morphine and sufentanil with ammonia as dopant was proposed.The high proton affinity of ammonia（854k J/mol）was used to suppress the production of morphine[MH]⁺and eliminate the signal peak overlap with meperidine.From the Angle of detection sensitivity and resolution,the influence of the temperature of the moving tube on the detection of meperidine,morphine and sufentanil was analyzed.The detection limits of meperidine,morphine and sufentanil were 0.017 ng,0.58 ng and 0.62 ng,respectively,for three kinds of anesthetic with different concentrations.The signal response of the mixed samples of three kinds of anesthetics was continuously monitored and the competitive ionization process among the three kinds of anesthetics was analyzed.