Sensing Precursors of Illegal Drugs-Rapid Detection of Acetic Anhydride Vapors at Trace Levels Using Photoionization Detection and Ion Mobility Spectrometry.

Victor Bocos-Bintintan,Aurel-Vasile Martiniuc,Ileana-Andreea Ratiu,Mircea Anton,George-Bogdan Ghira

doi:10.3390/molecules25081852

Victor Bocos-Bintintan, Aurel-Vasile Martiniuc + Show 3 more

Open Access

https://doi.org/10.3390/molecules25081852

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Abstract

Sensitive real-time detection of vapors produced by the precursors, reagents and solvents used in the illegal drugs manufacture represents a priority nowadays. Acetic anhydride (AA) is the key chemical used as acetylation agent in producing the illegal drugs heroin and methaqualone. This study was directed towards quick detection and quantification of AA in air, using two fast and very sensitive analytical techniques: photoionization detection (PID) and ion mobility spectrometry (IMS). Results obtained indicated that both PID and IMS can sense AA at ultra-trace levels in air, but while PID produces a non-selective response, IMS offers richer information. Ion mobility spectrometric response in the positive ion mode presented one product ion, at reduced ion mobility K0 of 1.89 cm2 V−1 s−1 (almost overlapped with positive reactant ion peak), while in the negative ion mode two well separated product ions, with K0 of 1.90 and 1.71 cm2 V−1 s−1, were noticed. Our study showed that by using a portable, commercial IMS system (model Mini IMS, I.U.T. GmbH Berlin) AA can be easily measured at concentrations of 0.05 ppmv (0.2 mg m−3) in negative ion mode. Best selectivity and sensitivity of the IMS response were therefore achieved in the negative operation mode.

Highlights

Illegal drugs are currently detected in a direct way, in real time, using commercial trace detectors, most of them based on ion mobility spectrometry (IMS); these IMS detectors are widely used worldwide, e.g., in all major airports, in governmental buildings, customs and so forth
Experimental data generated by the photoionization detector (PID) were gathered simultaneously with the data produced by the ion mobility spectrometer (IMS)
Ion mobility spectrometric responses from Acetic anhydride (AA) were obtained in both negative and positive ion modes, which constitute a real advantage for the identification of a target chemical—because very few compounds produce IMS responses in both ion modes

Summary

Introduction

Illegal drugs are currently detected in a direct way, in real time, using commercial trace detectors, most of them based on ion mobility spectrometry (IMS); these IMS detectors are widely used worldwide, e.g., in all major airports, in governmental buildings, customs and so forth. These instruments are quite bulky and have large power requirements. The reason for including acetic anhydride (AA) in the Table 1 of scheduled controlled substances is exactly its use, by drug manufacturers, as an acetylation agent in heroin production [12]. Its quantitation has great impact in protecting the health of the law-enforcement personnel that investigate a clandestine drug production facility

Results and Discussion

Materials and Methods

Schematic

PID Instrument Used

IMS Instrument Used