Technical means of drug detection.

Technical means of drug detection.

SIMONOV Evgeny Anatolyevich,
SOROKIN Vladimir Igorevich

TECHNICAL MEANS OF DRUG DETECTION

The article discusses methods of instrumental drug detection in non-laboratory conditions.

Data on equipment manufacturers and the performance characteristics of some models are summarized.

New models of drug testing devices, including domestically produced ones, are briefly described.

Technical systems for detecting drugs in non-laboratory conditions are designed to solve specific problems that require high productivity and speed of obtaining results or high sensitivity.

Under such conditions, generally accepted laboratory methods for expert examination of drugs are ineffective and are rarely used.

The technical means under consideration are usually developed to detect a limited list of substances, which includes the most commonly encountered drugs in illegal circulation: heroin, cocaine, marijuana, methadone, phencyclidine, amphetamines and LSD.

The tasks solved with the help of such equipment include:

• searching for drugs during searches of suspects, premises of various purposes, luggage, cars and other vehicles;
• searching for drugs at checkpoints during various events with a large gathering of people, for example, at customs, at public and sporting events, at airports, etc.;
• drug search at inspection points for trucks, rail, water or air transport;
• drug search in mail.

When selecting equipment, numerous factors must be taken into account, among which the following are of no small importance:

• the cost of the equipment, which can range from several hundred to several hundred thousand US dollars, sometimes more;
• the cost of equipment maintenance, which can vary greatly depending on the type of equipment;
• the capacity of the equipment, which means the number of people, cars or pieces of hand luggage examined in a certain time.

The latter indicator can be very critical when choosing equipment, since it determines the speed of the inspection.

For example, when inspecting a car in which drugs were transported, this indicator is of little significance.

In addition to the above, when choosing equipment, its portability, the ability to conduct in-depth research of individual areas of the objects being checked (for example, baggage), as well as the level of training of personnel for operation and maintenance, and others are of no small importance.

The analysis considered in this article involves the study of a complex of vapors and microparticles of a drug in the air or on various surfaces.

Under normal conditions and depending on the physical and chemical properties of the substance, the concentration of drug vapor in the air at equilibrium ranges from 200 ppm (one part per million) for methamphetamine to 1 ppt (one part per billion) for heroin and is highly dependent on ambient temperature. An increase in temperature by 5° C usually doubles the concentration of the substance in the air [1].

Microparticle contamination of various surfaces usually occurs through contact with the drug or with surfaces on which it is present.

The size of these microparticles usually ranges from several micrograms to several tens of micrograms.

As has been experimentally proven, 10-5 – 10-7 g of the substance gets on the hands of people who have had contact with the drug. It can then be transferred to other surfaces, such as clothing, door handles, and fittings.

The amount of the substance transferred depends on a large number of factors determined by the physicochemical properties of the drug, the nature of the donor and acceptor surfaces, the area of ​​contact between the surfaces, the force of their contact, etc. Removing particles from a contaminated surface requires considerable effort, for example, a single hand wash with soap reduces the amount of cocaine on them by only two orders of magnitude. However, even in this case, it can be reliably detected using standard methods.

The above defines two main methods of sampling for drug testing in non-laboratory conditions: sampling the vapor-gas phase on appropriate filters and removing microparticles from the surface with special swabs.

The first method collects vapors and microparticles of the substance being tested in the air by pumping it through filters, which are then placed in special devices where they are desorbed using temperature and/or air flow.

Some companies produce equipment that allows drug detection by directly pumping air into its sample receiving device.

The second method is designed to collect drug microparticles from various surfaces using special wipes, usually provided by the equipment manufacturer. To increase the amount of desorbed material, the wipes are moistened with an alcohol-water mixture. Then the resulting wash is transferred to the device. This method usually gives better results, since it allows you to take a more representative sample.

Table 1 summarizes some of the performance characteristics of the main methods for detecting drugs in non-laboratory conditions.

Table 1. Performance characteristics of methods for detecting drugs in non-laboratory conditions

Table 1 shows that a fairly large number of drug testing methods have been developed to date, allowing a specialist to choose the most appropriate approach to solving the problems facing him.

Table 2 contains data on specific models and their manufacturers, along with a brief indication of the areas of use of this equipment, as well as some other indicators.

Table 2. Some types of equipment, their indicators and areas of use

Table 2 shows that devices operating on the principle of ion mobility spectroscopy are currently widely used to study drugs.

Such devices allow analyzing low concentrations of not only drugs, but also explosives, and some models – even toxic substances. In this case, the analysis time is usually 10 – 20 s.

Photo 1. IONSCAN 400 drug detector

Photo 2. Drug detector SABRE 2000

Drug detector IONSCAN 400 (photo 1) of Barringer Technologies Inc. (Canada) at the request of the Standing Committee on Drug Control several years ago was tested at the State Institution Expert-Criminalistics Center of the Ministry of Internal Affairs of Russia and at the Institute of Criminalistics of the FSB of Russia.

As a result, it was established that this device can be successfully used in Russia for preliminary examination of a large number of objects for their relation to drugs or explosives. These conclusions were subsequently successfully confirmed in practice.

The SABRE 2000 device is a later modification of the IONSCAN 400. It is distinguished by its lower weight and a greater number of sampling methods.

However, compared to its predecessor, it has reduced sensitivity for almost all substances.

Photo 3. VaporTracer2 device

Photo 4. ItemiSer3 device

The devices of Ion Track Instruments (USA) operate on similar principles. Photos 3 and 4 show the latest developments of this company, which can be used in the same way as those discussed above.

ZAO SPETSPRIBOR (Tula) produces a drug detector for detecting small concentrations of drugs «SLED», which in its tactical and technical characteristics is not inferior to the device IONSCAN 400 of Barringer Technologies Inc. in a number of indicators. So we can expect the appearance of domestic devices in the future that can meet the needs of law enforcement agencies for this type of equipment.

Another promising domestic development is the GHMS device, created at the Design and Technology Institute of Geophysical and Ecological Instrumentation of the Siberian Branch of the Russian Academy of Sciences, Novosibirsk (photo 5).

It is a magnetic quadrupole mass spectrometer with double focusing, which is equipped with several interfaces for sample input, including a gas chromatograph equipped with an original concentrator-thermodesorber device. This device allows for express studies of gaseous and liquid samples.

The analysis duration does not exceed 2 — 3 minutes.

Photo 5. External appearance of the GCMS device (“NAVAL”)

The device's processing system is designed to control it, collect and process data. The format in which the research results are recorded allows data processing using programs such as «AMDIS», «MS NIST Search», as well as data processing programs from AGILENT TECNOLOGIES (USA).

This allows the device to be used to identify unknown substances using standard mass spectrometry databases. The device has already proven itself in the study of samples of explosives and toxic substances, environmental objects. The authors of this article tested it as a device for express drug analysis.

The results obtained exceeded all expectations and will soon be published in an academic journal.

For example, Fig. 1a shows a chromatogram of a methanol solution of heroin seized from illegal drug trafficking in Moscow.

Fig. 1a) chromatogram of a heroin sample seized
from illegal drug trafficking in March 2001 in Moscow;

Fig. 1b) mass spectrum corresponding to the chromatographic
peak with a retention time of 1.10 min;

Fig. 1c) heroin library mass spectrum;

Under the conditions used, a retention time of 0.91 min corresponds to 6-monoacetylmorphine, and 2.41 min to papaverine

From Fig. 1 it is evident that in 3 minutes it is possible to successfully separate the main components of heroin: diacetylmorphine and monoacetylmorphine, as well as papaverine. The resulting mass spectrum of diacetylmorphine is in good agreement with the library spectrum of this substance.

An important distinction of this equipment is the possibility of its use in mobile complexes, as it has special devices for transportation, and the ideology of adjustment to the needs of the end user, who has minimal training in mass spectrometry, was initially embedded in it.

Among the chemical tests, it is worth mentioning the “NARCOSPECTR” kit, produced by ZAO NIIIN MNPO “SPECTR” [2, 3].

In its tactical and technical characteristics, it significantly surpasses not only domestic but also foreign models.

Currently, this kit has been tested at the Main Directorate of the Forensic Science Center of the Ministry of Internal Affairs of Russia and approved by the Permanent Committee on Drug Control for conducting preliminary (indicative) analyses for the presence of narcotic drugs, psychotropic and potent substances (minutes of the meeting of the Permanent Committee on Drug Control No. 2/85-2002 of October 28, 2002).

Currently, Russian scientists are developing a detector of explosives (EV) and natural drugs (ND) based on the photonuclear method. The use of this method was first proposed by Nobel Prize winner Luis Alvarez in 1985.

Later it was experimentally verified by V. P. Trauer [4] and developed at the Lebedev Physical Institute of the Russian Academy of Sciences (FIAN) [5, 6]. The essence of the method consists in detecting in the examined volume an increased concentration of nitrogen and carbon of chemical elements that form the basis of all modern combat explosives and countermeasures. For this purpose, the registration of decay products of short-lived isotopes 12B (boron-12) and 12N (nitrogen-12) with half-lives of 20.2 and 11.0 ms, respectively, is used. These isotopes are produced as a result of photonuclear reactions on nitrogen (14N) and carbon (13C) when they are irradiated with gamma quanta with an energy greater than the threshold value E: for 14N – 24 and 31 MeV and for 13C 17 MeV. Isotopes 12B and 12N are active and in the process of decay emit electrons and positrons with a maximum energy of about 13 MeV and 17 MeV, which, moving in the substance, in turn induce gamma quanta.

The short exposure time required to detect explosives and NPs (20 ms) ensures high speed of the method.

The procedure for searching for explosives and NPs can be repeated at a frequency of 50 Hz, shifting the point of irradiation of the studied area and thus implementing the scanning examination mode.

Another advantage of the described method is that gamma quanta with high penetrating power are used as both the probing radiation and the carrier of the useful signal, which allows detecting explosives and PN in the concealing substance at a considerable depth.

Table 3. Main characteristics of the method

It should be noted that, with its high sensitivity, speed and selectivity, this method is capable of detecting explosives and PNs hidden by various substances of considerable thickness, which is associated with specific processes of interaction of secondary radiation with the substance. Thus, with a probability of more than 99%, 10 g of TNT and 50 g of heroin hidden under 30 mm of steel, 20 cm of water or 10 cm of concrete can be detected.

Thus, at present, domestic and foreign industry produces a fairly wide range of special equipment for conducting drug research in non-laboratory conditions.

It is designed to solve problems of conducting examinations of a large number of people, objects or premises in the shortest possible time in order to find those of them that must be thoroughly and carefully examined already in the laboratory.

In this regard, the methods and devices implemented on their basis for laboratory and non-laboratory practice differ significantly from each other. This also ensures the generally accepted division of the research process into the stages of preliminary and confirmatory analysis.

Literature

1. Guide for the Selection of Drug Detectors for Law Enforcement Applications //NIJ Guide 601–00, 2000.
2. Simonov E.A., Sorokin V.I., Kovalev A.V. Express Drug Detection Equipment //Special Equipment, 2002, No. 4, pp. 25–30.
3. Gaevsky A.V., Degtyarev E.V., Simonov E.A., Sorokin V.I. and others. Analytical examination of substances subject to special control in the Russian Federation //New drugs, 1999, No. 4, pp. 15 – 29.
4. W. P. Trower, The Nitrogen Camera and the Detection of Concealed Explosives , Nucl. Instr. & Meth. B79 (1993) 589.
5. A. S. Belousov, A. I. Karev, et al. Highly effective system for detecting hidden explosives //Science of production. 2000. 6. p. 33.
6. K. A. Belovintsev, A. I. Karev, and V. G. Kurakin, The Lebedev Physical Institute Race-Track Microtron, Nucl. Instr. & Meth. A261 (1987) 36.