Overview
The use of portable spectrometers in the field has expanded significantly over the past forty years. Modern systems based on ion mobility spectrometry were deployed in the early 1980s for the detection and identification of chemical agents by the military. These systems have since been adapted to detect explosives and other toxic chemicals and are still commonly used by the military and within the aviation security industry.
Portable systems based upon other technologies including infrared (IR), Raman, gas chromatography-mass spectrometry (GC-MS), and high-pressure mass spectrometry (HPMS) have also become commercially available and are being used to reliably detect and identify chemicals at the sample site. These systems have proved themselves to be valuable for the analysis of illicit drugs and related substances.
There are distinct advantages to taking spectrometers into the field, to the sample, and immediately obtaining actionable information. Regarding the analysis of illicit drugs, these benefits include supporting investigations and prosecutions of drug-related offenses, evaluation of the hazardous nature of chemicals at the sites of clandestine laboratories, testing drug substances, and determining whether lethal substances like fentanyl, even when encountered at low doses, are present.
Portable Spectrometers
Advancements in technology, including improvements in computing power, battery power/power management, and consumer electronics, among others, have enabled the development and commercial availability of portable spectrometers for use in a wide breadth of applications [1].
These systems are now routinely deployed for many different uses, including the provision of personal protection of soldiers on the battlefield [2], and at recycling facilities to sort scrap materials [1,3,4]. The availability and use of these systems are so extensive that a 2018 review article on the topic of portable spectrometers [5] was followed up by a two-volume text published in 2021, containing over 1,100 pages detailing the technologies, instrumentation, and applications of portable spectroscopy and spectrometry [6,7].
The first modern portable spectrometer that was widely deployed for use was an ion mobility spectrometer (IMS) released in 1981 for the detection and identification of chemical agents in the military theater. Portable IMS systems were later adapted and used for the detection of explosives within the aviation industry and are still used extensively to detect these threats [2]. The first portable gas chromatograph-mass spectrometer (GC-MS) intended for use in the field was released in 1996 initially for the identification of hazardous air pollutants [8].
Portable GC-MS has since been applied in many other industries including by the armed services for the detection and identification of dangerous chemicals in military theater [9–14]. The first attenuated total reflection (ATR)-based mid-infrared (IR) portable system was introduced in 2000 and widely deployed to support the missions of the emergency-response community for the analysis of white powders and other dangerous threats that were commonly encountered after 9/11 [15].
Their use has extended to many other industries and these systems are commonly deployed for a variety of different applications [16–22]. Portable Raman systems were introduced to the market in 2005 [1] and, especially because of their ability to perform analysis in a point-and-shoot mode rather than requiring contact with the sample, have become a go-to first choice for the detection and identification of hazardous threats in the field despite some sampling limitations.
As is clear, portable systems are typically introduced for one application, and then are adapted for use in others. It is no wonder that all these portable detectors (and others) are now applied in the field for the analysis of illicit drugs and related substances. Figure 1 summarizes the history of initial technology deployments for portable spectrometers used in the field.
Read the full article on page 17 in Wiley Analytical Science Magazine Volume 8 – Dec/22.
