Enhancement in sample collection for the detection of MDMA using a novel planar SPME (PSPME) device coupled to ion mobility spectrometry (IMS)

Abstract

Trace detection of illicit drugs challenges the scientific community to develop improved sensitivity and selectivity in sampling and detection techniques. Ion mobility spectrometry (IMS) is one of the prominent trace detectors for illicit drugs and explosives, mostly due to its portability, high sensitivity and fast analysis. Current sampling methods for IMS rely on wiping suspected surfaces or withdrawing air through filters to collect particulates. These methods depend greatly on the particulates being bound onto surfaces or having sufficient vapour pressure to be airborne. Many of these compounds are not readily available in the headspace due to their low vapour pressure. This research presents a novel SPME device for enhanced air sampling and shows the use of optimized IMS by genetic algorithms to target volatile markers and/or odour signatures of illicit substances. The sampling method was based on unique static samplers, planar substrates coated with sol-gel polydimethyl siloxane (PDMS) nanoparticles, also known as planar solid-phase microextraction (PSPME). Due to its surface chemistry, high surface area and capacity, PSPME provides significant increases in sensitivity over conventional fibre SPME. The results show a 50-400 times increase in the detection capacity for piperonal, the odour signature of 3,4-methylenedioxymethamphetamine (MDMA). The PSPME-IMS technique was able to detect 600 ng of piperonal in a 30 s extraction from a quart-sized can containing 5 MDMA tablets, while detection using fibre SPME-IMS was not attainable. In a blind study of six cases suspected to contain varying amounts of MDMA in the tablets, PSPME-IMS successfully detected five positive cases and also produced no false positives or false negatives. One positive case had minimal amounts of MDMA resulting in a false negative response for fibre SPME-IMS.

Improved Dynamic Headspace Sampling and Detection using Capillary Microextraction of Volatiles Coupled to Gas Chromatography Mass Spectrometry

“…So far, many preconcentration devices [22,23] have been developed to overcome the first challenge in headspace analysis and coupling the sampling devices to a gas chromatography -mass spectrometer (GC-MS) can help with the second challenge; however, restricted by the GC-MS injection port, the devices are limited in their shape, and therefore, surface area and phase volume. In the past few years, a novel preconcentration device was developed in the Almirall research group, planar solid phase microextraction (PSPME) [24,25], to achieve a larger surface area and phase volume [26], thus increasing the sampling throughput. A planar solid phase microextraction (PSPME) device has enlarged surface area and phase volume compared to the solid phase microextraction (SPME) fiber resulted from the well-designed, but flexible geometry configuration.…”

“…To overcome the two major drawbacks of SPME fibers, planar solid phase microextraction (PSPME) was invented by changing the geometry of SPME fibers into planar surfaces and coupled to existing ion mobility spectrometers for detection [79,24,25].…”

A review of developments and applications of thin‐film microextraction coupled to surface‐enhanced Raman scattering

“…According to the classical SPME equilibrium extraction theory, in the direct thin‐film microextraction, the relationship between the total extraction amount of the target analyte (n) and the initial concentration (C s ) of the target analyte in the sample matrix when the adsorption reaches equilibrium is as follows : …”

“…The current review intends to show the combination of thin‐film microextraction with surface‐enhanced Raman spectroscopy (TFME‐SERS). This method not only overcomes the disadvantage of the traditional TFME requiring specific device to be coupled to GC, LC, or ion mobility spectrometry , but the SERS detection can be performed directly on the surface of the enriched extraction material. Rapid detection methods with less time‐consuming, simple operation, and high sensitivity can be developed by this way.…”

Electrochemically controlled solid phase microextraction of ibuprofen based on nanostructure conducting molecular imprinted polypyrrole and selective analysis in biological and formulation samples using ion mobility spectrometry

“…[28][29][30][31] Recent applications include analysis of pharmaceutical actives and formulations, and structural and conformational studies in biological and biomedical research. [30][31][32][33][34][35][36] The current work is a continuation of our previous studies on developing electrochemically coated electrodes with PPy anion doped lms for selective extraction, clean-up, and quantication of trace amounts of IBP from human serum samples. The PPy lm, which was electropolymerized in the presence of the drug as a template molecule with subsequent overoxidation to create shape-complementary cavities was evaluated as CMIP.…”