Detection of tetrahydrocannabinol residues on hands by ion-mobility spectrometry (IMS). Correlation of IMS data with saliva analysis

Abstract

Ion-mobility spectroscopy (IMS) was evaluated as a high-throughput, cheap, and efficient analytical tool for detecting residues of tetrahydrocannabinol (THC) on hands. Regarding the usefulness of hand residues as potential samples for determining THC handling and abuse, we studied the correlation between data obtained from cannabis consumers who were classified as positive after saliva analysis and from those who were classified as positive on the basis of the information from hand-residue analysis. Sampling consisted of wiping the hands with borosilicate glass microfiber filters and introducing these directly into the IMS after thermal desorption. The possibility of false positive responses, resulting from the presence of other compounds with a similar drift time to THC, was evaluated and minimised by applying the truncated negative second-derivative algorithm. The possibility of false negative responses, mainly caused by competitive ionisation resulting from nicotine, was also studied. Graphical abstract THC residues: from hands to analytical signals.

Thermal desorption-ion mobility spectrometry: A rapid sensor for the detection of cannabinoids and discrimination of Cannabis sativa L. chemotypes

“…The K0 values of some of these peak signals agreed well with those previously reported in literature, i.e. the protonated monomer of CBD (1.08 ± 0.02 cm 2 V -1 s -1 ) [18] and Δ 9 -THC (1.05 ± 0.0004 and 1.06 cm 2 V -1 s -1 ) [15,18,19]. In these previous studies, only the K0 value of the most intense peak was pointed out in a drift time measurement using TD-IMS [15], while other used electrospray ionization, a soft volatilization/ionization source [18].…”

“…the protonated monomer of CBD (1.08 ± 0.02 cm 2 V -1 s -1 ) [18] and Δ 9 -THC (1.05 ± 0.0004 and 1.06 cm 2 V -1 s -1 ) [15,18,19]. In these previous studies, only the K0 value of the most intense peak was pointed out in a drift time measurement using TD-IMS [15], while other used electrospray ionization, a soft volatilization/ionization source [18]. Moreover, nicotinamide (with a high proton affinity, 918.3 kJ/mol) was employed as an internal calibrant using TD-IMS in the positive ionization mode [15,19].…”

“…Ion mobility spectrometry (IMS) is a potential alternative because of its rapid analysis time, simplicity, sensitivity, and portability [15]. IMS has been used as a sensor to analyze drugs.…”

“…Its use to detect ∆ 9 -THC in the positive ionization mode seems promising, while what happens in the negative ion mode is not known. However, some drawbacks were reported, such as poor selectivity and the existence of false-positive responses [15][16][17]. Moreover, most of these methods were tested using standards and no real samples [17][18][19][20].…”

Miniaturized Ion Mobility Spectrometer with a Dual-Compression Tristate Ion Shutter for On-Site Rapid Screening of Fentanyl Drug Mixtures

“…Ion mobility spectrometry (IMS) is a rapid analysis technique suitable for portable instruments and has been widely used in detecting illicit drugs. − In IMS, the introduced drug sample is ionized in the ionization region; then, a small packet of the product ions is injected into the drift region by an ion shutter for ion-mobility-based separation. In the ion shutter closed state, the applied gate closing voltage (GCV) usually produces a depletion region in which all ions will be discharged. , Therefore, ions cannot be effectively injected if they have not passed through the depletion region after the ion shutter opening interval, leading to the so-called ion mobility discrimination effect and hence poor sensitivity for slower drug ions .…”