Unambiguous Characterization of Analytical Markers in Complex, Seized Opiate Samples Using an Enhanced Ion Mobility Trace Detector-Mass Spectrometer

Abstract

Ion mobility spectroscopy (IMS)-based trace-compound detectors (TCDs) are powerful and widely implemented tools for the detection of illicit substances. They combine high sensitivity, reproducibility, rapid analysis time, and resistance to dirt with an acceptable false alarm rate. The analytical specificity of TCD-IMS instruments for a given analyte depends strongly on a detailed knowledge of the ion chemistry involved, as well as the ability to translate this knowledge into field-robust analytical methods. In this work, we introduce an enhanced hybrid TCD-IMS/mass spectrometer (TCD-IMS/MS) that combines the strengths of ion-mobility-based target compound detection with unambiguous identification by tandem MS. Building on earlier efforts along these lines (Kozole et al., Anal. Chem. 2011, 83, 8596-8603), the current instrument is capable of positive and negative-mode analyses with tightly controlled gating between the IMS and MS modules and direct measurement of ion mobility profiles. We demonstrate the unique capabilities of this instrument using four samples of opium seized by the Canada Border Services Agency (CBSA), consisting of a mixture of opioid alkaloids and other naturally occurring compounds typically found in these samples. Although many analytical methods have been developed for analyzing naturally occurring opiates, this is the first detailed ion mobility study on seized opium samples. This work demonstrates all available analytical modes for the new IMS-MS system including "single-gate", "dual-gate", MS/MS, and precursor ion scan methods. Using a combination of these modes, we unambiguously identify all signals in the IMS spectra, including previously uncharacterized minor peaks arising from compounds that are common in raw opium.

A High-Throughput Ion Mobility Spectrometry–Mass Spectrometry Screening Method for Opioid Profiling

“…When coupled with MS, IMS-MS provides multiple dimensions by which a molecule can be identified, as both the analyte’s m / z and CCS can be determined. DTIMS-MS has been used previously for the analysis of at least seven different opioids, including morphine, codeine, heroin, and 6-monoacetylmorphine. − Furthermore, the rapid nature of IMS-MS analyses is uniquely suited for further high-throughput applications, as demonstrated previous by Manicke et al using field asymmetric IMS (FAIMS)-MS for direct screening of urine samples for 3 opioids …”

Fourier Transform-Ion Mobility Linear Ion Trap Mass Spectrometer Using Frequency Encoding for Recognition of Related Compounds in a Single Acquisition

“…The quadrupole mass filter can be used either to analyze all ions in a transmission mode or in a mass-selective mode to detect ions of a single m / z . Triple quadrupoles offer the addition of tandem mass spectrometry capabilities. ,, Slow mass analyzers, such as quadrupole ion traps and Orbitraps, are unable to sample all of the mobility information from a single injection of ions. The mass scan in a quadrupole ion trap occurs over 30–85 ms, which is much slower than in time-of-flight instruments .…”