Related Articles

• Rapid detection of fentanyl, fentanyl analogues, and opioids for on-site or laboratory based drug seizure screening using thermal desorption DART-MS and ion mobility spectrometry

  Fentanyl and fentanyl analogues represent a current and emerging threat in the United States as pure illicit narcotics and in mixtures with heroin. Because of their extreme potency, methods to safely and rapidly detect these compounds are of high interest. This work investigates the use of thermal desorption direct analysis in real time mass spectrometry (TD-DART-MS) and ion mobility spectrometry (IMS) as tools for the rapid and sensitive (nanogram to picograms) detection of fentanyl, 16 fentanyl analogues, and five additional opioids. Competitive ionization studies highlight that detection of these compounds in the presence of heroin is readily achievable, down to 0.1% fentanyl by mass with TD-DART-MS. With IMS, detection of nanogram levels of fentanyl in a binary fentanyl and heroin mixture is possible but can be complicated by decreased resolution in certain commercial instrument models. Modifications to the alarm windows can be used to ensure detection of fentanyl in binary mixtures. Additionally, three complex background matrices (fingerprint residue, dirt, and plasticizers) are shown to have a minimal effect of the detection of these compounds. Wipe sampling of the exterior of bags of questioned powders is shown to be a safe alternative method for field screening and identification, removing the need to handle potentially lethal amounts of material.
• Instantaneous Detection of Explosives on Clothing

  The detection of explosives is of vital importance in forensic applications and in preventing criminal or terrorist activity. The analytical detection of explosives on surfaces is normally done by using solvent extractions or wipes and chromatography or chromatography combined with mass spectrometry. This is inefficient because solvent extractions and wipes only result in a partial transfer of material from the surface into the sampling material. Furthermore, the chromatographic analysis can be time-consuming and requires the use of disposable solvents (an environmental concern). The JEOL AccuTOF™ with Direct Analysis in Real Time (DART™) has demonstrated the capability to detect both volatile and involatile explosives on surfaces such as plastic, cloth, concrete, glass, cardboard, metal, and more. No wipes or solvent extractions are required. The method is instantaneous, environmentally friendly, and does not require solvents. An example is shown in this application note.
• Selective detection of active pharmaceutical ingredients in tablet formulations using solid-state NMR spectroscopy

  Atomic-level characterization of active pharmaceutical ingredients (API) is crucial in pharmaceutical industry because APIs play an important role in physicochemical properties of drug formulations. However, the analysis of targeted APIs in intact tablet formulations is less straightforward due to the coexistence of excipients as major components and different APIs at dilute concentrations (often below 10 ​wt% loading). Although solid-state (ss) NMR spectroscopy is widely used to investigate short-range order, polymorphism, and pseudo-polymorphism in neat pharmaceutical compounds, the analysis of complex drug formulations is often limited by overlapped signals that originate from structurally different APIs and excipients. In particular, such examples are frequently encountered in the analysis of 1H ssNMR spectra of pharmaceutical formulations. While the high-resolution in 1H ssNMR spectra can be attained by, for example, high magnetic fields accompanied by fast magic-angle spinning (MAS) approaches, the spectral complexity associated with the mixtures of compounds hinders the accurate determination of chemical shifts and through-space proximities. Here we propose a fast MAS (70 ​kHz) NMR experiment for the selective detection of 1H signals associated with an API from a severely overlapped NMR spectrum of a tablet formulation. Spectral simplification is achieved by combining (i) symmetry-based dipolar recoupling (SR412) rotational-echo saturation-pulse double-resonance (RESPDOR) with phase-modulate (PM) saturation pulses, (ii) radio frequency-driven recoupling (RFDR), and (iii) double-quantum excitation using Back-to-Back (BaBa) pulse sequence elements. First, 1H sites in close proximities to 14N nuclei of an API are excited using a PM-S-RESPDOR sequence, and simultaneously, the other unwanted 1H signals of excipients are suppressed. Then, 1H magnetization transfer to adjacent 1H sites in the API is achieved by spin diffusion process using a RFDR sequence, which polarizes to 1H sites within the crystalline API regions of the drug formulation. Next, a PM-S-RESPDOR-RFDR sequence is combined with a Back-to-Back (BaBa) sequence to elucidate local-structures and 1H–1H proximities of the API in a dosage form. The PM-S-RESPDOR-RFDR-BaBa experiment is employed in one- (1D) and two-dimensional (2D) versions to selectively detect the 1H ssNMR spectrum of l-cysteine (10.6 ​wt% or 0.11 ​mg) in a commercial formulation, and compared with the spectra of neat l-cysteine recorded using a standard BaBa experiment. The 2D 1H double-quantum−single-quantum (DQ-SQ) spectrum of the API (l-cysteine)-detected pharmaceutical tablet is in good agreement with the 2D 1H DQ-SQ spectrum obtained from the pure API molecule. Furthermore, the sensitivity and robustness of the experiment is examined by selectively detecting 1H{14N} signals in an amino acid salt, l-histidine.H2O.HCl.
• Selective detection of active pharmaceutical ingredients in tablet formulations using solid-state NMR spectroscopy

  Highlights: • Selective detection of 1H signals of API in a tablet formulation is proposed. • 1H signals of excipients are suppressed. • 1H signals in the vicinity of nuclei (here 14N) which only appear in API are excited. • 1H{14N} magnetization is diffused to 1Hs in API crystals by RFDR recoupling.
• Detection of Explosives in Muddy Water

  The AccuTOF time-of-flight mass spectrometer equipped with Direct Analysis in Real Time (DART™) has been used to detect a wide variety of explosives in or on a variety of materials ranging from solutions to samples deposited on surfaces ranging from ABS plastic to metal, clothing and cardboard. Detection is rapid, specific, and sensitive.
• Instantaneous Detection of the “Date-Rape” Drug -- GHB

  Gamma hydroxybutyrate (GHB) is a fast-acting central nervous system depressant. Prior to its ban by the FDA in 1990, GHB was sold in bodybuilding formulas. It has been abused as a euphoriant. Because it is colorless and odorless, it can be added to alcoholic drinks of unsuspecting victims. An overdose can result in serious consequences, including respiratory depression and coma. GHB was classified as a Schedule I Controlled Substance in March, 2000. Detection of GHB is problematic. GC/MS and LC/ MS methods are time consuming. A rapid colorimetric assay for GHB has been developed, but this assay suffers from some limitations. For example, ethanol produces the same colorimetric response as GHB. The AccuTOF™ mass spectrometer equipped with Direct Analysis in Real Time (DART™) can rapidly detect GHB anion (C4H7O3 -, m/z 103.0395) on surfaces, in urine, and in ethanol. No solvent extraction, wipes, or chromatography are required. Examples are shown in the figures below.