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Paper spray ionization has grown to become one of the most successful ambient ionization methods within the past decade. Requiring little to no sample preparation and being remarkably simple to construct, this technique has seen application in a wide number of fields. This review approaches the mechanism of how paper spray works, and seeks to better classify what it is and is not in a rapidly expanding field of ambient techniques. Additionally, many applications of the technique in clinical, forensic, environmental, and reaction monitoring regimes are explored. Finally, perspectives towards the future of how paper spray could be utilized will be expanded upon, including unexplored substrates and possibilities for the 'omics space.

Chemical warfare agents (CWAs) are devastating weapons of terror due to their highly lethal and dispersive nature. Powerful analytical tools are required to help create a knowledge base that will contribute to preventing attacks using these agents. Highly sensitive measurements must be made quickly with high selectivity for a wide range of potential molecular targets. Portable mass spectrometers have emerged as a robust platform for in-situ detection of chemical threats. However, due to size, weight, and power constraints, they are typically limited to a single mass analyzer with limited MS/MS capabilities, most notably the provision of full scan and product ion MS/MS spectra. Here we demonstrate the application of a new, highly efficient scanning methodology that uses a single linear quadrupole ion trap to acquire two-dimensional mass spectrometry data (2D MS/MS). With only a single scan, we show that it is possible to acquire mass-to-charge information on V-series chemical warfare agents– namely,: (1) Ethyl ({2-[bis(propan-2-yl)amino]ethyl}sulfanyl)(methyl)phosphinate (V1), (2) N,N-diethyl-2-(methyl-(2-methylpropoxy)phosphoryl)sulfanylethanamine (VR), (3) O-Butyl S-[2-(diethylamino)ethyl] methylphosphonothioate (VX) and (4) S-[2-(Diethylamino)ethyl] O-ethyl methylphosphonothioate (VM) - as precursors while simultaneously (in the same scan) acquiring product ion spectra for each CWA via mass spectral microfeatures. For mixtures of V-series agents, 2D MS/MS is a time- and sample-efficient method for obtaining MS/MS data. Discussed here are advantages and limitations of 2D MS/MS compared to conventional data-dependent product ion MS/MS scans.

The effect of ambient environmental conditions on a gas chromatography-atomic emission detection (GC-AED) system was characterized. The environmental stimuli was shock and vibration due to operating the hardware in a mobile analytical laboratory. The effect of large temperature change was also examined. System performance using a reference sample and operational recommendations are given.