Direct Analysis of Aerosolized Chemical Warfare Simulants Captured on a Modified Glass-Based Substrate by “Paper-Spray” Ionization

Paper spray ionization mass spectrometry offers a rapid alternative platform requiring no sample preparation. Aerosolized chemical warfare agent (CWA) simulants trimethyl phosphate, dimethyl methylphosphonate, and diisopropyl methylphosphonate were captured by passing air through a glass fiber filter disk within a disposable paper spray cartridge. CWA simulants were aerosolized at varying concentrations using an in-house built aerosol chamber. A custom 3D-printed holder was designed and built to facilitate the aerosol capture onto the paper spray cartridges. The air flow through each of the collection devices was maintained equally to ensure the same volume of air sampled across methods. Each approach yielded linear calibration curves with R2 values between 0.98–0.99 for each compound and similar limits of detection in terms of disbursed aerosol concentration. While the glass fiber filter disk has a higher capture efficiency (≈40%), the paper spray method produces analogous results even with a lower capture efficiency (≈1%). Improvements were made to include glass fiber filters as the substrate within the paper spray cartridge consumable. Glass fiber filters were then treated with ammonium sulfate to decrease chemical interaction with the simulants. This allowed for improved direct aerosol capture efficiency (>40%). Ultimately, the limits of detection were reduced to levels comparable to current worker population limits of 1 × 10–6 mg/m3

Paper Spray Ionization: Applications and Perspectives

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

Genetic and Biochemical Studies of Phosphatase Activity of PhoR

In Escherichia coli, PhoR is the histidine kinase of the phosphate regulon. It has been postulated that PhoR may function as a phospho-PhoB phosphatase. Experiments with four precise phoR deletion mutants supported this hypothesis and suggested that this activity resides within the histidine phosphorylation domain. This biochemical activity was confirmed by using a separately expressed histidine phosphorylation domain

Proteomic, Metabolomic, and Lipidomic Analyses of Lung Tissue Exposed to Mustard Gas

Sulfur mustard (HD) poses a serious threat due to its relatively simple production process. Exposure to HD in the short-term causes an inflammatory response, while long-term exposure results in DNA and RNA damage. Respiratory tract tissue models were exposed to relatively low concentrations of HD and collected at 3 and 24 h post exposure. Histology, cytokine ELISAs, and mass spectrometric-based analyses were performed. Histology and ELISA data confirmed previously seen lung damage and inflammatory markers from HD exposure. The multi-omic mass spectrometry data showed variation in proteins and metabolites associated with increased inflammation, as well as DNA and RNA damage. HD exposure causes DNA and RNA damage that results in variation of proteins and metabolites that are associated with transcription, translation and cellular energy