Sewage and Organic Pollution Compounds in Nairobi River Urban Sediments Characterized by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS).

Nairobi River sediments from locations adjacent to the Kawangware and Kiambio slums were analyzed via Fourier transform ion cyclotron resonance mass spectrometry with atmospheric pressure photoionization (APPI-FT-ICR-MS). The data from these ultrahigh resolution, untargeted measurements provided new insights into the impacts of local anthropogenic activity, which included likely benzo- and dibenzothiophene pollution with a suspected petrogenic origin, and prominent surfactant-like compositions. Other features in the data included highly abundant tetra-oxygenated compounds, and oxygenated nitrogen compounds with sphingolipid interpretations.

Tracking the history of polycyclic aromatic compounds in London through a River Thames sediment core and ultrahigh resolution mass spectrometry.

Polycyclic aromatic compounds (PACs), including polycyclic aromatic hydrocarbons (PAHs) and heteroatom-containing analogues, constitute an important environmental contaminant class. For decades, limited numbers of priority PAHs have been routinely targeted in pollution investigations, however, there is growing awareness for the potential occurrence of thousands of PACs in the environment. In this study, untargeted Fourier transform ion cyclotron resonance mass spectrometry was used for the molecular characterisation of PACs in a sediment core from Chiswick Ait, in the River Thames, London, UK.

Investigating the Influence of -Heptane versus -Nonane upon the Extraction of Asphaltenes.

The composition of asphaltenes is of interest due to the challenges they pose for industry and their high complexity, encompassing a range of heteroatom contents, molecular weights, double bond equivalents (DBEs), and structural motifs. They are well-known for aggregating above critical concentrations, hindering the upstream and downstream processes. Asphaltenes are defined by solubility, as they are insoluble in light paraffins such as -heptane and soluble in aromatic solvents such as toluene.

Fingermark visualisation with iron oxide powder suspension: The variable effectiveness of iron (II/III) oxide powders, and Tween 20 as an alternative to Triton™ X-100.

The effectiveness of the current UK iron oxide powder suspension formulation, 'C-IOPS-09' (Triton X-100 based), for fingermark or latent fingerprint visualization is shown to be affected by variations between batches of the recommended iron oxide powder from Fisher Scientific (I/1100/53). When incorporated into the C-IOPS-09 formulation, a 2015 powder batch resulted in the detection of ∼19% fewer fingermarks, of broadly reduced contrast, when compared to powder suspension prepared with a 2008 batch of the same product. Furthermore, the 2015 powder batch was found to be unsuitable in experimental reduced-surfactant concentration powder suspension, because it caused surface-wide or background staining.

Sequential processing strategies for fingermark visualisation on uncirculated £10 (Bank of England) polymer banknotes.

An investigation was undertaken to assess the relative effectiveness of five fingermark visualisation process sequences on new, uncirculated £10 polymer banknotes from the Bank of England (BoE). Each sequence was challenged with the visualisation of 64 natural fingermarks on eight banknotes, of which half were aged for 2-3days and half were aged for 12-13days (32 donors contributed in each set). The sequences investigated were; After each process was applied, fingermark development was assessed under primary viewing conditions appropriate to the technique (white light or fluorescence).

Fingermark visualisation on uncirculated £5 (Bank of England) polymer notes: Initial process comparison studies.

Experiments were conducted to investigate the effectiveness of a range of fingermark visualisation processes on brand new, uncirculated, £5 polymer banknotes (and their test note predecessors), as produced by the Bank of England (BoE). In the main study of this paper, a total of 14 individual processes were investigated on BoE £5 polymer banknotes, which included both 'Category A' processes (as recommended in the Home Office Fingermark Visualisation Manual) as well as recently developed processes, including fpNatural 2 powder (cuprorivaite) from Foster+Freeman and a vacuum metal deposition sequence that evaporates silver followed by zinc. Results from this preliminary investigation indicate that fpNatural 2, multimetal deposition, Wet Powder Black, iron oxide powder suspension and black magnetic powder are the most effective processes on these uncirculated £5 BoE polymer banknotes, when viewed under "primary viewing" conditions (white light or fluorescence).