Assessment of Polycyclic Aromatic Hydrocarbons in an Urban Soil Dataset

We compare a suite of Polycyclic Aromatic Hydrocarbons (Parent PAHs) in soils and air across an urban area (Belfast UK). Isomeric PAH ratios suggest that soil PAHs are mainly from a combustion source. Fugacity modelling across a range of soil temperatures predicts that four ring and larger PAHs from pyrene to indeno[1,2,3–cd]pyrene all partition strongly (>98%) to the soil compartment. This modelling also implies that these PAHs do not experience losses through partitioning to other phases (air, water) due to soil temperature effects. Such modelling may help in understanding the overall contaminantdistribution in soils. The air and soil data together with modelling suggests that care must be taken when considering isomeric ratios of compounds with mass lighter than 178 (i.e. phenanthrene and anthracene) in the soil phase. Comparison of duplicate and replicate samples suggest that field sampling of duplicates dominates uncertainty and validated methodologies for selection of field duplicates and lab splitting are required. As the urban soil four ring PAHs are at equilibrium in the soil phase, and have characteristic ratios that are dominated by a combustion source that is a single controlling factor over spatial distribution, methods that calculate background concentrations can be compared.

Photoelectrochemistry with quinone radical anions - Photoassisted reduction of halobenzenes and carbonyl compounds

Photoexcited electrochemically generated quinone radical anions reduced 1,2-dibromobenzene to bromobenzene, 1,4-dibromobenzene to bromobenzene and 4-chlorobenzonitrile to benzonitrile. In the presence of anthracene, 2-bromophenyl-, 4-bromophenyl- and 4-cyanophenyl-anthracenes were formed. With acetaldehyde, acetone, acetophenone, benzaldehyde and benzophenone, the major products were the corresponding pinacols, with small amounts of the two-electron secondary alcohols. In acetonitrile as solvent, cinnamonitriles, hydrocinnamonitriles and phenylglutaronitriles were formed in addition to the alcohols. Glyoxylic acid was reduced to tartaric, glycolic and malic acids. The reduction of CO₂ was unsuccessful.

Optimisation of singlet oxygen production from photosensitiser-incorporated, medically-relevant hydrogels

Photodynamic therapy and photodynamic antimicrobial chemotherapy are widely used, but despite this, the relationships between fluence, wavelength of irradiation and singlet oxygen (1O2) production are poorly understood. To establish the relationships between these factors in medically-relevant materials, the effect of fluence on 1O2 production from a tetrakis(4-N-methylpyridyl)porphyrin (TMPyP)-incorporated 2-hydroxyethyl methacrylate: methyl methacrylate: methacrylic acid (HEMA:MMA:MAA) copolymer, a total energy of 50.48 J/cm², was applied at varying illumination power, and times. 1O2 production was characterised using anthracene-9,10-dipropionic acid, disodium salt (ADPA) using a recently described method. Using two light sources, a white LED array and a white halogen source, the LED array was found to produce less 1O2 than the halogen source when the same power (over 500-600 nm) and time conditions were applied. Importantly, it showed that the longest wavelength Q band (590 nm) is primarily responsible for 1O2 generation, and that a linear relationship exists between increasing power and time and the production of singlet oxygen.

Optimization of singlet oxygen production from photosensitizer-incorporated, medically relevant hydrogels

Photodynamic therapy and photodynamic antimicrobial chemotherapy are widely used, but despite this, the relationships between fluence, wavelength of irradiation and singlet oxygen ((1) O2 ) production are poorly understood. To establish the relationships between these factors in medically relevant materials, the effect of fluence on (1) O2 production from a tetrakis(4-N-methylpyridyl)porphyrin (TMPyP)-incorporated 2-hydroxyethyl methacrylate: methyl methacrylate: methacrylic acid (HEMA: MMA:MAA) copolymer, a total energy of 50.48 J/cm(2) , was applied at varying illumination power, and times. (1) O2 production was characterized using anthracene-9,10-dipropionic acid, disodium salt (ADPA) using a recently described method. Using two light sources, a white LED array and a white halogen source, the LED array was found to produce less (1) O2 than the halogen source when the same power (over 500 - 600 nm) and time conditions were applied. Importantly, it showed that the longest wavelength Q band (590 nm) is primarily responsible for (1) O2 generation, and that a linear relationship exists between increasing power and time and the production of singlet oxygen.