Validation and uncertainty estimation of UPLC-PDA method for the analysis of polycyclic aromatic hydrocarbons in concrete.

Human exposure to persistent organic contaminants, from building materials, negatively affects people's health and overall quality of life. This paper presents the validation and uncertainty assessment of the analytical method, developed for the simultaneous determination of 16 EPA polycyclic aromatic hydrocarbons (PAHs) in solid-solid concrete by ultra-performance liquid chromatography with photo diode-array detector. Linearity of calibration curves was good over the whole range of calibration. Limits of detection varied between 0.2 and 2.9µgkg-1. The accuracy in terms of recovery of the validated method is within the range from 54 to 106%. The developed method proved to be appropriate for analysis of PAHs and can be used for the quality control testing of concrete during the construction of new buildings, the old residences and related buildings associated with sick-building syndrome. In addition, this is the first reported method described for the evaluation of PAHs in solid-solid concrete.

Electrochemical oxidation of the polycyclic aromatic hydrocarbons in polluted concrete of the residential buildings.

Polycyclic aromatic hydrocarbons (PAH) have been listed by the United States Environmental Protection Agency (US EPA) and by the European Community as priority environmental pollutants. The removal of PAHs from soils, sediments and waste water has attracted attention of scientists and engineers for several decades. Electrochemical oxidation of PAH compounds in water, is receiving increasing attention, due to its convenience and simplicity. In this study we performed electrochemical oxidation of 16 EPA PAHs mixture in 10% NaCl aqueous solution in potentiostatic conditions, at voltage 1 V. Decrease of concentration of some individual PAHs, up to 70% referred to their starting concentration, after 60 min of electrolysis, was confirmed by UPLC/PDA analysis. In further work investigation was extrapolated to in situ removal of PAHs from concrete, as the medium where, to our knowledge, such way of PAH removal has not been investigated before. High concentrations of PAH contamination occurred in the concrete structure of the residential buildings in Belgrade in 2014. Application of DC voltage of 50 V between nickel and stainless steel electrodes packed in the concrete wall, moisturized with the 10% NaCl solution, led to considerable removal of the pollutants by oxidation process throughout the concrete.

Basic fibroblast growth factor stimulates functional recovery after neonatal lesions of motor cortex in rats.

Rats were given bilateral lesions of the motor cortex on the tenth day of life, and then received a daily subcutaneously injection of either basic fibroblast growth factor (FGF-2) or vehicle for 7 consecutive days. In adulthood, they were trained and assessed on a skilled forelimb reaching task. Although all lesion groups were impaired at skilled reaching, the postnatal day 10-lesioned group that received FGF-2 was less impaired than the lesion group that received the vehicle. Furthermore, the lesioned rats that received FGF-2 showed a filling of the lesion cavity with tissue, whereas the lesioned vehicle-treated rats still had a prominent lesion cavity. The functionality of the tissue filling the cavity, tissue surrounding it, and tissue from the motor cortex (in control rats) was assessed using intracortical microstimulation, and showed that stimulation of some sites from the filled cavity could evoke movement. The rats were perfused and processed for Golgi-Cox staining. Medium spiny neurons from the striatum were drawn and analyzed, and the results suggest that postnatal day 10 lesions of the motor cortex induced an increase in the length and complexity of these cells compared with those of non-lesioned rats. Our results suggest that FGF-2 may play an important role in recovery from early brain damage.