Improving the Fluorescence Detectability of Polycyclic Aromatic Hydrocarbons for Evaluation of Workplace Environments of Cement Industries Processing Organic Residues

The burning of organic residues and wastes in furnaces of cement industries has been an attractive and lucrative approach to eliminate stocks of these pollutants. There is a potential risk for producing PAH in the workplace of industries burning organic wastes, so that highly sensitive analytical methods are needed for monitoring the air quality of these environments. An official method for determination of PAH is based on liquid chromatography with fluorescence detection at fixed excitation and emission wavelengths. We demonstrate that a suitable choice of these wavelengths, which are changed during the chromatographic run, significantly improves the detectability of PAH in atmosphere and particulate matter collected in cement industries.

Fungal community associated with marine macroalgae from Antarctica

Filamentous fungi and yeasts associated with the marine algae Adenocystis utricularis, Desmarestia anceps, and Palmaria decipiens from Antarctica were studied. A total of 75 fungal isolates, represented by 27 filamentous fungi and 48 yeasts, were isolated from the three algal species and identified by morphological, physiological, and sequence analyses of the internal transcribed spacer region and D1/D2 variable domains of the large-subunit rRNA gene. The filamentous fungi and yeasts obtained were identified as belonging to the genera Geomyces, Antarctomyces, Oidiodendron, Penicillium, Phaeosphaeria, Aureobasidium, Cryptococcus, Leucosporidium, Metschnikowia, and Rhodotorula. The prevalent species were the filamentous fungus Geomyces pannorum and the yeast Metschnikowia australis. Two fungal species isolated in our study, Antarctomyces psychrotrophicus and M. australis, are endemic to Antarctica. This work is the first study of fungi associated with Antarctic marine macroalgae, and contributes to the taxonomy and ecology of the marine fungi living in polar environments. These fungal species may have an important role in the ecosystem and in organic matter recycling.

Catalytic hydrodechlorination of chlorobenzene over supported palladium catalyst in buffered medium

The catalytic hydrodechlorination (HDC) reaction, which is an attractive abatement process for chlorinated organic wastes, was studied over a magnetically recoverable supported Pd(0) catalyst. We investigated the most favorable reaction conditions under which to obtain the highest substrate conversion rates while preserving the catalyst properties and morphology. Sodium hydroxide, triethylamine and buffered solutions were used as proton scavengers in the HDC of chlorobenzene under mild conditions. It was observed that sodium hydroxide caused corrosion of the silica support, triethylamine in 2-propanol preserved the morphology of the catalyst which could be recycled for up to five successive H DC reactions, and aqueous buffer solutions preserved the catalyst morphology and the catalytic activity for up to four successive HDC reactions. The use of buffer solutions to neutralize the HCl formed during the HDC reaction is an interesting, less aggressive, alternative approach to HDC reactions. (C) 2010 Elsevier B.V. All rights reserved.

Determination of volatile organic compounds in recycled polyethylene terephthalate and high-density polyethylene by headspace solid phase microextraction gas chromatography mass spectrometry to evaluate the efficiency of recycling processes

A method for the determination of volatile organic compounds (VOCs) in recycled polyethylene terephthalate and high-density polyethylene using headspace sampling by solid-phase microextraction and gas chromatography coupled to mass spectrometry detection is presented. This method was used to evaluate the efficiency of cleaning processes for VOC removal from recycled PET. In addition, the method was also employed to evaluate the level of VOC contamination in multilayer packaging material containing recycled HDPE material. The optimisation of the extraction procedure for volatile compounds was performed and the best extraction conditions were found using a 75 mu m carboxen-polydimethylsiloxane (CAR-PDMS) fibre for 20 min at 60 degrees C. The validation parameters for the established method were linear range, linearity, sensitivity, precision (repeatability), accuracy (recovery) and detection and quantification limits. The results indicated that the method could easily be used in quality control for the production of recycled PET and HDPE. (C) 2011 Elsevier B.V. All rights reserved.

Determination of polyamines in organic extracts from roots of Canavalia ensiformis by capillary electrophoresis

A rapid, selective and specific capillary zone electrophoresis method to determine polyamines in organic extracts from roots of Canavalia ensiformis (Jack Beans) was developed using ultra violet (UV) detection. Canavalia ensiformis is relatively free from diseases and it is used as reference in allelopathy studies. Polyamines are widely distributed in plant and it could be involved in plant pathogen interactions. Optimal separation was achieved using 15 mmol.L-1formic acid (pH 3.0) + 4 mmol.L-1 imidazole as a background electrolyte. It was possible to identify and quantify the polyamines on herbal samples in the presence of other phytochemical substances and analyze them quickly (up to 6 min). The applicability of this method was evaluated in crude organic extracts from roots of Canavalia ensiformis.