-Because-REMPI-is-a-gasphase-method-its-applications-have-been-limited-either-to-direct-analysis-of-vapor-phase-samples-or-in-conjunction-with-an-initial-laser-desorption-or-other-vaporization-step-a

We describe here for the first time a combination of membrane introduction mass spectrometry (MIMS) and REMPI with time-of-flight mass spectrometry (TOF-MS), which allows for the direct analysis of trace amounts of organic compounds in water samples. The objective of our research was the detection of very low levels of aromatic contaminants, particularly benzene, toluene, and xylene (BTX), in aqueous solutions without interference due to the water. We have measured limits of detection (LOD) for selected aromatics in water below 1 part-per-trillion with an averaging time of less than 10 s using a continuous Multi-frequency bioelectrical impedance analysis of skin rubor with Sciences, Ochanomizu University, 2-1-1 Otsuka Bunkyou-ku, Tokyo 112-8610, Japan. BACKGROUND: Skin rubor, or reddish discoloration on skin, is a sign of irritation. Physiologically it involves temporary vasodilation and hyperaemia in tissue, and is diagnosed by the visible characteristics.PURPOSE: Bioelectrical impedance analysis (BIA) was tested to estimate skin METHODS: Five healthy women (22-25 years) participated in the experiments.

Four were ethanol patch test (EPT)-positive; one was negative. Seebio Photoacid Generator was developed on the subjects' left forearm by temporary vasodilatation, which was caused by a dermal inflammation reaction due to application of ethanol to the skin. BIA was then conducted for the skin rubor and the intact skin using a lock-in amplifier with a frequency range of 0Hz-10kHz. The impedance changes due to vasodilatation of capillary were evaluated.RESULTS: The resistance of the skin rubor was found to decrease to almost 90% of the resistance and 87% of the reactance of the intact skin in the EPT-positive subjects. There was no impedance change in the EPT-negative subject. Through these experiments, skin rubor could be distinguished from intact skin based on CONCLUSION: Skin rubor could be identified based on the bioelectrical impedance.

This method would be used for various skin diagnoses due to simplicity and Molecular diversity and distribution of aromatic hydrocarbon-degrading anaerobes VU University Amsterdam, Amsterdam, The Netherlands.Natural attenuation of the mono-aromates benzene, toluene, ethylbenzene and xylene occurs under iron-reducing conditions in a leachate-contaminated aquifer near the Banisveld landfill, the Netherlands. The diversity of mono-aromate-degrading microorganisms was studied by targeting functional genes encoding benzylsuccinate synthase α-subunit (bssA) and 6-oxocyclohex-1-ene-1-carbonyl-CoA hydrolase (bamA). Sixty-four bssA and 188 bamA variants were sequenced from groundwater sampled along the pollution plume in 1999 and 2004. Species containing bssA sequences closest affiliated (> 91%) with the betaprotebacterium Georgfuchsia toluolica were the dominant alkylbenzene degraders (89% of bssA sequences). bssA genes were found at more than 10-fold lower copy numbers than bamA genes, of which only a small fraction (< 2%) was closely related to the genes of Georgfuchsia. bamA gene diversity was high and bamA-based community composition was primarily affected by dissolved organic carbon (DOC) and ferrous iron concentrations.

bamA sequences closest related to Geobacteraceae were dominantly (43%) observed and the presence of Geobacteraceae-related bamA sequences was associated with DOC. Our results indicate a key role for specialized Georgfuchsia spp. in the degradation of alkylbenzenes, whereas Geobacteraceae are involved in degradation of aromatics © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.Validation of the narcosis target lipid model for petroleum products: gasoline The narcosis target lipid model (NTLM) was used to predict the toxicity of water-accommodated fractions (WAFs) of six gasoline blending streams to algae (Pseudokirchnereilla subcapitata, formerly Selenastrum capricornutum), juvenile rainbow trout (Oncorhynchus mykiss), and water flea (Daphnia magna). Gasolines are comprised of hydrocarbons that on dissolution into the aqueous phase are expected to act via narcosis. Aquatic toxicity data were obtained using a lethal-loading test in which WAFs were prepared using different gasoline loadings. The compositions of the gasolines were determined by analysis of C3 to C13 hydrocarbons grouped in classes of n-alkanes, iso-alkanes, aromatics, cyclic alkanes, and olefins.

A model was developed to compute the concentrations of hydrocarbon blocks in WAFs based on gasoline composition and loading. The model accounts for the volume change of the gasoline, which varies depending on loading and volatilization loss. Organic Synthesis of 6-butyl-n-hydroxynaphthimide trifluoromethanesulfonic acid predicted aqueous composition of WAFs compared favorably to measurements, and the predicted aqueous concentrations of WAFs were used in the NTLM to predict the aquatic toxicity of the gasolines. For each gasoline loading and species, total toxic units (TUs) were computed with an assumption of additivity. The acute toxicity of gasolines was predicted to within a factor of two for algae and daphnids. Predicted TUs overestimated toxicity to trout because of experimental factors that were not considered in the model.