Characterization and health risk assessment of PM2.5-bound organics inside and outside of Chinese smoking lounges.

PM2.5 samples were collected at six indoor public places that contained dedicated smoking lounges. Samples were taken in the smoking lounges, at two indoor locations outside of the lounges, and in outdoor air near the venues. Organic carbon (OC), elemental carbon (EC), and non-polar organic compounds including polycyclic aromatic hydrocarbons (PAHs), n-alkanes (n-C16 to n-C40), iso/anteiso-alkanes (C29 to C33), hopanes and phthalate esters (PAEs) were quantified. Average PM2.5 levels of 170.2 ± 85.9 µg/m3 in the lounges exceeded limits of 25 µg/m3 set by World Health Organization (WHO); these levels were 5.4 and 3.9 times higher than those indoors and outdoors, respectively. High ratios of OC to PM2.5, OC to EC, and PAHs diagnostic ratios in the lounges indicated contributions from environmental tobacco smoke (ETS). The maximum carbon number (Cmax) and carbon preference indices (CPI) for n-alkanes showed ETS transport from the enclosed lounges to nearby indoor non-smoking areas. Iso/anteiso-alkanes in the lounges were 876.5 ng/m3, ∼80 times higher than outdoor levels. 17α(H)-21ß(H),30-norhopane and 17α(H)-21ß(H),(22R)-homohopane were much higher in the lounges than outdoor air, but they cannot be directly attributed to ETS. Estimated carcinogenic risks of PAHs in the lounges exceeded the acceptable level of 10- 6.

[Application of synchronous fluorescence in identification of spilled oil at sea].

In order to screen and identify the source of spilled oils at sea, synchronous fluorescence scans combined with clustering analysis are proposed and applied to different crude oil and weathering crude oil. SFS data of deltal = 25 nm were recorded and dealt with clustering analysis. The cluster results of SFS data in the range of 300 - 500 nm show that the crude oil and the weathering oil could separate completely. And the crude oils from different sea areas, also collected at different time, clustered into different groups, respectively. The results indicate that this method could preliminarily selected, and maybe serves as an assistant method in oil spill identification.

Residues of organochlorine pesticides in near shore waters of LaiZhou Bay and JiaoZhou Bay, Shandong Peninsula, China.

The extent of organochlorine pesticides (OCPs) contamination in coastal waters around LaiZhou Bay and JiaoZhou Bay in Shandong Peninsula, northern China, was investigated. The areas around the two bays are both densely populated, thrive with intensive agriculture and industrial activities. Multi-techniques including GC-MS, GC-muECD coupled with chemical peak confirmation and strict QC procedures were used for the quantitative determination of 15 OCPs including alpha, beta, gamma and delta isomers of hexachlorocyclohexane (HCH), pentachloronitrobenzene (PCNB), heptachlor, aldrin, endosulfan, p,p'-DDE, dieldrin, endrin, p,p'-DDD, o,p'-DDT, p,p'-DDT and methoxychlor. The survey results show that contaminations by OCP residues remain widespread in the areas, but the averaged concentration levels are all below the regulatory limits, e.g., CMC limits (acute criterion values) specified in US Environmental Protection Agency (USEPA) and China national standards. Average concentration of OCPs in water samples were from undetectable to 3.8 ng l(-1) in LaiZhou Bay and from 0.1 to 3.9 ng l(-1) in JiaoZhou Bay, respectively. A comparison between the current and historical data shows a rapidly decreasing trend of OCPs over the past twenty years in the study areas.

Analysis of bacteria degradation products of methyl parathion by liquid chromatography/electrospray time-of-flight mass spectrometry and gas chromatography/mass spectrometry.

The biodegradation of the organophosphorus insecticide methyl parathion (MP) in aqueous environment by bacteria isolated from river sediment has been studied. Two species of bacteria which show strong MP degradation ability are identified as Shewanella and Vibrio parahaemolyticus. The biodegradation of MP proceeded rapidly with the formation of a series of intermediate products, which were analyzed using a combination of GC/MS and HPLC/ESI-TOFMS techniques. The major products tentatively identified include a series of reduced products of MP. Results demonstrate that the coupling of TOFMS to HPLC enhances further the capability of LC-MS in the identification of polar organic species in complex environmental samples. Degradation pathways leading to the formation of these products are proposed which involves first the reduction of nitro to amino group in MP, followed by combination with some intrinsic matters of bacteria. The mechanism and products from biodegradation are quite different from those of photocatalytic process for which the main intermediates included methyl paraoxon and 4-nitrophenol.

Identification of norharman as the cytotoxic compound produced by the sponge (Hymeniacidon perleve)-associated marine bacterium Pseudoalteromonas piscicida and its apoptotic effect on cancer cells.

Marine invertebrates harbour a wealth of micro-organisms in their bodies. Most of these micro-organisms can catabolize antibiotic compounds as chemical-defence compounds. These compounds not only play an important protective role for their producer and for their hosts, but also have high potential in medicinal applications. In order to discover natural anticancer products, 29 marine bacterial strains have been isolated from the sponge Hymeniacidon perleve, samples of which were collected from the intertidal zone during low tide off Nanji island in Eastern China. By means of a cytotoxicity bioassay, one strain, NJ6-3-1, with significant cytotoxic activity, was selected for culture in a 30-litre fermentation tank. The major cytotoxic compound in the metabolites of NJ6-3-1, separated by means of a bioassay-guided fractionation process, has been identified as norharman (a beta-carboline alkaloid) by electron-impact MS and NMR analyses. Norharman showed cytotoxicity towards both the HeLa cervical-cancer cell line and the BGC-823 stomach-cancer cell line, with an IC(50) of 5 microg/ml. Several methods were used to study the mechanism by which norharman is cytotoxic to HeLa cells. By means of an Acridine Orange/ethidium bromide dual-staining assay, condensation of chromatin was observed. A TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling) assay showed degradation of DNA. Flow-cytometric analysis indicated that norharman could arrest cells at the G(2)/M phase of the cell cycle. These results demonstrate the cytotoxic mechanism of norharman involves the induction of apoptosis in HeLa cells.

Investigation of zinc binding metallothioneins' polymerization in tris(hydroxymethyl)-aminomethane buffer by coupling of size exclusion chromatography with electrospray ionization mass spectrometry.

Polymerization of metallothioneins (MTs) is one of the commonly encountered puzzles in researching the structure and function of metallothioneins. In this work, a method involving SEC coupled with negative ion electrospray ionization mass spectrometry (ESI-MS) detection has been developed for the study of zinc binding MTs' polymerization in tris(hydroxymethyl)-aminomethane (TRIS) acetate buffer at physiological pH. This hyphenated technique allows separating the different polymeric states of MTs by SEC, followed by on-line identification of the individual MT subisoforms in each polymeric peak by ESI-MS detection. Purified MT subisoforms (MT-2d and MT-2a), MT-2d and MT-2a mixture and rabbit liver MT complexes were investigated in the experiments to confirm the results obtained. From the results, both oxidative polymerization and non-oxidative oligomerization were found. The cystein-dependent oxidation results in the tetrameric peak as shown in the chromatograms of oxidized MT-2d, and stable dimeric and monomeric of MT were detected in this peak by MS. For the dimeric and trimeric peaks, different MT subisoforms were detected. In the five major subisoforms detected in rabbit liver MT complexes, MT-2a and MT-2c exist primarily as trimer, while MT-2e, MT-2d and MT-1a exist mainly as dimer. Our results suggest that in the three kinds of polymers, dimer, trimer and tetramer that were found in samples, the tetramer comes from the oxidation of MT molecular; for the dimer and trimer resulting from cystein independent oligomerization, they are closely associated with the charge of subisoform.

Isolation and identification of flavonoids in licorice and a study of their inhibitory effects on tyrosinase.

Five different flavonoids were isolated from licorice after multistep chromatographic fractionation. The aim was to identify and characterize active components in licorice responsible for antibrowning activities and to seek new tyrosinase inhibitors for applications as antibrowning and depigmenting agents in the food and cosmetic industries. The isolated flavonoids were identified as liquiritin, licuraside, isoliquiritin, liquiritigenin (from Glycyrrhiza uralensis Fisch.), and licochalcone A (from Glycyrrhiza inflate Bat.) by UV, MS, (1)H NMR, and (13)C NMR analyses. The inhibitory potencies and capacities of these flavonoids toward monophenolase activity of mushroom tyrosinase were investigated. The IC(50) values of licuraside, isoliquiritin, and licochalcone A for monophenolase activity were 0.072, 0.038, and 0.0258 mM, respectively. A study of the mechanisms of monophenolase inhibition by these flavonoids indicated that they are all competitive inhibitors. Different from the above flavonoids, no inhibitory activity was observed for liquiritin, whereas liquiritigenin activated the monophenolase activity as a cofactor. The inhibitory effect of licuraside, isoliquiritin, and licochalcone A on diphenolase activity with l-DOPA as the substrate was much lower than those with l-tyrosine. Results suggest that licuraside, isoliquiritin, and licochalcone A have the high potential to be further developed into effective antibrowning and depigmenting agents.