Comparison of sulfur isotope ratio measurements by various techniques, and the δ(34)S values of some sulur standards

Three techniques (combustion of Ag(2)S by Cu(2)O, thermal decomposition of BaSO(4) and KIBA reagent method under vacuum) for sulfur isotope ratio measurements of geological samples are described in detail. The δ(34)S values of three working standards (MSS-2, MSS-3 and MSS-4) obtained by these techniques for the last 13 years were compared (Table 1 and Fig. 3): the most acceptable values of the three standards are +21.5, +3.5 and +4.5‰, respectively

Concentrations of Chemical Components, Including ^<210>Pb, Present in Aerosols Collected at Naha, Okinawa Prefecture, a Sub-tropical Region of Japan

Aerosol samples were collected at Naha, Okinawa Prefecture, Japan during July 2001 to March 2005 to elucidate the concentrations of chemical components, including ^Pb, present in air for a sub-tropical region of Japan. The NO^-_3, SO^_4, NH^+_4 and Ca^+_2 concentrations had clear seasonal variations and were high in winter to spring and low in summer. ^Pb concentrations ranged from 0.10 to 1.52 mBq m^ and were low in summer and high in the other three seasons. The source of sulfur compounds in the aerosol samples was clarified by combining the sulfur isotope ratio δ^S and ^Pb concentrations. The multi-isotope method using δ^S and ^Pb concentrations was judged to be a good tool for understanding the transported sulfur source

Simultaneous Screening of Major Flame Retardants and Plasticizers in Polymer Materials Using Pyrolyzer/Thermal Desorption Gas Chromatography Mass Spectrometry (Py/TD–GC–MS)

This study was conducted with the aim of achieving the simultaneous screening of various additives in polymer materials by utilizing a solvent-free pyrolyzer/thermal desorption gas chromatography mass spectrometry (Py/TD-GC–MS) method. As a first step to achieve this goal, simultaneous screening has been examined by selecting major substances representing plasticizers and flame retardants, such as short chain chlorinated paraffins (SCCPs), decabromodiphenyl ether (DecaBDE), hexabromocyclododecane (HBCDD), and di(2-ethylhexyl) phthalate (DEHP). A quantitative MS analysis was performed to check for the peak areas and sensitivities. Since Py/TD-GC–MS is fraught with the risk of thermal degradation of the sample, temperatures during the analytical process were finely tuned for securing reliable results. The instrumental sensitivity was confirmed by the S/N ratio on each component. The detection limits of all components were less than 50 mg/kg, which are sufficiently lower than the regulatory criteria. With regard to reproducibility, a relative standard deviation (RSD) of about 5% was confirmed by employing a spike recovery test on a polystyrene polymer solution containing mixed standard solution (ca. 1000 mg/kg). In conclusion, the results obtained in this study indicate that Py/TD-GC–MS is applicable for the screening of major flame retardants and plasticizers in real samples with sufficient reproducibility at regulatory levels

Dietary Exposure to Flame Retardant Tris (2-Butoxyethyl) Phosphate Altered Neurobehavior and Neuroinflammatory Responses in a Mouse Model of Allergic Asthma

Tris (2-butoxyethyl) phosphate (TBEP) is an organophosphate flame retardant and used as a plasticizer in various household products such as plastics, floor polish, varnish, textiles, furniture, and electronic equipment. However, little is known about the effects of TBEP on the brain and behavior. We aimed to examine the effects of dietary exposure of TBEP on memory functions, their-related genes, and inflammatory molecular markers in the brain of allergic asthmatic mouse models. C3H/HeJSlc male mice were given diet containing TBEP (0.02 (TBEP-L), 0.2 (TBEP-M), or 2 (TBEP-H) &mu;g/kg/day) and ovalbumin (OVA) intratracheally every other week from 5 to 11 weeks old. A novel object recognition test was conducted in each mouse at 11 weeks old. The hippocampi were collected to detect neurological, glia, and immunological molecular markers using the real-time RT-PCR method and immunohistochemical analyses. Mast cells and microglia were examined by toluidine blue staining and ionized calcium-binding adapter molecule (Iba)-1 immunoreactivity, respectively. Impaired discrimination ability was observed in TBEP-H-exposed mice with or without allergen. The mRNA expression levels of N-methyl-D aspartate receptor subunits Nr1 and Nr2b, inflammatory molecular markers tumor necrosis factor-&alpha; oxidative stress marker heme oxygenase 1, microglia marker Iba1, and astrocyte marker glial fibrillary acidic protein were significantly increased in TBEP-H-exposed mice with or without allergen. Microglia and mast cells activation were remarkable in TBEP-H-exposed allergic asthmatic mice. Our results indicate that chronic exposure to TBEP with or without allergen impaired object recognition ability accompanied with alteration of molecular expression of neuronal and glial markers and inflammatory markers in the hippocampus of mice. Neuron-glia-mast cells interaction may play a role in TBEP-induced neurobehavioral toxicity

Concentrations of Chemical Components, Including 210Pb, Present in Aerosols Collected at Naha, Okinawa Prefecture, a Sub-tropical Region of Japan

Aerosol samples were collected at Naha, Okinawa Prefecture, Japan during July 2001 to March 2005 to elucidate the concentrations of chemical components, including 210Pb, present in air for a sub-tropical region of Japan. The NO3-, SO42-, NH4+ and Ca2+ concentrations had clear seasonal variations and were high in winter to spring and low in summer. 210Pb concentrations ranged from 0.10 to 1.52 mBq m-3 and were low in summer and high in the other three seasons. The source of sulfur compounds in the aerosol samples was clarified by combining the sulfur isotope ratio δ34S and 210Pb concentrations. The multi-isotope method using δ34S and 210Pb concentrations was judged to be a good tool for understanding the transported sulfur source