多溴联苯醚降解的代谢途径

添加型阻燃剂多溴联苯醚(PBDEs)由于具有优异的阻燃性能,已被广泛应用于各种消费品中。PBDEs具有低水溶性,会强烈吸附有机物,导致PBDEs在环境介质和食物链中大量富积,对人类和动物都造成巨大危害。对多溴联苯醚生物降解、光降解和零价铁降解过程中的代谢途径和代谢过程中所需的酶进行综述,为多溴联苯醚的修复提供理论基础。     

Particle-phase dry deposition and air-soil gas exchange of polycyclic aromatic hydrocarbons (PAHs) in Izmir, Turkey

Ambient air and dry deposition samples were collected at suburban and urban sites in Izmir, Turkey. Atmospheric total (particle+gas) ∑(14)PAHs concentrations were 36±39 and 144±163 ng m(-3) for suburban and urban sites, respectively. Phenanthrene was the most abundant compound at all sites, and all samples were dominated by low molecular weight PAHs. Average particulate ∑(14)PAH dry deposition fluxes were 8160±5024 and 4286±2782 ng m(-2) day(-1) and overall average particulate dry deposition velocities were 1.5±2.4 and 1.0±2.3 cm s(-1) for suburban and urban sites, respectively. Soil samples were collected at suburban site. Average soil concentration for ∑(14)PAH was 55.9±14.4 ng g(-1) dry weight. Calculated gas-phase air-soil exchange fluxes indicated that fluorene, phenanthrene, anthracene, and carbazole were deposited to soil in winter while they were volatilized in summer. Other compounds (fluoranthene-benzo[g,h,i]perylene) were deposited to soil in both periods. Annual average fluxes of PAHs representing soil to air (i.e., gas volatilization) and air to soil transfer (i.e., gas absorption, dry deposition, and wet deposition) processes were also compared. All processes were comparable for Σ(14)PAHs however their input was dominated by gas absorption. Gas absorption dominated for lower molecular weight PAHs, however dry deposition dominated for higher molecular weight PAHs. The results have suggested that for fluorene, soil and air may be approaching a steady state condition. For the remaining compounds, there was a net accumulation into the soil.     

A study of indoor radon levels in rural dwellings of Ezine (Canakkale, Turkey) using solid-state nuclear track detectors

Indoor radon activity level and radon effective dose (ED) rate have been carried out in the rural dwellings of Ezine (Canakkale) during the summer season using Radosys-2000, a complete set suitable to radon concentration measurements with CR-39 plastic alpha track detectors. The range of radon concentration varied between 9 and 300 Bq m(-3), with an average of 67.9 (39.9 SD) Bq m(-3). Assuming an indoor occupancy factor of 0.8 and 0.4 for the equilibrium factor of radon indoors, it has been found that the 222Rn ED rate in the dwellings studied ranges from 0.4 to 5.2 mSv y(-1), with an average value of 1.7 (1.0) mSv y(-1). There is a possibility that low radon concentrations exist indoors during the summer season in the study area because of relatively high ventilation rates in the dwellings. A winter survey will be needed for future estimation of the annual ED.     

Determination of priority polybrominated diphenyl ethers by isotope dilution gas chromatography(electron ionization)MS using 81Br-labeled standards

A mixture of (81)Br-labeled polybrominated diphenyl ethers (PBDEs), previously synthesized in our laboratory, was separated by liquid chromatography for the individual isolation of different (81)Br-labeled PBDEs containing from 3 to 6 bromine atoms. The different fractions were collected, and a mixed labeled standard was then prepared adequate for the determination of priority PBDEs (congeners 28, 47, 99, 100, 153, and 154) in environmental samples. The spike mixture was then characterized using gas chromatography(electron ionization)MS (GC(EI)MS) both in isotope composition and concentration in combination with multiple least-squares. Contamination from natural abundance BDEs 153 and 154 was detected in the spike mixture, and a new isotope dilution equation was developed to take into account the natural abundance contribution from the spike. The spike mixture was shown to be stable during at least 4 months, and no isotope exchange between natural abundance and labeled PBDEs was detected during this period of time. Finally, the (81)Br-labeled PBDEs standard was used for the determination of congeners 28 (+33), 47, 49, 99, 100, 153, and 154 in a standard reference material (Lake Michigan fish tissue SRM 1947) using three different sample to spike ratios. No methodological calibration needed to be prepared, as no isotopic effects were detected using this labeling mode. Concentrations found were in agreement with the certified concentrations (recoveries between 89% and 116%), and reproducibility was always below 7% RSD. Kragten procedure was used to calculate expanded uncertainties. Very low limits of detection were obtained for all compounds (between 0.02 and 0.9 ng·g(-1)) using the procedure developed here.     

Debromination of polybrominated diphenyl ethers by Ni/Fe bimetallic nanoparticles: influencing factors, kinetics, and mechanism

Polybrominated diphenyl ethers have been identified as a new class of organic pollutants with ecological risk due to their toxicity, bioaccumulation, and global distribution. Proper remediation technologies are needed to remove them from the environment. In this paper, Ni/Fe bimetallic nanoparticles were synthesized by chemical deposition and used to degrade decabromodiphenyl ether (BDE209). The characteristics of Ni/Fe nanoparticles were analyzed by transmission electron microscopy, X-ray diffractometry, X-ray photoelectron spectroscopy, and Brunnaer-Emmett-Teller surface area analysis. Ni/Fe bimetallic nanoparticles with diameters in the order of 20-50 nm could effectively degrade BDE209 in the solvent (tetrahydrofuran/water). Influence factors, such as Ni/Fe nanoparticle dosage, initial BDE209 concentration, and Ni loading, on the removal of BDE209 were studied. The results indicated that the degradation of BDE209 followed pseudo-first-order kinetics, and the degradation rate of BDE209 increased with increasing the amount of nano Ni/Fe particles, Ni/Fe ratio, and decreasing the initial concentration of BDE209. Through analyzed the mass balance of the BDE209 removal, degradation was the main process of BDE209 removal. The mechanism of debromination was deduced by analyzing the reaction products using gas chromatography-mass spectrometry, the bromide ion in the solution and varying the solvent conditions. Stepwise hydrogen reduction is the main process of debromination, and the hydrion play an important role in the reaction. Moreover, the experiment of long term performance and leaching of Ni were also carried out to test the stability and durability of Ni/Fe nanoparticles in BDE209 degradation.     

Synthesis and characterization of poly (aniline-co-o-anisidine-co-o-toluidine) thin films in inorganic and organic supporting electrolytes

The influence of inorganic and organic supporting electrolytes on electrochemical, optical and conducting properties of poly(aniline-co-o-anisidine-co-o-toluidine), a terpolymer thin films have been investigated. Homo and terpolymer thin films were synthesized electrochemically, under cyclic voltammetric conditions in aqueous solutions of inorganic acids, viz. H₂SO₄, HCl, HNO₃, H₃PO₄ and HClO₄ and organic acids, viz. benzoic acid, cinnamic acid, oxalic acid, malonic acid, succinic acid and adipic acid at room temperature. The films were characterized by cyclic voltammetry, UV-Visible spectroscopy and conductivity measurements using four probe technique. It was observed that the current densities are strongly influenced by the size and the nature of the anion present in the electrolyte. The optical absorption spectra indicated that the conducting emeraldine salt (ES) phase formed in all the inorganic electrolytes used, whereas it formed only in oxalic acid amongst the organic acids supporting electrolytes. The conductivity of thin films was found to be greatly affected by the nature and size of the anion present in the electrolyte. In case of terpolymer (PA-co-POA-co-POT), the conductivity lies in between the conductivity of the homopolymers PA, POA and POT, irrespective of the supporting electrolyte used. Differential scanning colorimeter (DSC) study also proved the formation of terpolymer.     

Vertical distributions and gamma dose rates of 40K, 232Th, 238U and 137Cs in the selected forest soils in Izmir, Turkey

This paper presents the results obtained from a radioecological study carried out in the selected forest sites of Izmir, Turkey. The levels of gamma-emitting radionuclides, 40K, 232Th, 238U and 137Cs, in soils were determined using gamma spectroscopy. The activity profile for 40K, 232Th and 238U exhibits a uniform distribution with respect to depth. The depth distribution of 137Cs activity was established by fitting the experimental points to an exponential or a Gaussian function. About 42-97% of the 137Cs deposition was found in the first 10 cm of soil even after 18 y from Chernobyl accident. The dose-rate and annual-effective dose received from external irradiation were quantified. It is indicated that 137Cs from the fallout plays a less role in external radiation exposures in forest sites of Izmir than in potential exposures from naturally occurring radionuclides accounted for by soil.     

Semiautomated high-throughput extraction and cleanup method for the measurement of polybrominated diphenyl ethers, polybrominated biphenyls, and polychlorinated biphenyls in human serum

A semiautomated extraction and cleanup method has been developed for the measurement of eight polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153) and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153). The method employs automated addition of internal standards ((13)C-labeled), addition of formic acid (denaturation agent), and dilution with water prior to automated overnight extraction using a modular solid-phase extraction (SPE) system. Removal of coextracted biogenic materials was performed on a two-layered 3-mL disposable cartridge containing activated silica gel and a mixture of silica gel and sulfuric acid. Sample cleanup was automated using the same modular SPE system. Reproducibility and precision of the liquid handler used for internal standard additions were shown to be 2 and 4%, respectively. Overall reproducibility during processing of eight batches of samples (N = 30/batch, including methods blanks) was below 10% for most analytes. Mean recoveries of the (13)C-labeled internal standards ranged from 69 to 95% for the seven monitored PBDEs; 76 and 98% were recovered for BB-153 and CB-153, respectively.     

Growth of epitaxial films of the organic conductor (TTF)(TCNQ)

Singly-positioned epitaxial films of the organic conductor (TTF) (TCNQ) were grown by sublimation on cleaved (100) NaCl substrates subjected to compressive stress along a 〈110〉 direction, and on polar (010) faces of ferroelectric triglycine sulfate. The conditions for obtaining thin films of this material, as well as the limitations of the epitaxial technique for obtaining large area thick films are presented and discussed.     

聚对苯二甲酰对氨基苯砜的合成与表征

以4,4’-二氨基二苯基砜(4,4’-DDS)与对苯二甲酰氯(TPC)为单体,通过低温溶液缩聚反应合成一系列不同黏度的聚对苯二甲酰对氨基苯砜。并用IR、1H-NMR、DSC、TG、电子万能实验机等对其结构和性能进行了表征和测试。实验结果表明:温度保持在-15℃,溶液质量浓度为6%时,所聚合物特性黏度最高。随着特性黏度的逐渐增大,聚对苯二甲酰对氨基苯砜的溶解性变差,玻璃化温度(Tg),热分解温度(Td)升高。弹性模量、拉伸强度等力学性能也逐渐增大。     

无卤阻燃剂间苯二酚双(二苯基)磷酸酯的合成及表征

用路易斯酸作为催化剂,用间苯二酚、三氯氧磷和苯酚作为原料合成出了间苯二酚双(二苯基)磷酸酯(RDP).研究结果表明,最好的催化剂为MgCl<,2>,并且其最佳的用量为间苯二酚用量的1%(mol).所得产物经过红外光谱、高效液相色谱和酸度的表征并对其结果进行了讨论,热失重分析表明产物的5%热失重分解温度为315℃,可作为阻燃工程塑料的阻燃荆.     

Advantages of using amorphous indium zinc oxide films for window layer in Cu(In,Ga)Se2 solar cells

The advantages of using indium zinc oxide (IZO) films instead of conventional Ga-doped zinc oxide (ZnO:Ga) films for Cu(In,Ga)Se₂ (CIGS) solar cells are described. The electrical properties of IZO are independent of film thickness. IZO films have higher mobility (30-40 cm²/Vs) and lower resistivity (4-5 × 10^− 4 Ω cm) compared to ZnO:Ga films deposited without intentional heating, because the number of grain boundaries in amorphous IZO films is small. The properties of a CIGS solar cell using IZO at the window layer were better than those obtained using a conventional ZnO:Ga at the window layer; moreover, the properties tended to be independent of thickness. These results indicate that use of IZO as a transparent conducting oxide layer is expected to increase the efficiency of CIGS solar cells.     

Application of tosylate-doped poly(3,4ethylenedioxythiophene) (PEDOT) films into bottom contact pentacene organic thin film transistors (OTFTs)

The effect of iron(III) p-toluenesulfonate hexahydrate (Fe(PTS)₃) concentration on the formation and patternability of poly(3,4ethylenedioxythiophene) (PEDOT) films on (3-aminopropyl)trimethoxysilane (APS) monolayer was investigated. Low deposition rate yielded highly conductive and very smooth PEDOT films. However, the spin-coated oxidants in low Fe(PTS)₃ concentrations were susceptible to moistures, leading to the poorly patterned PEDOT films. Increasing Fe(PTS)₃ concentration enabled the fine patterning of the films. The fabricated thin film transistors with PEDOT electrodes formed on 30 wt.% Fe(PTS)₃ revealed the saturation mobility of 0.16 cm²/V s and subthreshold slope of 0.5 V/decade. The obtained low contact resistance was 12 kΩ cm, possibly due to the negligible interface morphological discontinuity at the pentacene-PEDOT interface.     

Characteristics of polycyclic aromatic hydrocarbons and total suspended particulate in indoor and outdoor atmosphere of a Taiwanese temple

Incense burning, a common and popular practice among many families and in most temples in Taiwan, can result in indoor pollution-related health problems. This exploratory study was aimed at characterizing human exposure to polycyclic aromatic hydrocarbons (PAHs) and total suspended particulate (TSP) inside and around a Taiwanese temple, and to compare the indoor levels with levels outside. Additionally, three types of commonly used unburned incense and incense ash were analyzed in order to evaluate the relationship between incense composition and PAH emissions.Standard methods were used to determine air concentrations of 21 PAHs and TSP inside and around a chosen temple. Indoor mean total-PAH concentration, particle-bound PAH concentration and TSP concentration were 6258 ng/m(3), 490 micro g/g and 1316 micro g/m(3), respectively; values for outdoor readings were 231 ng/m (3), 245 micro g/g and 73 micro g/m(3), for outdoors, respectively indicating PAH and TSP concentrations inside 27 and 18 times greater, respectively than outdoors. With respect to concentrations of individual PAHs (particulate+gas phase), the five highest concentrations were of acenaphthylene (AcPy) (3583 ng/m(3)), naphthalene (Nap) (1264 ng/m(3)), acenaphthene (Acp) (349 ng/m(3)), fluoranthene (FL) (243 ng/m(3)) and phenanthrene (PA) (181 ng/m(3)). Median values for indoor/outdoor (I/O) ratios of individual PAHs ranged from 5.7 to 387.9, which implied that the temple was a significant PAH source. Moreover, PAH content of the tested stick incense and ash was very low. PAH levels inside the temple were much higher than those measured in the vicinity and inside residential houses; and were in fact close to levels measured at a local traffic intersection in Tainan, Taiwan, and those in a graphite-electrode producing plant during the graphitization process. It is obvious that such substantially high concentrations of PAHs and TSP constitute a potential health hazard to people working in or visiting the temple.     

Vertical distribution of (226)Ra and (210)Po in agricultural soils in Buyuk Menderes Basin, Turkey

The vertical distribution of (226)Ra and (210)Po was investigated in the cultivated soils of the Buyuk Menderes Basin in Turkey. Five soil cores down to a depth of about 50 cm were taken from each site and divided into strata of 2-3 cm intervals. The samples were analyzed for their (226)Ra and (210)Po activity concentrations using radioanalytical methods. Down-core concentration profiles of (226)Ra and (210)Po in the soil cores from five sites are obtained. The activity concentrations of soil cores range from 80 to 1170 Bq kg(-1) for (226)Ra and from 10 to 870 Bq kg(-1) for (210)Po with the depth. Analysis of the vertical soil profiles indicate that the activity concentrations of (226)Ra and (210)Po for soil strata at all the sites have not extremely changed with depth.     

Radiological maps of outdoor and indoor gamma dose rates in Greek urban areas obtained by in situ gamma spectrometry

The results obtained from 259 indoor and outdoor in situ gamma spectrometry measurements with a portable Ge detector and 707 total gamma dose rate measurements with an NaI detector in urban areas of 16 Greek islands are presented. From the in situ gamma spectra, the absorbed dose rate in air due to Uranium series, Thorium series, (40)K and (137)Cs are derived and discussed. The results obtained from the present work in conjunction with those reported previously were used for the realization of a complete indoor and outdoor gamma radiation map of Greek urban areas using in situ gamma spectrometry with portable Ge detector.     

Transparent, conductive, and flexible carbon nanotube films and their application in organic light-emitting diodes

We have carried out comparative studies on transparent conductive thin films made with two kinds of commercial carbon nanotubes: HiPCO and arc-discharge nanotubes. These films have been further exploited as hole-injection electrodes for organic light-emitting diodes (OLEDs) on both rigid glass and flexible substrates. Our experiments reveal that films based on arc-discharge nanotubes are overwhelmingly better than HiPCO-nanotube-based films in all of the critical aspects, including surface roughness, sheet resistance, and transparency. Further improvement in arc-discharge nanotube films has been achieved by using PEDOT passivation for better surface smoothness and using SOCl2 doping for lower sheet resistance. The optimized films show a typical sheet resistance of approximately 160 Omega/ square at 87% transparency and have been used successfully to make OLEDs with high stabilities and long lifetimes.     

Semiautomated high-throughput extraction and cleanup method for the measurement of polybrominated diphenyl ethers and polybrominated and polychlorinated biphenyls in breast milk

A semiautomated extraction and cleanup method has been developed to measure eight polybrominated diphenyl ethers (PBDEs), 2,2',4,4',5,5'-hexabromobiphenyl (BB-153), and 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153). The method employs solid-phase dispersion on diatomaceous earth in a solid-phase extraction cartridge followed by automated addition of internal standards ((13)C-labeled). Extraction is then performed using an automated modular solid-phase extraction system. The extraction procedure includes drying the sample on diatomaceous earth by pressurized nitrogen and eluting target analytes and lipids with dichloromethane. Lipid content is determined gravimetrically. Lipid determinations performed using this method are compared with other standard methods and with a certified reference material. A relative standard deviation of 7.9% was obtained for 130 determinations of the lipid content in a breast milk quality control sample. Final analytical determination of target analytes was performed by gas chromatography-isotope dilution high-resolution mass spectrometry. Relative standard deviations for the measurements of target analytes for which a labeled internal standard was available were below 10% for analytes at concentrations above 1 ng/g of lipid. Mean recoveries of the (13)C-labeled internal standards ranged from 60 to 89% for the eight PBDE congeners; 74 and 113% were recovered for BB-153 and CB-153, respectively.