生物降解有机卤化物

近来，从一些可利用卤化底物的细菌中分离出了新的去卤化酶，利用X衍射分析和序列分析已揭示出水解去卤化酶的分子机制。另外，基因和生物化学研究还发现，还原去卤化酶是胞外含咕啉化合物的铁硫蛋白；序列分析和突变研究表明，这些去卤化酶相对那些可转化非卤化底物的酶是同源的。     

Adsorption Behavior of Halogenated Anesthetic and Water Vapor on Cr‐Based MOF (MIL‐101) Adsorbent. Part I. Equilibrium and Breakthrough Characterizations

A synthesized chromium‐based metal organic framework (Cr‐MOF) was used for the adsorption of halogenated anesthetics, i.e., sevoflurane (SF). Adsorption isotherm and breakthrough experiments involving SF (reference sorbate) and water vapor were measured at 298 K and atmospheric pressure on both Cr‐MOF and a commercially used reference adsorbent. The Cr‐MOF MIL‐101 showed a significantly higher SF adsorption capacity and much higher selectivity relative to water vapor compared to the reference adsorbent. Binary‐mixture breakthrough tests demonstrated a “roll‐up effect” for SF on the reference adsorbent while no such effect was observed on MIL‐101.     

羧酸及羧酸盐与卤代烃直接合成酯的研究

羧酸及羧酯盐在三乙胺或三乙胺与碘化钠存在下，直接与卤代烃进行酯化反应，在最佳工艺条件下可得到较高的酯收率。文中叙述了这种方法的几个典型实例。     

DNA damage induction by two halogenated acetaldehydes, byproducts of water disinfection

Drinking water contains disinfection byproducts, generated by the interaction of chlorine (or other disinfecting chemicals) with organic matter, anthropogenic contaminants, and bromide/iodide naturally present in most source waters. One class of these chemicals is the halogenated acetaldehydes (HAs), identified in high quantities when ozone is used as primary or secondary disinfectant. In this study, an analysis of the genotoxic potential of two HAs, namely tribromoacetaldehyde (TBA) and chloral hydrate (CH) has been conducted in human cells (TK6 cultured cells and peripheral blood lymphocytes). The comet assay was used to 1) measure the induction of single and double-strand DNA breaks, 2) evaluate the capacity of inducing oxidative DNA damage, and 3) determine the DNA repair kinetics of the induced primary genetic damage. In addition, chromosome damage, as a measure of fixed damage, was evaluated by means of the micronucleus test. The results of the comet assay show that both compounds are clearly genotoxic, inducing high levels of DNA breaks, TBA being more effective than CH. According to the comet results, both HAs produce high levels of oxidized bases, and the induced DNA damage is rapidly repaired over time. Contrarily, the results obtained in the micronucleus test, which measures the capacity of genotoxic agents to induce clastogenic and aneugenic effects, are negative for the two HAs tested, either using TK6 cells or human peripheral blood lymphocytes. This would indicate that the primary damage induced by the two HAs is not fixed as chromosome damage, possibly due to an efficient repair or the death of damaged cells, which is an important point in terms of risk assessment of DBPs exposure.     

Clicking ferrocene to halogenated boron-doped diamond surfaces

The halogenated boron-doped diamond (BDD) surfaces were reacted with sodium azide through a nucleophilic substitution reaction. The resulting azide-terminated BDD surfaces were used to trigger the "click" reaction. Because of the attractive electrochemical properties of ferrocene-containing molecules, such as fast electron transfer rates, reversible redox activities, and favorable redox potentials, we show that ferrocene derivatives can be grafted onto non-oxidized diamond surfaces by click"chemistry". These redox-active ferrocene-containing layers on a BDD surface, because of their ability to store and release charges reversibly, have the potential to be used as hybrid molecular/semiconductor memory devices.     

Evaluation of the occurrence and biodegradation of parabens and halogenated by-products in wastewater by accurate-mass liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-QTOF-MS)

An assessment of the sewage occurrence and biodegradability of seven parabens and three halogenated derivatives of methyl paraben (MeP) is presented. Several wastewater samples were collected at three different wastewater treatment plants (WWTPs) during April and May 2010, concentrated by solid-phase extraction (SPE) and analysed by liquid chromatography-electrospray-quadrupole-time-of-flight mass spectrometry (LC-QTOF-MS). The performance of the QTOF system proved to be comparable to triple-quadrupole instruments in terms of quantitative capabilities, with good linearity (R² > 0.99 in the 5-500 ng mL⁻¹ range), repeatability (RSD < 5.6%) and LODs (0.3-4.0 ng L⁻¹ after SPE). MeP and n-propyl paraben (n-PrP) were the most frequently detected and the most abundant analytes in raw wastewater (0.3-10 μg L⁻¹), in accordance with the data displayed in the bibliography and reflecting their wider use in cosmetic formulations. Samples were also evaluated in search for potential halogenated by-products of parabens, formed as a result of their reaction with residual chlorine contained in tap water. Monochloro- and dichloro-methyl paraben (ClMeP and Cl₂MeP) were found and quantified in raw wastewater at levels between 0.01 and 0.1 μg L⁻¹. Halogenated derivatives of n-PrP could not be quantified due to the lack of standards; nevertheless, the monochlorinated species (ClPrP) was identified in several samples from its accurate precursor and product ions mass/charge ratios (m/z). Removal efficiencies of parabens and MeP chlorinated by-products in WWTPs exceeded 90%, with the lowest percentages corresponding to the latter species. This trend was confirmed by an activated sludge biodegradation batch test, where non-halogenated parabens had half-lives lower than 4 days, whereas halogenated derivatives of MeP turned out to be more persistent, with up to 10 days of half-life in the case of dihalogenated derivatives. A further stability test performed with raw wastewater also showed that parabens degrade rapidly in real sewage, with half-lives lower than 10 h for n-butyl-paraben, while dihalogenated species again turned out to be more stable, with half-lives longer than a week.     

Quantitative GC-ECD Analysis of Halogenated Metabolites: Determination of Surface and Within-Thallus Elatol of Laurencia obtusa

Information on natural concentrations or variability of secondary metabolites in marine organisms may be important both to ecological/evolutionary and applied approaches. A gas chromatographic procedure with an electron capture detector (GC-ECD) was developed to quantify the sesquiterpenoid elatol at the surface and within-thalli of 70 specimens of the red seaweed Laurencia obtusa. The concentration of elatol was highest within-thalli [9.89 mg g⁻¹ of L. obtusa, dry weight (d.w.)], compared to lower values found at the surface [0.006 mg g⁻¹ of L.obtusa (d.w.), or 0.5–10.0 ng cm⁻²]. This method provides a rapid and inexpensive quantification of small quantities of elatol, and probably may also be used to quantify other halogenated compounds usually found in red seaweeds.     

阻燃剂V6的合成及其在聚氨酯中的应用

以季戊四醇、三氯化磷、氯气及环氧乙烷为原料，四氯化钛为催化剂，通过三步反应合成了阻燃剂v6，总产率达93．5％。用FT-IR、1^HNMR、MS以及元素分析等手段对目标产物及其中间体进行了表征，并将其用于阻燃聚氨酯泡沫塑料。实验发现，阻燃剂v6对聚氨酯泡沫塑料有较好的阻燃效果，最佳添加量为20％。     

一种新型的无色染料的PVG剂量膜

新研制的无色染料剂量膜可测试＾６０Ｃｏγ辐射的剂量，定名为ＰＶＧ剂量膜，它用基料膜乙烯醇缩丁醛（ＰＶＢ）、无色孔雀缘（ＬＭＧ）和添加剂卤化物（ＲＸ）加工而成，剂量范围０．５～８０ｋＧｙ，在６２７ｎｍ处其吸收（△Ａ／Ｌ）与剂量的关系呈线性（相关系数ｒ〉０．９９９），温度校正系数＋０．０５３／℃，相对湿度（ｒ．ｈ）在０～９６．４％范围内，其剂量响应随相对湿度的增加而增加，其校正系数为＋０．００６／△ｒ