Sea to Air Flux of Dimethyl Sulfide and Its Effect on the Environment

Reviews on the cunent studies on the sea to air flux ofdimethyl sulfide (DMS) have been made at home and abroad, pointing out that the flux of DMS is influenced by many factors.There is great difference between the results coming fiom different models. Besides, this paper focuses on the oxidation mechanisms of DMS by OH and NO3 radicals after it enters the atmosphere, the oxidation products' contribution to acid rain and fog and the relationships among the DMS, CCN and climate system.     

硫代甜菜碱(DMSP)对大气环境的影响及其对水产动物营养的促进作用

一种二甲基硫化合物硫代甜菜碱（DMSP）成为环境科学和水产科学共同关注的热点之一。研究表明，DMSP是海洋植物产生的渗透调节物质，大量存在于海藻和盐生高等植物体内。含有DMSP的生物体死亡之后，DMSP被海洋细菌的二甲硫醚生成酶降解，生成二甲硫醚（DMS）和丙烯酸。DMS从海洋水面逾出，进入大气形成酸雨；由于DMS能形成云，所以有降低温室效应的作用。DMSP本身则对哺乳动物、禽类及水产动物（鱼和虾）的营养代谢有促进作用。酶学研究表明，动物肝脏中的两种硫甲基转移酶能把DMSP分子中硫原子上的甲基转换出来，提供给机体代谢所需。作为海洋植物渗透调节物质的主要成分，DMSP来源于植物体内的蛋氨酸。研究DMSP的生成变化规律，对进一步了解海洋气候和开发使用新的水产动物饲料添加剂有重要价值。     

Laboratory-scale evaluation of the potential of chemical containment for farmed abalone larval escapees

The sensitivity of abalone Haliotis midae larvae to low levels of toxicants was used to conduct a laboratoryscale experiment to determine the possibility of using chemical containment to prevent the escape of larvae from land-based culture systems, thereby reducing the environmental impact of farming operations. The cryoprotective agent, dimethyl sulphoxide or DMSO (Me₂SO), was used as a toxicant and embryos were exposed to increasing concentrations (0–25.60 mol l^–1) of DMSO for a period of 24 hours. Hatch-out rates of the control group (0.0% DMSO) did not differ from those obtained at 0.2% (2.56 mol l^–1) and 0.4% (5.12 mol l^–1) DMSO. An exposure level at and above 0.6% DMSO resulted in a significant decrease in the number of normal larvae. At an exposure concentration of 0.6% (7.68 mol l^–1) DMSO, 65% (SE 3.0) of the fertilised eggs hatched, compared to only 10% (SE 2.0) at a concentration of 1.0% (12.80 mol l^–1) DMSO. This study indicates the potential for use of DMSO as a form of chemical containment of abalone larvae, even at very low doses. It presents South African abalone farms with a chemical containment method that could potentially be used to prevent the unintentional escape of H. midae larvae from land-based operations.     

原位微区X射线荧光光谱分析装置与技术研究进展

原位微区X射线荧光(Micro-XRF)光谱分析技术是X射线光谱学领域一重要分支。近年来X射线毛细管光学透镜聚焦技术不断进步,以实验室X光源为基础的原位微区X射线光谱分析装置与应用技术快速发展,已成功应用于多领域样品的原位、多维、动态和非破坏性微区分析。文章介绍了近年来X射线毛细管光学透镜技术发展和原位微区X射线光谱分析装置研制进展,对近年来micro-XRF光谱分析技术在大气气溶胶颗粒物分析与来源识别、考古样品产地和真伪鉴别、古气候古环境重建研究中沉积纹层样品元素分析,以及刑侦科学中指纹样品的鉴定等应用领域进行了系统介绍,阐述了micro-XRF光谱分析技术性能的影响因素(空间分辨率和强度增益)。micro-XRF光谱分析技术不仅可以获取样品表面的信息,还能够获取样品内部的信息,成为目前国际上一门迅速发展的竞争技术。我国在毛细管透镜制造技术与性能研究,以及micro-XRF应用领域取得了重要进展。由于X射线焦斑尺寸对能量的依赖性以及样品基质对X射线的吸收效应,在微区定量分析中易引入较大误差,利用X射线毛细管透镜获取更小光斑尺寸与高稳定性的X射线光束,提高micro-XRF分析技术的空间高分辨率性能和对基体效应进行校正实验将是今后一个重要的研究目标和分析研究难点。     

Sulfur dioxide and dimethyl sulfide in the central Pacific troposphere

Boundary-layer and free-troposphere measurements of sulfur dioxide, dimethyl sulfide, and carbon disulfide were made during transits of the central and southern Pacific Ocean between Hawaii and Australia. Sulfur dioxide was generally less than 100 pptv and highly variable with no correlation with respect to geographic location or altitude. Dimethyl sulfide in the boundary layer had a concentration range of <10 to 200 pptv. Highest concentrations of DMS were in the equatorial region of the southern hemisphere although the concentrations were dependent on location and meteorological regime. In the region of the Fiji Islands several boundary layer samples had SO₂, DMS, and CS₂. In 1989, additional SO₂ measurements were made between Hawaii and the equator and to the west of Hawaii downwind of the Kilauea volcano plumes.Paper submitted to the 7th International Symposium of the Commission for Atmospheric Chemistry and Global Pollution on the Chemistry of the Global Atmosphere held in Chamrousse, France, from 5 to 11 September 1990.     

二甲基黄褪色光度法测定地质样品中痕量锰

由ＭｎＯ＾－４氧化二甲基黄使基褪色原理分光光度法测定痕量Ｍｎ。在０．３６－２．８８ｍｏｌ／ＬＨ２ＳＯ４介质中，Ｍｎ量在０－１．６μｇ／ｍｌ时与二甲基黄褪色的程度呈线性关系，吸光度至少保持２ｈ不变。方法比通常的ＭｎＯ＾－４比色法灵敏度高１０倍，用于测定地质样品中的痕量Ｍｎ时，结果满意。     

皱纹盘鲍脂肪酸及脂肪醛二甲基缩醛的气相色谱/质谱分析

研究了用气相色谱/质谱法测定皱纹盘鲍中脂肪酸及脂肪醛二甲基缩醛的方法。皱纹盘鲍经Folch法提取总脂,用10%硫酸-甲醇溶液进行反应,通过气相色谱/质谱法对其脂肪酸及脂肪醛二甲基缩醛的组成进行分析。实验结果表明:10%硫酸-甲醇溶液能有效地对脂肪酸进行甲酯化衍生;同时促使烯醚键断裂,并与甲醇发生缩醛反应生成脂肪醛二甲基缩醛。通过气相色谱/质谱分析,从皱纹盘鲍中共鉴定出32个化合物,包括26种脂肪酸和6种脂肪醛二甲基缩醛;脂肪酸以C16:0、C20:4(n-6)、C20:5(n-3)、C18:1(n-7)和C22:5(n-3)为主;脂肪醛二甲基缩醛以C18:0DMA和C20:1DMA为主。皱纹盘鲍肌肉和内脏中的脂肪酸及脂肪醛二甲基缩醛的组成基本一致,但内脏中的4,8,12-三甲基十三烷酸含量远高于肌肉,具有极显著差异(P<0.01)。     

Occurrence of phthalate diesters in rivers of the Paris district (France)

The occurrence and fate of six phthalate esters were investigated in the River Seine and two tributaries in the Paris area, at six sites from upstream to downstream, throughout different seasons, with special attention given to a flood episode. At all sites, except the River Marne, whatever the period, diethylhexyl phthalate (DEHP) displayed the highest concentration (0·323–0·779 µg l^?1 as mean values), followed by di‐n‐butyl phthalate (DnBP; 0·211–0·526 µg l^?1 as mean values), which is consistent with the production pattern. High phthalate concentrations appeared to be related to population density and industrial distribution. The strongest values were located downstream from wastewater treatment plant effluent inputs. Seasonal variations were closely related to river flow and air and water temperature. The annual evolution of phthalates was linked to the hydrological conditions. During the flood episode at Paris, the DEHP concentration displayed a sharp increase (260 to 1123 ng l^?1) occurring 9 days before the flood peak. The simultaneous fluctuations of NH₄, typical of domestic origin, and of DEHP suggests a similar origin from combined sewer overflows for both compounds. Other elevated values corresponded to the highest precipitation amounts, and demonstrated the contribution of non‐point‐source runoff and wastewater overflow to DEHP inputs. The DEHP concentration relationship with river flow displayed a clockwise hysteresis loop, corresponding to a ‘first‐flush’ effect in which the finite supplies are swept along in the early stage of the flood. Annual fluxes for 2004 at Paris were 2257 kg of DEHP and 1613 kg of DnBP. The flood period seemed to have a minor impact on annual phthalate transport (29·5% and 41% of the total for DEHP and for DnBP, respectively), which is contrary to annual suspended solids transport (69%). Copyright © 2007 John Wiley & Sons, Ltd.     

Occurrence of phthalate esters in the Seine River estuary (France)

The rigin and fate of six phthalate esters (dimethyl phthalate (DMP), diethyl phthalate (DEP), di‐n‐butyl phthalate (DnBP), butyl benzyl phthalate (BBP), di (2‐ethylhexyl) phthalate (DEHP) and di‐n‐octyl phthalate (DnOP)), were investigated during 2005 and 2006 in the densely populated Seine river estuary. Four compounds, DMP, DEP, DnBP and DEHP were detected at all the stations with DEHP (160–314 ng L^?1), followed by DEP (71–181 ng L^?1) and next DnBP (67–319 ng L^?1), except at la Bouille, where DnBP was the second most important compound. BBP and DnOP concentrations remained low and were not found at all the stations. Considering all six phthalates, Caudebec‐en‐Caux (beginning of the salinity gradient) was the least polluted station (464 ng L^?1), whereas Honfleur (771 ng L^?1) and La Bouille (716 ng L^?1) displayed the highest contamination levels, probably related to important industrial plants. From Caudebec‐en‐Caux to Honfleur (maximum turbidity), variation of DEHP concentration was related to that of suspended matter. In addition, the salinity rise in that area might have facilitated DEHP sorption upon particles. A significant correlation between flow magnitude and DEHP concentration was found (P < 0·01, n = 12), supporting the influence of the hydrological cycle upon contamination. Runoff contribution (56·9 kg d^?1) to river contamination was confirmed by the annual evolution of phthalate concentrations in the Seine river at Poses. Concentrations of DEHP in the tributaries were in the same range as those of the Seine River (100–350 ng L^?1), except for two in densely populated and industrialized areas: Robec (800 ng L^?1) and Cailly (970 ng L^?1). The treatment plant discharge fluxes were in the same range as those of tributaries (30·4–250 g d^?1). During high flow periods, the influence of tributaries and of treatment plants seemed to play a minor part in the contamination level of the Seine river estuary. Copyright © 2009 John Wiley & Sons, Ltd.     

气雾剂二甲醚中三甲胺的气相色谱分析

采用CP-PoraPLOT Am ines色谱柱,火焰离子化检测器(FID),气相色谱法对二甲醚中三甲胺进行定性、定量分析。操作简单,与自动取样阀连用可实现在线监测。结果表明,在不需富集的情况下检出限可达0.51×10-6(体积分数),回收率为98%~103%,相对标准偏差(RSD,n=7)为1.07%,完全满足工业在线监测的需要。