Elevated tri(n-butyl)tin concentrations in shellfish and sediments from Suva Harbour,Fiji

Tri(n-butyl)tin (TBT) concentrations were determined in sediments and selected shellfish from Suva Harbour, Fiji. Sediments in the immediate vicinity of foreshore slipways and boatyards were exceedingly contaminated, with a maximum observed level of 38μ g^?1 TBT-Sn. Concentrations were much lower in surficial sediments from commercial docks and yacht mooring areas, namely 16–83 ng g^?1 TBT-Sn. Mangrove oysters (Crassostrea mordax), gastropods (Thais mancinella), and bivalves (Anadara scapha) were found to have accumulated TBT. Concentrations as high as 3180 ng g^?1 TBT-Sn were found in mangrove oysters. With respect to the mangrove oyster, its widespread distribution, abundance and proclivity to accumulate TBT suggest that it is likely to be the best bioindicator species of TBT contamination in Fijian coastal waters.     

开都河——孔雀河流域水资源综合利用优化管理模型

根据开都河——孔雀河流域水资源系统的特点 ,从系统分析的角度出发 ,综合考虑水利 ,水电及生态环境保护工程效益 ,提出了一个多目标优化管理模型 .该模型能模拟实际系统的运行 ,还具有良好的扩展性 ,为科学治理保护开都河——孔雀河流域提供了可靠的科学依据 .     

Butyltin speciation in sediments and biological samples by hydride generation gas chromatography quartz furnace atomic absorption spectrometry; a study of acid leaching procedures and hydride generation

The efficiency of the extraction of butyltin compounds from sediments and biological matter by acid leaching procedures has been evaluated on real samples using the hydride generation gas chromatography quartz furnace atomic absorption (GC AA) speciation method. The most efficient method uses cold pure acetic acid over a period of four hours. Hydride generation using sodium tetrahydroborate (NaBH₄) is dependent on matrix composition and care must be taken to adapt the amount of reactant to the organic content of the sample.     

THE RESEARCHES OF GLACIER LAKE OUTBURST FLOODS OF THE YARKANT RIVER IN XINJIANG

The Jokulhlaup of the Yarkant River (Yarkant He) is usually csused by the sudden discharge of the glacier-dammed lake and the mode of the discharge is the rapid expansion of the subglacial channel. Keyajir (Kyagar) Glacier and Telamukanli Glacier are on the upper reaches of the Keleqin (Shaksgam) River, the chief birthplaces of this kind of flood. Up to the end of this century, since the global climate has become warmer, the glaciers have accordingly shrunk and become thinner, with the result that the size and dimensions of the glacier-dammed lakes and their outburst floods have diminished. All these simply reveal the mystery of the Jokulhlaups of the Yarkant River in Xinjiang.     

咸化湖盆过渡相组沉积控储作用浅析

咸化湖盆过渡相组（三角洲前缘与浅湖亚相）沉积特征与淡水湖盆存在显著差异,尤其在骨架砂体微相类型、分布等方面。研究其沉积控储机制,既是对湖盆沉积学理论的重要发展,也对中国陆相盆地碎屑岩油气勘探开发具有实际指导意义。应用大量岩芯、测录井及铸体薄片资料,分析了柴达木盆地英东地区下油砂山组（N₂¹）与上油砂山组（N₂²）三角洲前缘浅湖沉积特征及优质储层形成主控因素。研究表明,咸化湖盆三角洲前缘浅湖主要发育水下分流河道与滩坝两种储集砂体沉积微相类型。两者在沉积构造、粒度分布、微观组构及测井曲线叠加样式等方面存在显著差异。沉积微相是优质储层形成的物质基础,与湖盆水体咸化程度共同控制了优质储层的分布。咸化湖盆碎屑岩储层整体成分成熟度偏低,以原生孔隙为主,溶蚀作用较弱,次生孔隙相对欠发育。强烈的早成岩期碳酸盐胶结作用增加了岩石的抗压能力。储层物性主要受控于岩石粒度与胶结物含量。     

Ultrasound‐assisted extraction method for the simultaneous determination of emerging contaminants in freshwater sediments

Sediments are the fate of several emerging organic contaminants, such as pharmaceuticals, personal care products and hormones, and therefore an important subject in environmental monitoring studies. In the present work, a simple and sensitive method was developed, validated and applied for the simultaneous extraction of atenolol, caffeine, carbamazepine, diclofenac, ibuprofen, naproxen, propranolol, triclosan, estrone, 17‐β‐estradiol and 17‐α‐ethinylestradiol using ultrasound‐assisted extraction from freshwater sediment samples followed by solid‐phase extraction clean‐up and liquid chromatography with tandem mass spectrometry detection. The solvent type and extraction pH were evaluated to obtain the highest recoveries of the compounds. The best method shows absolute recoveries between 54.0 and 94.4% at 50 ng/g concentration. The method exhibits good precision with relative standard deviation ranging from 1.0–16%. The detection and quantification limits ranged from 0.006–0.067 and 0.016–0.336 ng/g, respectively. The developed method was successfully applied to freshwater sediment samples collected from different sites in Jundiaí River basin of São Paulo State, Brazil. The compounds atenolol, caffeine, propranolol and triclosan were detected in all the sampling sites with concentrations of 13.8, 41.0, 28.5 and 176 ng/g, respectively.     

Determination of methylmercury in marine sediment samples: Method validation and occurrence data

The determination of methylmercury (MeHg) in sediment samples is a difficult task due to the extremely low MeHg/THg (total mercury) ratio and species interconversion. Here, we present the method validation of a cost-effective fit-for-purpose analytical procedure for the measurement of MeHg in sediments, which is based on aqueous phase ethylation, followed by purge and trap and hyphenated gas chromatography–pyrolysis–atomic fluorescence spectrometry (GC–Py–AFS) separation and detection. Four different extraction techniques, namely acid and alkaline leaching followed by solvent extraction and evaporation, microwave-assisted extraction with 2-mercaptoethanol, and acid leaching, solvent extraction and back extraction into sodium thiosulfate, were examined regarding their potential to selectively extract MeHg from estuarine sediment IAEA-405 certified reference material (CRM). The procedure based on acid leaching with HNO₃/CuSO₄, solvent extraction and back extraction into Na₂S₂O₃ yielded the highest extraction recovery, i.e., 94 ± 3% and offered the possibility to perform the extraction of a large number of samples in a short time, by eliminating the evaporation step. The artifact formation of MeHg was evaluated by high performance liquid chromatography coupled to inductively coupled plasma mass spectrometry (HPLC–ICP–MS), using isotopically enriched Me²⁰¹Hg and ²⁰²Hg and it was found to be nonexistent. A full validation approach in line with ISO 17025 and Eurachem guidelines was followed. With this in mind, blanks, selectivity, working range (1–800 pg), linearity (0.9995), recovery (94–96%), repeatability (3%), intermediate precision (4%), limit of detection (0.45 pg) and limit of quantification (0.85 pg) were systematically assessed with CRM IAEA-405. The uncertainty budget was calculated and the major contribution to the combined uncertainty (16.24%, k = 2) was found to arise from the uncertainty associated with recovery (74.1%). Demonstration of traceability of measurement results is also presented. The validated measurement procedure was applied to the determination of MeHg incurred in sediments from a highly polluted and scarcely studied area in the Caribbean region.     

ASE/GC-MS法同时测定海洋沉积物中65种多氯联苯、多环芳烃与有机氯农药

建立了加速溶剂萃取/气相色谱-质谱法(ASE/GC-MS)同时测定海洋沉积物中28种多氯联苯(PCBs)、16种多环芳烃(PAHs)和21种有机氯农药(OCPs)的分析方法.结果表明,ASE的最佳萃取温度为100 ℃,最佳静态时间为5 min.GC-MS同时分析65种化合物时,PAHs的线性范围为0.05 ～5.00 ...     

鼠伤寒沙门氏菌在长春南湖水体中的存活

鼠伤寒沙门氏菌是著名的致病菌,并能够在湖水等多种环境中存活。人类可能通过食用携带病菌的食物或接触含有病菌的水体等多种方式遭受它们的入侵。因此,实验旨在研究沙门氏菌在水体中的存活规律,为保障公众健康提供依据。将沙门氏菌接种到采于长春市南湖水体的10个水样中进行培养,并使用Weibull分布模型和线性模型模拟沙门氏菌的存活动态,同时分析了水体理化性质对细菌存活的影响。Weibull模型拟合沙门氏菌在10个水样中的存活时间分布在9.44~27.94 d之间,而线性模型拟合结果在9.27~23.01 d之间。研究表明,鼠伤寒沙门氏菌的存活时间与水样电导率(electrical conductivity,EC)成正相关关系。在一定范围内,随着电导率的增加,细菌存活时间也有所增加。