毛细管气相色谱法测定海洋沉积物中饱和烷烃

一、前言 海洋沉积物中饱和烃来源于人为石油烃污染、海洋生物和陆源高等植物。因此海洋沉积物中的饱和烃组成较复杂,含有n-C_(14)—n-C_(36)的正构烷烃和异构烷烃等,沸点范围很宽。用常规填充柱气相色谱难于分离这样复杂的饱和烃。毛细管气相色谱与之相比,具有较高的分离效能,比较适用于测定海洋沉积物中的饱和烃。通过饱和烃含量的测定,可鉴别其是人为     

高分子量烃在海洋油气地球化学探测中的应用

高分子量烃主要包括饱和烃和不饱和烃两大类,是石油的主要组成部分。用于海底沉积物高分子量烃测量的主要方法有全萃取气相色谱、全扫描荧光和气相色谱/质谱或气相色谱/质谱/质谱等。全萃取气相色谱能够给出总萃取有机物、不溶复杂化合物、总链烃的量,指示热成因和新近有机物的贡献;全扫描荧光能够给出最大荧光强度、最大发射波长、最大激发波长、R值和指纹图形状等信息,不仅能够指示热成因烃和新近有机物的贡献,而且能够指示油气属性和含油气性;气相色谱/质谱或气相色谱/质谱/质谱测量海底沉积物中生物标志物组成特征,识别海底烃类渗漏的存在,给出渗漏烃源区源岩特征、热成熟度、成烃时代以及油质等信息。     

海洋溢油鉴别前处理技术比较研究

针对目前海洋溢油样品的吸附色谱柱预分离前处理技术,比较了不同前处理方法得到的溢油样品中烃类化合物、生物标志物、金刚烷类化合物和多环芳烃类化合物的气相色谱／气相色谱质谱指纹图谱。就溢油样品吸附色谱柱预分离技术的优缺点进行了详细总结和讨论,并为溢油来源的快速、准确鉴别提出了建议。     

我国几种常见润滑油的指纹分析

采用气相色谱／质谱方法（GC／MS）对7种常见润滑油中的生物标志化合物（正构烷烃、姥鲛烷、植烷、甾烷、萜烷、多环芳烃）进行定性分析,并基于其生物标志化舍物指纹信息进行了多元统计分析。结果表明,润滑油的气相色谱图中不可分辨的混合物（UCM）具有明显优势;润滑油中含有丰富的甾、萜烷类稠环生物标志化合物,仅含有非常少量的饱和...     

水环境及水产品中汞的测定与形态分析进展

概要总结了世界各地对水环境及水产品中汞的测定与形态分析的研究成果,涵盖样品采集、储存、传递与处理,各种色谱(薄层色谱、气相色谱、液相色谱、电色谱和离子色谱)分离分析方法及其联用技术,以及分光光度法、电化学法、原子吸收光谱和原子荧光光谱的应用等。并对未来发展提出了改进建议。     

海水悬浮物浓度原位测量技术进展

海水悬浮物指海水中的悬浮颗粒物和浮游微生物等，对海水悬浮物浓度进行准确的测量具有重要的意义。海水悬浮物浓度测量技术，无论是传统方法（即现场采水），还是现代方法（即间接测量方式，包括光学法和声学法等）都有一定的不足。本文主要综述了几种海水悬浮物浓度间接测量方法、国内外有关海水原位过滤测量的技术研发进展及深海原位微孔过滤技术。最后，对海水悬浮物原位过滤技术的发展方向进行了探讨。     

海洋细菌脂肪酸的气相色谱分析

以副溶血性弧菌VP-X-3为试验对象,利用气相色谱技术分析了其细胞脂肪酸的组成和含量,以色谱峰的数量、色谱峰高及脂肪酸含量作为评价指标,探讨了不同的皂化和甲酯化条件对细菌细胞脂肪酸测定结果的影响。结果表明:皂化和甲酯化条件都对细胞脂肪酸的组成和含量产生一定的影响。较低温度皂化处理利于增加色谱峰数量和色谱峰高。甲酯化温度过高容易破坏脂肪酸,尤其是长链脂肪酸和不饱和脂肪酸的结构。高温甲酯化条件下,时间越长,甲酯化效果越差。试验得到较为理想的气相色谱前处理条件:2 mol/L NaOH-甲醇溶液2 mL,70℃水浴10 min;10%(V/V)H2SO4-甲醇溶液2 mL,70℃水浴15 min。此条件下的色谱峰的数量多达29种,色谱峰高明显高于其他处理条件下的峰高。     

雌激素对水生生物的影响及其检测方法研究进展

综述了雌激素对水环境的污染现状及其对水生生物的影响,介绍了目前雌激素的检测方法,详细阐述了气相色谱和液相色谱及其联用技术在雌激素测定方面的最新研究进展,并对雌激素的研究方向进行了展望。     

砂质河床对悬浮物去除行为的试验研究

在用雨洪水回灌地下水前,利用天然河床滤除水中悬浮物,可以防止回灌时含水层的物理堵塞。为了系统研究悬浮物粒径、浓度及渗透流速对河床过滤效果的影响,设计和制作了水淘选装置,将河水表层沉积物按粒径分级后,用河砂作为过滤介质进行过滤,测定过滤介质的渗透性和悬浮物分布的变化。结果表明,中值粒径为12.9、7.3和2.3μm的悬浮物分别在表层(5cm)过滤介质内沉积,使该滤层的渗透性分别降低了91.3%、98.6%和99.7%后,可全部去除悬浮物。对于20μm以下的悬浮物,提高浓度会加快其沉积速率,使得悬浮物去除效果快速提高;而提高渗流速度,增加了悬浮物在过滤介质内迁移深度,不利于悬浮物的去除。     

气相色谱在海洋有机化学研究中的应用

本文简要综述了气相色谱在海洋有机地球化学、环境化学和海洋石油勘探方面的应用,并介绍了近10年来以气相色谱为手段研究海洋化学的部分成果。     

Microbial Biomass and Organic Nutrients in the Deep-Sea Sediments of the Central Indian Ocean Basin

In order to assess the impact of deep-sea mining on the in situ benthic life, we measured the microbial standing stock and concentration of organic nutrients in the deep-sea sediments of the Central Indian Ocean Basin in the Indian pioneer area. Sediments were collected using box core and grab samples during September 1996. The total bacterial numbers ranged from 10 10 -10 11 cells per g -1 dry weight sediment. There was a marginal decrease in the number of bacteria from surface to 30 cm depth, though the subsurface section registered a higher number than did the surface. The highest numbers were encountered at depths of 4-8 cm. The retrievable number of bacteria were two orders less in comparison with the direct total counts of bacteria. An almost homogeneous distribution of bacteria, total organic carbon, living biomass, and lipids throughout the depth of cores indicates active microbial and benthic processes in the deep sea sediments. On the other hand, a uniform distribution of total counts of bacteria, carbohydrates, and total organic carbon in all the cores indicates their stable nature and suggests that they can serve as useful parameters for long-term monitoring of the area after the benthic disturbance. Further studies on temporal variability in this region would not only verify the observed norms of distribution of these variables but would also help to understand restabilization processes after the simulated benthic disturbance.     

海上大直径钢管桩打桩过程中桩周土强度弱化研究

海上大直径钢管桩打桩过程中,桩周土体受到强烈扰动而发生强度弱化,掌握桩周土体强度弱化规律对于准确预测打桩过程、保证工程安全具有重要意义。为研究土体强度弱化规律,开展了环剪试验模拟打桩对桩周土体的扰动,测试土体强度随剪切速率的变化规律,建立了描述土体强度弱化规律的拟合公式,引入到打桩分析软件中。研究结果表明：土体的强度折减程度不仅与土体本身的性质有关还受到土体的埋深和剪切速率的影响,埋深越深土体强度折减程度越低,剪切速率越高土体强度折减越高,在打桩分析中可采用这里推荐的线性折减方法来模拟不同深度处土体强度的折减规律。     

Geoacoustic Inversion via Genetic Algorithm and Its Application to Manganese Sediment Identification

An acoustic inversion method using a wide-band signal and two near field receivers is proposed and applied to multiple layered seabed models including a manganese sediment. The inversion problem can be formulated into a probabilistic model comprised of signals, a forward model, and additive noise. The forward model simulates wide-band signals, such as chirp signals, and is chosen to be the source-waveletconvolution plane wave modeling method. The wavelet matching technique, using weighted least-squares fitting, estimates the sediment sound-speed and thickness on which determination of the possible numerical ranges for a priori uniform distribution is based. The genetic algorithm is applied to a global optimization problem to find a maximum a posteriori solution for determined a priori search space. Here the object function is defined by an L 2 norm of the difference between measured and modeled signals. Not only the marginal pdf but also its statistics are calculated by numerical evaluation of integrals using the samples selected during importance sampling process of the genetic algorithm.     

Phylogenetic diversity and phenotypic characterization of cultivable bacterioplankton isolated from polar oceans

A set of 27 marine planktonic bacteria isolated from the polar regions was characterized by 16S rDNA sequencing and physiological and biochemical testing. More than half of these bacteria were positive for caseinase, gelatinase and 13-glucosidase, and could utilize glucose, maltose or malic acid as carbon source for cell growth. Twelve isolates expressed nitrate reduction activities. Except for one antarctic isolate BSwlO175 belonging to Actinobacteria phylum, these isolates were classified as γ-Proteobacteria, suggesting that γ-Proteobacteria dominated in cultivable marine bacterioplankton at both poles. Genus Pseudoalteromonas was the predominant group in the Chukchi Sea and the Bering Sea, and genus ShewaneUa dominated in cultivable bacterioplankton in the Prydz Bay. With sequence similarities above 97%, genus Psychrobacter was found at both poles. These 27 isolates were psychrotolerant, and significant 16S rDNA sequence similarities were found not only between arctic and antarctic marine bacteria （ 〉 99% ）, but also between polar marine bacteria and bacteria from other aquatic environments （ ≥ 98.8% ）, including temperate ocean, deep sea, pond and lake, suggesting that in the polar oceans less temperature-sensitive bacteria may be cosmopolitan and have a bipolar, even global, distribution at the species level.     

Deep-Sea Sediment Compression Curves: Some Controlling Factors, Spurious Overconsolidation, Predictions, and Geophysical Reproduction

Oedometer tests have been carried out on 70 undisturbed surficial clays (at approximately 250 mm below the mudline), mostly collected by free-fall corers from sites widely scattered throughout the deep-sea North Atlantic. Acoustic measurements were also made, initially on contiguous samples and ultimately on the same sample using a geophysically instrumented oedometer which also collected electrical resistivity data. Apart from those quiescent areas below the carbonate compensation depth, such as north of the West Indies where very fine clays exist, most of the samples are silty clays whose geotechnical-geophysical properties are dependent on the type of clay minerals present (and their ability to take in moisture), the sand-size fraction, and the quantity of carbonate present. Thus the pure clays have high compressibilities which decrease on the addition of coarse particles, while the converse is true for the acoustic parameters, these increasing with the sand fraction. Using the notion of the intrinsic compression line for all samples, and comparison to it of the measured compression curves, it is clear that, contrary to some previously held ideas, most deep-sea clays are normally consolidated; the addition of carbonate has the effect of creating an open, stronger sediment skeleton. Interestingly, where information is available, the variation with depth of a sample's acoustic velocity follows the void ratio pressure relationship of the compression curve. This allows the construction of an in-situ sediment compression curve using the in-situ geophysical observations.     

INFORMATION FOR AUTHORS

<正>Acta Oceanologica Sinica(AOS)is a comprehensive academic journal edited by the Editorial Committee of Acta Oceanologica Sinica and is designed to provide a forum for important research papers of the marine scientific community which reflect the information on a worldwide basis.The journal publishes scholarly papers on marine science and technology,including physics,chemistry,biology,     

Estimation of Sediment Properties during Benthic Impact Experiments

Sediment properties, such as water content and density, have been used to estimate the dry and wet weights, as well as the volume of sediment recovered and discharged, during benthic impact experiments conducted in the Pacific and Indian Oceans. The estimates show that the weights of dry (355-1332 t) and wet sediment (1651-4888 t) recovered during the experiments, are not only a function of the total duration and distance covered during the experiment, but also depend on water content and density of the sediment. Estimation of dry sediment and its volumetric ratio in the discharge, are key parameters for calculating the discharged volume. The estimated volume of wet sediment recovered (1427-4049 m 3 ) as well as discharged (2693-6951 m 3 ) during the experiments, provide important inputs to evaluate the sediment resettlement and migration. Using these estimates, the average depth of excavation on the seafloor, can also been calculated. However, the stages of sediment recovery and discharge are expressed differently in some of the experiments. In order to standardize these, different stages have been identified, and definitions of certain terms have been suggested, for use in the future. The methods of calculating different properties, as well as weight and volume of discharged sediment are described in the paper for use in other applications concerning deep-sea discharges.