海藻中EPA,DHA萃取技术的比较研究

在优化条件下比较了溶剂法（SE）、超声强化溶剂法（USE）、超临界CO2法（SFE）及超声强化超临界CO2法（USFE）从海藻中提取EPA和DHA。研究表明，超声对溶剂提取和超临界流体萃取过科都具有强化作用。超声强化溶剂提取过程，使提取时间缩短1h，提取温度低10℃，EPA，DHA提取率分别提高16．61％，16．41％，而且溶剂用量少。超声强化超临界萃取过程，萃取系统的压力降低了5MPa、萃取温度和萃取时间分别由45℃，210min降至35℃，180min，EPA和DHA萃取率分别提高15．09％和15．96％。UV与GC-MS分析结果表明，实验条件下，超声场的加入没有改变EPA，DHA的结构。     

超声波提取-固相萃取联用检测河鲀毒素的研究

使用热处理、震摇、超声波等手段改善水产品中的河鲀毒素提取率,利用多种固相萃取柱纯化提取液,采用高效液相色谱-紫外检测法进行检测,重点对河鲀毒素的提取和固相萃取纯化进行了研究。试验发现,结合振荡和加热双重作用的索氏提取法和超声波加热辅助提取法具有较高的提取能力,其中超声波(35kHz,强度100%,60℃)提取10min即可达到最好效果,耗时短,效率更高;比较SCX、PRS、WCX、C18、SAX 5种固相萃取柱对河鲀毒素的吸附作用,SCX、PRS、WCX柱则能够将河鲀毒素完全保留在其上。样品纯化试验结果显示,C18-WCX小柱的组合纯化样品的效果最好,回收率在75%—82%之间,相对标准偏差小于15%。研究结果对河鲀毒素的提取、纯化和检测工作具有重要的参考意义。     

现场自动过滤萃取采样技术

本文介绍国内、外现场自动过滤萃取采样技术的现状和发展水平、研究内容、研究方法以及目前所进行的研究工作,并对以后的发展趋势进行了预测。     

pH对SPE-HPLC-ESI-Q-TOF-MS检测海水中小分子活性物质的影响研究

海水溶解有机物(dissolvedorganicmatter,DOM)中含有的生物活性物质在海洋生态系统中作用巨大,但因缺乏适合的分离提取方法而严重阻碍了对其不同组分在生态系统中作用的探索。固相萃取法对富集提取海水DOM十分有效,在用其提取海水DOM时,海水pH对活性物质提取效果的影响很大,但目前针对海水的这种影响尚存在很大争议。本文以天然近海海水作为基质,探究不同pH条件下用亲水-疏水平衡(hydrophilic-lipophilicbalanced,HLB)固相萃取小柱萃取海水中活性分子的提取效率,并使用高效液相色谱-四极杆飞行时间质谱(HPLC-Q-TOF-MS)在负离子(ESI-)模式下检测解析提取物的组成。研究结果表明,当海水样品pH为中性和强酸性时都能获得较好的提取效率,随着pH的降低,提取物质谱的整体响应值降低,但可识别的谱峰数目增加,提取出有机物的分子量和性质差异都更广泛。分析提取物分子在范克雷维伦(van Krevelen)图和质荷比-氢碳比(m/z-H/C)图上的分布发现,中性条件适合提取饱和度较高的小分子化合物,而具有生物活性的带有不饱和基团的化合物及蛋白质、糖类等生物大分子在强酸性提取条件时提取效果和分辨率更好。综合提取效率、有效峰数目和分子组成特征考虑,用HLB固相萃取小柱提取近海海水中的小分子活性物质时,将海水样品pH调节为2较为适宜。     

基于遥感数据的水边线提取方法比较——以海南岛为例

海岸带是人类活动的重要区域,遥感技术因其优势被广泛应用于海岸带研究,而如何高效地从遥感影像中提取出高精度岸线是海岸带研究的重要问题。本文总结了国内外9种主要水边线提取方法的特点,采用目视解译、阈值分割法（NDWI、MNDWI和SMNDWI）、边缘检测算子法（Sobel、Roberts和Canny）3种最常用的方法提取了...     

超声萃取气相色谱法检测海洋沉积物中的总石油烃

简便快速准确的沉积物中石油烃检测方法的建立对于评估海洋环境中石油的污染程度,以及对应防治措施的选取意义重大.本文探讨了索氏提取、振荡提取和超声萃取法对沉积物中总石油烃的提取效率,并用正交实验优化提取条件.得到的最优方法为:59沉积物加15 mL二氯甲烷超声萃取4次,每次15min,硅胶和氧化铝净化提取液,GC-FID检测.用此方法提取加油量为lmg/g沉积物,回收率均值达99.4％,标准偏差为1.9％,重复性好.     

基于高效液相色谱法的扇贝毒素-2制备方法研究

本文以渐尖鳍藻(Dinophysis acuminata)为实验原料,建立了基于高效液相色谱法(HPLC)的扇贝毒素-2(Pectenotoxin-2,PTX2)的制备方法。研究重点对鳍藻细胞的破碎、PTX2毒素的提取及HPLC纯化等三个步骤的方法进行筛选和优化。结果表明,反复冻融与超声波细胞破碎相结合可获得最大的细胞破碎率和毒素提取率,分别为99.2%和81.5%。采用四种有机试剂(甲醇、丙酮、乙醚、二氯甲烷)及三种固相萃取小柱(Solid Phase Extraction,SPE)(Oasis HLB SPE,Phenomenex Strata-X SPE,Sep-Pak C18 SPE)对PTX2毒素进行提取,其中乙醚-二氯甲烷的提取效率最高,达78.2%。在HPLC对PTX2毒素的纯化实验中发现,流动相的pH会影响毒素组分的分离,其中在碱性流动相(含6.7mmol/L氨水的水溶液和乙腈溶液,pH=10.94)条件下,PTX2的分离效果最佳,响应值最高。实验使用Phenomenex Kinetex C18(4.8mm×250mm,5μm)色谱柱,在上述碱性流动相条件下,分离得到纯度为93.2%的PTX2毒素。本研究选定的藻细胞破碎、PTX2毒素提取、及HPLC纯化方法简单快捷,高效易操作,为从大规模培养的鳍藻细胞中制备高纯度PTX2毒素提供了技术支持。     

马粪海胆生殖腺粗多糖提取工艺研究

采用L9(3~4)正交实验,以马粪海胆(Hemicentrotus pulcherrimus)生殖腺粗多糖得率为指标,研究提取温度、提取时间、料水比、提取次数4个因素对马粪海胆生殖腺粗多糖提取工艺的影响。以正交实验的实验条件和马粪海胆生殖腺粗多糖得率为自变量和因变量建立多元线性模型,所得到的统计参数分别为R=0.922,F=2.854,并用所建立的线性模型预测两个实验条件的多糖得率。     

牛津杯法测定五倍子对大黄鱼病原弧菌的体外抑菌活力

实验采用乙醇蒸馏法、超声提取法两种不同提取工艺分别制备五倍子药液,并选用牛津杯法研究了两种提取药液对大黄鱼(Pseudosciaena crocea)几种病原弧菌的体外抑菌效果差异.结果显示,两种五倍子药液对病原弧菌均具有明显的抑制效果,而超声所提药液的抑菌效果明显强于乙醇蒸馏法所提药液.     

硅藻粘附性EPS提取方法的比较研究

底栖硅藻是可见光能照射到的水下表面生物膜中的主要污损生物,胞外多聚物(Extracellular Polymeric Substances,EPS)是硅藻生物膜形成和发育过程中的关键物质,可溶性EPS和粘附性EPS的提取方法不同,对粘附性EPS的分离提取仍没有统一的方法。本研究选用了4种方法提取底栖硅藻(Amphora sp.)粘附性EPS:30℃水浴处理、70℃水浴处理、福尔马林-NaOH处理和阳离子交换树脂处理,研究了不同分离方法条件下,Amphora sp.粘附性EPS中各主要成分的提取量。结果表明,粘附性EPS中各主要成分普遍受提取方法的影响,其中DNA含量变化幅度最大,其次是蛋白质、总糖和糖醛酸含量,硫酸基含量受提取方法的影响最小。低温水浴处理提取效率低,高温水浴处理可能影响EPS的后续分析,阳离子交换树脂提取粘附性EPS的效果较好,但对细胞的破坏最严重,福尔马林-NaOH处理提取的EPS总量最高,提取总糖、糖醛酸的效果最好,而且没有造成严重的细胞破裂。因此福尔马林-Na OH处理是相对均衡和高效的提取硅藻粘附性EPS的方法。     

Size-fractionated uranium isotopes in surface waters in the Jiulong Estuary in China

Surface water was collected from the Jiulong Estuary for determination of activity concentrations of uranium isotopes in different size fractions, namely, greater than 53, 10 -53, 2 - 10, 0.4 -2 μm, 10 000 u -0.4 μm and less than 10 000 u fractions by microfihration and cross-flow uhrafiltration technologies. Results indicated that most of the dissolved uranium （ 〈 0.4 μm） exis- ted in the low molecular mass fraction （ 〈 10 000 u）, and the colloidal uranium-238 （10 000 u -0.4 μm） only contributed less than 1% of the dissolved uranium-238. The fractions of colloidal uranium in the dissolved phases decreased with the increasing sa- linity. A positive linear relationship between uranium-238 activities and salinities was observed for the dissolved, colloidal and low molecular mass fractions, indicating a conservative behavior of uranium in the Jiulong Estuary. In the particulate phases （ 〉 0.4 μm）, the partitioning of uranium isotopes among different size fractions was controlled by the partitioning of particle concentrations. In the regions with salinities below 20, the partitioning of uranium-238 among different size fractions was as follows： 10 - 53 μm 〉 2 - 10 μm 〉 0.4 - 2 μm greater than above 53 μm. However, the order at the offshore station with salinities above 30 changed as follows ： 0.4 - 2 μm 〉 10 - 53 μm 〉 2 - 10 μm greater than above 53 μm. The fraction of the 0.4 - 2 μm particles increased at the offshore station, suggesting the increased contribution of the authigenic uranium. The activity ratio of uranium-234 to uranium-238 in the dissolved phases, including the low molecular mass fraction and the colloidal fraction, was larger than unity, showing the occurrence of excess uranium-234. In contrast, the activity ratio of uranium-234 to uranium-238 in all size fractions of the particulate phase was close to the equilibrium value （1.0）. The observed different values of the activity ratio of uranium-234 to uranium-238 in the dissolved phase and the partic     

Recent advances in marine technology in Canada

Much of the recent Canadian activity in marine technology has focused on development of capabilities in Arctic waters, and on the update and replacement of naval vessels. This paper describes some of the significant projects and programs now under way, and suggests future research and development requirements.     

一氧化氮在浮游植物中的研究进展

对一氧化氮在浮游植物中的研究进展进行了归纳,总结了一氧化氮对浮游植物生长的影响,探讨了浮游植物中一氧化氮的产生机制,并对今后的研究重点提出展望。     

Challenges in cross-sectoral marine protection in Europe

Marine environment protection in Europe faces a number of challenges. One is the coordination of relevant sectoral policies — such as agricultural and fisheries policies — with regard to marine protection objectives. The question in the following is on how marine protection issues can be more closely integrated in sectoral policies under the conditions prevailing at present. In particular the strength and weaknesses of the Marine Strategy Framework Directive (MSFD) as the key instrument for marine environment protection in Europe are analyzed in this context. In particular, the MSFD does not adequately address all sectors and policies which are relevant to marine environment protection. One possible means of giving the MSFD greater influences on other policies of relevance to marine waters is to integrate the objectives established under the MSFD in the European maritime policy. The aim should be to require the further development of sectoral policies to take unrestricted account of the objectives of the MSFD implementation process. But also other instruments of marine policy such as maritime spatial planning and marine protected areas are crucial to advance the protection of European seas.     

夏季珠江口沉积物中营养盐剖面分布和界面交换通量

通过对夏季珠江口区域沉积物间隙水营养盐剖面分析,调查了营养盐含量分布和特征,探讨了有机物的降解特性、营养盐的底部通量估算和作用.结果表明,珠江口沉积物间隙水中营养盐以高含量铵盐为主要的存在形式,沉积物中有机物的降解反应主要在厌氧状态下进行,底部水体铵盐的增加来源于底部沉积物有机质的降解释放,而且对水体的营养盐循环有较大的贡献.     

Recent progress in submarine geosciences in China

In China submarine geosciences represents a newly established discipline of oceanography, focusing on the oceanic lithosphere, and its interface with the hydrosphere and biosphere. Recently, supported by the National High Technology Research and Development Program and other high-tech development projects, significant progress has been made in the development of advanced technologies and equipment. This en- ables the scientists in China to carry out explorations of the international seabed area in the Pacific Ocean and on the Southwest Indian Ridge. In addition, they have been active in the research activities associated the mid-ocean ridges and western Pacific marginal seas. It is anticipated that this research field will continue to be highly fruitful in the near future.     

湄洲湾夏季的初级生产力

湄洲湾１９９２年夏季的叶绿素ａ，三磷酸腺苷，碳比积累速率，初级生产力的变化范围和均值分别为０．４５－４．７２，１．４９ｍｇ／ｍ＾３；０．１２－１．０７，０．３１μｇ／ｄｍ＾３；０．０６－０．５８，０．３４ｄ＾－１；０．０７－０．３４，０．２１ｍ／（ｍ＾２．ｄ）。叶绿素ａ与三磷酸腺苷之间。初级生产力与碳比积累速率之间均呈正相关关系。叶绿素ａ三磷本能腺苷的比值为４．８，湄洲湾夏季浮游植物的生长受氮不足     

Seasonality in nutrient concentrations in Galveston Bay

In order to investigate factors controlling nutrient cycling in the shallow and turbid coastal ecosystem of Galveston Bay, data from: (1) the Texas Water Commission (TWC) database 1980–1989, and (2) salinity transects in 1989 and 1993 are presented and analyzed. Statistical regression and time-series analysis were carried out on data acquired by TWC between 1980 and 1989, in an attempt to establish seasonally of nutrient and chlorophyll-a (chl.-a.) concentrations in the bay and to determine factors which regulate these concentrations.A strong seasonality was found for phosphorus and chl.-a. in the upper and mid-bay stations. A recurring maximum for phosphate occurred in September and a chl.-a. maximum occurred regularly in March–April. It is hypothesized that benthic regeneration of phosphorus at the end of summer is responsible for the phosphate maximum. The inverse correlation of the partition coefficient (K_d) for phosphate with the concentration of suspended particulate matter (SPM), coupled to a strong enrichment of phosphate in suspended particles at low SPM concentrations, indicates additional control by geochemical and physical processes such as particle sorting and/or particle-colloid interactions. Nitrate is inversely correlated with salinity at the upper and mid-bay stations, indicating the Trinity River is a major source.Nutrient concentrations in the lower bay (East and West Bay stations) are considerably lower and less predictable, as they are not correlated with salinity or temperature. Data from the 1989 and 1993 transects confirm the yearly maximum in phosphate concentration in late summer months, with peak concentrations in the upper Trinity Bay. It is concluded that despite possible phosphate buffering by physical and geochemical mechanisms, relatively large concentration maxima recur regularly every year during the summer, possibly caused by a benthic source of phosphate.