The authors thank Drs. Bobby J. Presley, Robert Tayloy, Paul Boothe, Mr. Bryan Brattin, and Mr. Mike Metcalf for their assistance during the laborious field sampling and lab work for the practical development and application of "clean techniques".

1.取样准备<ol><li>取样<ol><li>采样器组合<ol><li> 4米长的氟化乙烯丙烯（FEP）管（ID0.635厘米，外径0.95厘米或类似的）连接到1.5米耐化学性的硅树脂泵浦管（外径0.635厘米）。 </li><li>插入聚丙烯Y连接到泵送管和50厘米泵送管连接到一个出口，和一个0.45μm的胶囊型过滤器（由一20厘米泵送管）到另一个。 </li><li>组装在一个干净的房间（工作台）的管路它们清洗后（见下文），并在组装存储在聚乙烯袋两层。 </li></ol></li><li>取样器清洗<ol><li>填充（由1.5米泵送管附着到蠕动泵）的管组与实验室洗涤剂溶液并浸泡24小时。冲洗管道用去离子水集，然后用10％（V / V）盐酸（试剂级）填写并浸泡48小时。 </li><li>彻底冲洗管道，用去离子W设置亚特几次，并储存在塑料袋组合。通过将它们浸泡在50％（体积/体积）HNO 3（试剂级）溶液24小时清洁的Y连接器和短抽管。 </li></ol></li><li>胶囊过滤器<ol><li>通过首先用去离子水冲洗他们48小时浸泡步骤，然后用10％（体积/体积）HCl溶液清洗胶囊型过滤器。 </li><li>酸浸泡后，冲洗用去离子水的过滤器和加入1毫升21％（重量）的NH 4 OH（副煮沸）溶液到每个滤波器以中和酸。 </li><li>密封个别滤波器30厘米清洁泵浦管的环连接在聚乙烯拉链袋的入口和出口，并存储。 </li></ol></li></ol></li><li>样品容器<ol><li>用聚乙烯（PE，1000毫升）和FEP（500毫升和1000毫升）瓶的微量金属容器的决心。 <ol><li>通过首先将它们浸泡在洗涤剂（1％），然后在50％（体积/体积）HNO 3清洗瓶（试剂级）和10％（V / V）盐酸（试剂级）为24，48和24小时的解决方案，分别和冲洗与两个浸泡步骤之间的去离子水的瓶子。 </li><li>最终盐酸浸泡后，彻底用去离子水（DIW）冲洗瓶和干燥在一个干净的房间或类100洁净工作台的瓶（用帽密封）。 </li><li>聚乙烯袋拉链和双包他们聚乙烯袋运输密封清洗瓶。 </li></ol></li><li>干净的玻璃瓶溶解有机碳（DOC）测定<ol><li>浸泡琥珀色硼硅玻璃瓶（40毫升），对溶解有机碳（DOC）的分析，10％盐酸48小时。冲洗用去离子水清洗玻璃瓶，并在480℃下燃烧它们在使用前2小时。单独密封瓶拉链聚乙烯袋运输。 </li></ol></li></ol></li></ol> 2.抽样<ol><li>水样采集<ol><li>牛浦Ñ​​到达在取样点，上外袋标记样品识别号码，并保持瓶在其原始袋。 </li><li>在河岸或在船上，有一个人打开与采样袋和4米FEP管连接到一个3米聚丙烯极（清洗）。延长杆从银行尽可能远并保持FEP管泵被接通之前运行河水的表面下约为30厘米的入口。 </li><li>有另一个人的抽水管连接到蠕动泵（取样泵具有内部电池）的泵头。启动泵和排水（下游侧）的总采样体积的至少3倍。戴上无粉手套，打开瓶子和瓶盖的袋子，开始填充样品瓶。 <ol><li>可替代地，如果另一个人是可用的，具有第三人负责打开内袋和样品盖，并保持该排出样品进b中的采样管的ottle。 </li></ol></li><li>收集在一个125毫升的塑料瓶在场电导率，温度和pH的测量未过滤样品。 </li><li>收集未过滤的样品（500毫升或1,000毫升的微粒样品收集）的第一（通过出口未经过滤器），然后用塑料夹具迫使水去通过囊式过滤器来收集已过滤的水样关闭出口（1 -L溶解微量金属测定）。 </li><li>过滤收集样品（通过与过滤器出口）的40毫升的琥珀色玻璃瓶DOC和EDTA的测量。 </li><li>在近似500ml /分至1000毫升/分的流速收集水样。当压力开始建立（根据过滤器"规范）更换囊式过滤器。对于每种类型的样品，收集额外采样，以及野外空白，在选定的位置，作为质量控制等分。 </li><li>放置在干冰上，并存储我在40毫升的玻璃瓶n中的冰柜，并在冰柜聚乙烯瓶。 </li></ol></li><li>悬浮颗粒物收集（SPM） <ol><li>收集0.4微米聚碳酸酯（PC）膜过滤器的SPM（酸洗涤和预称重）通过真空过滤，用塑料过滤漏斗和容器。 </li><li>冷冻干燥膜过滤器在实验室中产生SPM浓度和微粒的微量金属测定粒子提供样品。 </li></ol></li></ol> 3.样品预处理（溶解的痕量金属） <ol><li>溶解微量金属测定，加入2毫升浓子煮沸HNO 3（每1升样品）到采样瓶。转让溶解微量金属样品（酸化）到FEP瓶。交替，样品可以直接收集到的FEP瓶。紫外线照射在FEP瓶样品24小时（8 15瓦的紫外线灯）。 </li></ol> 4.富集及处理痕量金属分析<ol><l我&gt;树脂富集<ol><li>权衡2克阳离子交换树脂的成小（10-30毫升容量）塑料杯中，并添加2N的HNO 3溶液少量放入杯中。倒入树脂成一个10毫升容量层析柱。通过用5毫升2N的HNO 3洗涤柱清洁树脂（子煮）两次，并用高纯度水（HPW）3次冲洗。 </li><li>加入10 mL 1M的NH 4 OH（分煮）入列到树脂转化为NH 4 +型。 </li></ol></li><li>缓冲溶液（1M乙酸铵） <ol><li>在大约800毫升HPW添加57毫升冰醋酸（亚煮沸）。加〜60毫升氢氧化铵（21％，分煮沸）中，用乙酸混合。调节最终pH至5.5和最终体积至1000毫升</li></ol></li><li>富集过程（溶解微量金属） <ol><li>通过加入30ml的1M ACET铵调节酸化，紫外线照射样品至5.5±0.3的pH值吃缓冲溶液和一些（〜2.8毫升） 的 NH 4 OH（子煮沸）插入采样。 </li><li>将样品瓶〜30厘米挤满了阳离子交换树脂（第4.1节）列上，并用〜60厘米FEP管色谱帽和连接器（母鲁尔）连接样品瓶富集列。 </li><li>控制在3-5毫升/分钟使用2路活塞的流速，列上方连接。允许样品通过该富集列。后，将样品都通过了列，断开列管和帽。 </li><li>用2×5毫升HPW和4×5毫升1M乙酸铵（pH为5.5）和2×5毫升HPW分开来自其它痕量金属主要阳离子的对待的列。 </li><li>放置只是列低于30毫升酸洗涤聚乙烯瓶并用7×1毫升2当量的HNO 3洗涤柱（子煮沸）进入PE瓶中。 </li><li>通过获得重量确定2 N HNO 3流出物（〜8.0毫升）的体积十二次2 N HNO 3流出物的比重。 </li></ol></li><li>悬浮颗粒物消化<ol><li>冷冻干燥过滤器的PC与SPM样品和干燥后秤重。处的SPM的样品，使用过滤器，进入预称重氟烷氧基烷烃（PFA）容器（60毫升容量），并添加3ml浓HNO 3的进入血管。 </li><li>收紧血管2.5公斤米恒定转矩，并在130℃下12小时在常规烘箱消化。冷却后，打开容器，并加2ml HF进入血管。 </li><li>收紧血管2.5公斤米恒定转矩，并在130℃下12小时在常规烘箱消化。冷却后，打开容器并增加16台毫升4.5％硼酸溶液放入容器。 </li><li>收紧血管2.5公斤米恒定转矩，并在130℃下在常规烘箱消化12小时。称重各容器，并确定每个消化溶液的比重产生最终的消化量。 </li><li>计算每个从过滤器的最终体积和重量SPM的消化稀释因子（最终消化体积样品重量上过滤分）。 </li></ol></li></ol> 5.样品分析<ol><li>微量金属<ol><li>测定痕量金属（镉，钴，铜，铁，锰，镍，铅和锌）的浓度在预浓缩溶解的样品和火焰原子吸收光谱法，石墨炉原子吸收光谱微粒的解决方案，和/或电感耦合等离子体质谱仪。 </li><li>由感应耦合等离子体 - 原子发射光谱法确定主要离子浓度和一些痕量金属，以富集之前绘制的子样品和悬浮颗粒物消化，英寸</li></ol></li><li>辅助参数<ol><li>确定样品的温度，pH值，盐度和电导率在外地，使用便携设备。 </li><li>确定溶解或加尼奇碳（DOC）的浓度通过总有机碳分析仪，基于由红外光谱21与二氧化碳检测湿式氧化。确定由高性能液相色谱法（使用的SPD-M10AV Diodearray检测器），按照既定的程序22,23总的EDTA浓度。 </li></ol></li></ol>

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The authors have no conflict of interests to disclose.

在自然水域中获取可靠的微量金属数据需要样品的采集，处理，预处理和分析旨在减少污染期间强调呵护备至。跟踪中获得的天然水域重金属含量中发现，该浓度可以比以前报道的低几个数量级过去二十年来使用"清洁技术"。在水中的微量金属水质标准时，微量金属水平准确测量造成有害影响人类和高等生物更好的评估，现在更容易评估。生物利用度和在水生环境痕量金属的毒性需要在较低浓度?...

人们已经普遍认识到天然水域取得了一些微量金属的结果可能是由于从样本收集，处理和决心1,2过程中应用的技术所产生的不足，文物不准确的。真正的浓度（亚纳米到纳米范围内的地表水3）溶解的微量金属元素是要比以前发表的值低的到现在为止两个数量级。同样的情况在海洋化学凡在大洋水域中溶解的接受微量金属浓度已经超过过去40年减少了数量级左右改进取样和分析方法被引入被发现。已作出努力以改善与"清洁技术"旨在减少或消除微量金属污染的整个痕量金属分析4-8的各个阶段的发展的数据质量。对于重金属含量在环境的决心水平，富集通常需要。离子交换技术的8-12已普遍应用于有效富集。 污染可从容器的壁出现，容器中，取样器，样品处理和存储，以及样品保存和分析7,13的清洗。使用进行了最近的清洁方法，所有的研究表明，在自然水域中重金属含量一般远低于常规方法7检出限。既然承认在90年代初疑微量金属的数据，清洁方法已被纳入美国EPA（环保局）准则痕量金属检测14和美国地质调查局推行清洁方法，为他们的水质监测项目15个 。需要在所有的项目中被采用，以创造一个坚定而准确的数据基础痕量金属研究清洁方法。 <p类="jove_content"&gt;原则上，用于痕量金属测定水样应该用特殊的材料组成，具有仪器分析之前，存储和处理使用适当的容器和设备正确，适当的采样齿轮进行收集。由于悬浮颗粒物（SPM）可以进行在样本储存期的变化和改变水的成分，从水样SPM的快速分离是在水生环境痕量金属研究一种常见的做法。为在自然水域溶解痕量金属浓度的测定，过滤是必需的，并在在线过滤技术是合适的和有效的。 分布和在水生环境中，如地表水和地下水的微量金属的行为可以通过天然（ 例如 ，风化）和人为的影响（ 例如 ，废水流出物）的因素，以及其它环境条件，如重gional地质，形态，土地利用，植被，气候和16-19。然后这会导致诸如悬浮颗粒物浓度（SPM），溶解的有机碳（DOC），人为的配体（ 例如 ，乙二胺四乙酸，EDTA）的盐，氧化还原电位和pH值17-20的物理化学参数的差异。因此，准确和相关的痕量金属研究需要痕量金属分析的样品的适当的收集以及相关因素和参数的确定。

<table><tbody><tr><td>Nitric Acid</td><td>Seastar Chemicals</td><td></td><td>Baseline grade</td></tr><tr><td>Ammonium hydroxide</td><td>Seastar Chemicals</td><td></td><td>Baseline grade</td></tr><tr><td>Acetic Acid</td><td>Seastar Chemicals</td><td></td><td>Baseline grade</td></tr><tr><td>Nitric Acid</td><td>J. T. Baker</td><td>9601-05</td><td>Reagent grade</td></tr><tr><td>Hydrochloric acid</td><td>J. T. Baker</td><td>9530-33</td><td>Reagent grade</td></tr><tr><td>Chromatographic columns</td><td>Bio-Rad</td><td>7311550&amp;nbsp;</td><td>Poly-Prep</td></tr><tr><td>Column stack caps</td><td>Bio-Rad</td><td>7311555</td><td></td></tr><tr><td>Cap connectors (female Luers)</td><td>Bio-Rad</td><td>7318223</td><td></td></tr><tr><td>2-way stopcocks</td><td>Bio-Rad</td><td>7328102</td><td></td></tr><tr><td>Cation exchange resin</td><td>Bio-Rad</td><td>1422832&amp;nbsp;</td><td>Chelex-100</td></tr><tr><td>Portable sampler (sampling pump)</td><td>Cole Palmer</td><td>EW-07571-00</td><td></td></tr><tr><td>FEP tube</td><td>Cole Palmer</td><td>EW-06450-07</td><td>6.4 mm I.D., 9.5 mm O.D.</td></tr><tr><td>Pumping tube</td><td>Cole Palmer</td><td>EW-06424-24</td><td>6.4 mm I.D. C-Flex</td></tr><tr><td>Capsule filter (0.4 mm)</td><td>Fisher Scientific</td><td>WP4HY410F0</td><td>polypropylene casing</td></tr><tr><td>1 L low density polyethylene bottle</td><td>NALGE NUNC INTERNATIONAL</td><td>312088-0032</td><td></td></tr><tr><td>1 L (or 500 ml) FEP bottle</td><td>NALGE NUNC INTERNATIONAL</td><td>381600-0032</td><td></td></tr></tbody></table>

clean sampling and analysis of river and estuarine waters for trace metal studies

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination control. Developments of some techniques aiming to reduce trace metal contamination in the last couple of decades have resulted in concentrations reported now being orders of magnitude lower than those in the past. These low concentrations often necessitate preconcentration of water samples prior to instrumental analysis of samples. Since contamination can appear in all phases of trace metal analyses, including sample collection (and during preparation of sampling containers), storage and handling, pretreatments, and instrumental analysis, specific care needs to be taken in order to reduce contamination levels at all steps. The effort to develop and utilize "clean techniques" in trace metal studies allows scientists to investigate trace metal distributions and chemical and biological behavior in greater details. This advancement also provides the required accuracy and precision of trace metal data allowing for environmental conditions to be related to trace metal concentrations in aquatic environments.
This protocol that is presented here details needed materials for sample preparation, sample collection, sample pretreatment including preconcentration, and instrumental analysis. By reducing contamination throughout all phases mentioned above for trace metal analysis, much lower detection limits and thus accuracy can be achieved. The effectiveness of "clean techniques" is further demonstrated using low field blanks and good recoveries for standard reference material. The data quality that can be obtained thus enables the assessment of trace metal distributions and their relationships to environmental parameters.

随着时代的发展和使用的"清洁技术"，现在清楚地认识到，为了获得在室温水域准确痕量金属浓度，水样品中的微量金属的富集是一种常见的做法。虽然在自然水域中的微量金属大部分的水质标准是在低微克/ L范围内，需要较低的检测限调查在空气中的含量在水生环境的痕量金属地球化学和生物效应。 与以下使用的"清洁技术"?...

Watch this Scientific Journal Video about Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies at JoVE.com

Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

清洁取样和痕量金属研究河和河口水域分析

Most of the trace metal concentrations in ambient waters obtained a few decades ago have been considered unreliable owing to the lack of contamination ...

clean-sampling-analysis-river-estuarine-waters-for-trace-metal

Universidad San Sebastian

Research

JoVE Journal

Environment

11.4K 次观看.  National Sun Yat-sen University. Special care using "clean techniques" is required to properly collect and process water samples for trace metal studies in aquatic environments. A protocol for sampling, processing, and analytical procedures with the aim of obtaining reliable environmental monitoring data and results with high sensitivity for detailed trace metal studies is presented.

视频: Clean Sampling and Analysis of River and Estuarine Waters for Trace Metal Studies

Quantification of Heavy Metals and Other Inorganic Contaminants on the Productivity of Microalgae

Increasing demand for renewable fuels has researchers investigating the feasibility of alternative feedstocks, such as microalgae. Inherent advantages include high potential yield, use of non-arable land and integration with waste streams. The nutrient requirements of a large-scale microalgae production system will require the coupling of cultivation systems with industrial waste resources, such as carbon dioxide from flue gas and nutrients from wastewater. Inorganic contaminants present in these wastes can potentially lead to bioaccumulation in microalgal biomass negatively impact productivity and limiting end use. This study focuses on the experimental evaluation of the impact and the fate of 14 inorganic contaminants (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se, Sn, V and Zn) on Nannochloropsis salina growth. Microalgae were cultivated in photobioreactors illuminated at 984 &#181;mol m-2 sec-1 and maintained at pH 7 in a growth media polluted with inorganic contaminants at levels expected based on the composition found in commercial coal flue gas systems. Contaminants present in the biomass and the medium at the end of a 7 day growth period were analytically quantified through cold vapor atomic absorption spectrometry for Hg and through inductively coupled plasma mass spectrometry for As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sb, Se, Sn, V and Zn. Results show N. salina is a sensitive strain to the multi-metal environment with a statistical decrease in biomass yieldwith the introduction of these contaminants. The techniques presented here are adequate for quantifying algal growth and determining the fate of inorganic contaminants.

Integration of microalgal cultivation with industrial flue gas will ultimately introduce heavy metals and other inorganic compounds into the growth media. This study presents a procedure used to determine the end fate and impact of heavy metals and inorganic contaminants on the growth of Nannochloropsis salina grown in photobioreactors.

重金属和微藻的产其他无机污染物的量化

Increasing demand for renewable fuels has researchers investigating the feasibility of alternative feedstocks, such as microalgae. Inherent advantages ...

科研

环境科学

Sediment Core Sectioning and Extraction of Pore Waters under Anoxic Conditions

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is built and can be transported to a temporary work space close to field sampling site(s) to facilitate rapid analysis. Cores are extruded into a portable glove bag, where they are sectioned and each 1-3 cm thick section (depending on core diameter) is sealed into 50 ml centrifuge tubes. Pore waters are separated with centrifugation outside of the glove bag and then returned to the glove bag for separation from the sediment. These extracted pore water samples can be analyzed immediately. Immediate analyses of redox sensitive species, such as sulfide, iron speciation, and arsenic speciation indicate that oxidation of pore waters is minimal; some samples show approximately 100% of the reduced species, e.g. 100% Fe(II) with no detectable Fe(III). Both sediment and pore water samples can be preserved to maintain chemical species for further analysis upon return to the laboratory.

A protocol for sectioning sediment cores and extracting pore waters under anoxic conditions in order to permit analysis of redox sensitive species in both solids and fluids is presented.

沉积物核心切片和孔隙水萃取缺氧条件下

We demonstrate a method for sectioning sediment cores and extracting pore waters while maintaining oxygen-free conditions. A simple, inexpensive system is ...

Watershed Planning within a Quantitative Scenario Analysis Framework

There is a critical need for tools and methodologies capable of managing aquatic systems within heavily impacted watersheds. Current efforts often fall short as a result of an inability to quantify and predict complex cumulative effects of current and future land use scenarios at relevant spatial scales. The goal of this manuscript is to provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework. Sites are first selected for inclusion within the watershed assessment by identifying sites that fall along independent gradients and combinations of known stressors. Field and laboratory techniques are then used to obtain data on the physical, chemical, and biological effects of multiple land use activities. Multiple linear regression analysis is then used to produce landscape-based cumulative effects models for predicting aquatic conditions. Lastly, methods for incorporating cumulative effects models within a scenario analysis framework for guiding management and regulatory decisions (e.g., permitting and mitigation) within actively developing watersheds are discussed and demonstrated for 2 sub-watersheds within the mountaintop mining region of central Appalachia. The watershed assessment and management approach provided herein enables resource managers to facilitate economic and development activity while protecting aquatic resources and producing opportunity for net ecological benefits through targeted remediation.

There is a critical need for tools and methodologies capable of managing aquatic systems in the face of uncertain future conditions. We provide methods for conducting a targeted watershed assessment that enables resource managers to produce landscape-based cumulative effects models for use within a scenario analysis management framework.

定量的情景分析框架内流域规划

There is a critical need for tools and methodologies capable of managing aquatic systems within heavily impacted watersheds. Current efforts often fall ...

Continuous Instream Monitoring of Nutrients and Sediment in Agricultural Watersheds

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in water resources is a prerequisite for understanding the drivers of the pollutant loads and for making informed water resource management decisions. The commonly used &#34;grab sampling&#34; method provides the concentrations of pollutants at the time of sampling (i.e., a snapshot concentration) and may under- or overpredict the pollutant concentrations and loads. Continuous monitoring of nutrients and sediment has recently received more attention due to advances in computing, sensing technology, and storage devices. This protocol demonstrates the use of sensors, sondes, and instrumentation to continuously monitor in situ nitrate, ammonium, turbidity, pH, conductivity, temperature, and dissolved oxygen (DO) and to calculate the loads from two streams (ditches) in two agricultural watersheds. With the proper calibration, maintenance, and operation of sensors and sondes, good water quality data can be obtained by overcoming challenging conditions such as fouling and debris buildup. The method can also be used in watersheds of various sizes and characterized by agricultural, forested, and/or urban land.

With the advancement of technology and the rise in end-user expectations, the need and use of higher temporal resolution data for pollutant load estimation has increased. This protocol describes a method for continuous in situ water quality monitoring to obtain higher temporal resolution data for informed water resource management decisions.

农业流域营养盐和泥沙的连续河道监测

Pollutant concentrations and loads in watersheds vary considerably with time and space. Accurate and timely information on the magnitude of pollutants in ...

An Ultra-clean Multilayer Apparatus for Collecting Size Fractionated Marine Plankton and Suspended Particles

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those of suspended/sinking particles. Here, we present an all plastic (Polypropylene and Polycarbonate), multi-layer filtration system for collection of suspended particulate matter (SPM) at sea. This ultra-clean sampling device has been designed and developed specifically for trace element studies. Meticulous selection of all non-metallic materials and utilization of an in-line flow-through procedure minimizes any possible metal contamination during sampling. This system has been successfully tested and tweaked for determining trace metals (e.g., Fe, Al, Mn, Cd, Cu, Ni) on particles of varying size in coastal and open ocean waters. Results from the South China Sea at the South East Asia Time-Series (SEATS) station indicate that diurnal variations and spatial distribution of plankton in the euphotic zone can be easily resolved and recognized. Chemical analysis of size-fractionated particles in surface waters of the Taiwan Strait suggests that the larger particles (&#62;153 &#181;m) were mostly biologically derived, while the smaller particles (10 - 63 &#181;m) were mostly composed of inorganic matter. Apart from Cd, the concentrations of metals (Fe, Al, Mn, Cu, Ni) decreased with increasing size.

Plankton and suspended particles play a major role in the biogeochemical cycles in the ocean. Here, we provide an ultra-clean, low stress method for the collection of various sizes of particles and plankton at sea with the capability of handling large volumes of seawater.

海洋浮游生物和悬浮颗粒的超洁净多层采集装置

The distributions of many trace elements in the ocean are strongly associated with the growth, death, and re-mineralization of marine plankton and those ...

Seawater Sampling and Collection

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses. For today's demonstration samples were collected from the deck of the HMS John Strickland operating in Saanich Inlet. An A-frame derrick, with a multi-purpose winch and cable system, is used in combination with Niskin or Go-Flo water sampling bottles. Conductivity, Temperature, and Depth (CTD) sensors are also used to sample the underlying water mass. To minimize outgassing, trace gas samples are collected first.  Then, nutrients, water chemistry, and cell counts are determined. Finally, waters are collected for biomass filtration. The set-up and collection time for a single cast is ~1.5 hours at a maximum depth of 215 meters. Therefore, a total of 6 hours is generally needed to complete the collection series described here.

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass concentration, nucleic acid purification, cell abundance, nutrient and trace gas analyses.

海水采样和收集

This video documents methods for collecting coastal marine water samples and processing them for various downstream applications including biomass ...

生物学

Dissolved Solute Sampling Across an Oxic-Anoxic Soil-Water Interface Using Microdialysis Profilers

Biogeochemical processes shift rapidly in both spatial (millimeter scale) and temporal (hour scale to day scale) dimensions at the oxic-anoxic interface in response to disturbances. Deciphering the rapid biogeochemical changes requires in situ, minimally invasive tools with high spatial and temporal sampling resolution. However, the available passive sampling devices are not very useful in many cases either due to their disposable nature or the complexity and extensive workload for sample preparation.
To address this problem, a microdialysis profiler with 33 individual polyethersulfone nanomembrane tubes (semipermeable, &#60;20 nm pore size) integrated into the one-dimensional skeleton (60 mm) was established to iteratively sample the dissolved compounds in porewater across the soil-water interface at a high resolution of 1.8 mm (outer diameter plus one spacing, i.e., 0.1 mm between probes). The sampling mechanism is based on the principle of concentration gradient diffusion. The automatic loading of degassed water allows minimal disturbance to the chemical species across the oxic-anoxic interface.
This paper describes the procedures of device setup and continuous porewater sampling across the soil-water interface on a daily basis. Concentration-depth profiles were selectively measured before (on Day 6) and after (on Day 7) disturbances induced by irrigation. The results showed that concentration-depth profiles were undergoing rapid changes, especially for redox-sensitive elements (i.e., iron and arsenic). These protocols can help investigate the biogeochemical responses across the soil-water interface under various disturbances caused by physical, chemical, and biological factors. The paper thoroughly discusses the advantages and disadvantages of this method for potential use in the environmental sciences.

A microdialysis profiler is described to sample dissolved porewater solutes across an oxic-anoxic soil-water interface in situ with minimal disturbance. This device is designed to capture rapid changes in concentration-depth profiles induced by disturbances at the soil-water interface and beyond.

使用微透析剖面仪在氧化-缺氧土壤-水界面上进行溶解溶质采样

Biogeochemical processes shift rapidly in both spatial (millimeter scale) and temporal (hour scale to day scale) dimensions at the oxic-anoxic interface ...

Hellgrammite as a Non-Conventional Biomonitor for Surface Water and Environmental Health Assessment

The larvae of dobsonflies from the genus Corydalus, commonly known as Hellgrammites, are characterized by their notable size, extensive range of occurrence, and extended period of immaturity, which can last up to one year. Hellgrammites are clearly known to exhibit sensitivity to pollution and habitat structure impacts. Given these unique features, using Corydalus texanus larvae is highly suitable as reliable biomonitoring agents to assess the ecological integrity of aquatic ecosystems. This protocol aims to provide the necessary tools for C. texanus assessment and demonstrate their efficacy through a case study. Research findings have practical implications, indicating that C. texanus larvae exhibit early-warning responses to mining pollution, bioaccumulating high amounts of heavy metals such as Zn, Fe, and Al. The presence or absence of C. texanus populations may serve as a helpful indicator for identifying potential issues related to ecosystem health. The unconventional approach has shown early warnings of pollution in mining-impacted sites, highlighting the need for timely action to protect the environment. Given their unique traits, the use of C. texanus larvae is highly suggested as a reliable non-conventional bioindicator.

This protocol describes the use of biomarkers for the early detection of deleterious impacts in aquatic ecosystems. The biomarkers are closely related to sentinel traits, and their changes aid in detecting early-warning damages.

Hellgrammite 作为地表水和环境健康评估的非常规生物监测器

The larvae of dobsonflies from the genus Corydalus, commonly known as Hellgrammites, are characterized by their notable size, extensive range of ...

Fabrication of a Dipole-assisted Solid Phase Extraction Microchip for Trace Metal Analysis in Water Samples

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water samples. A brief overview of the evolution of chip-based SPE techniques is provided. This is followed by an introduction to specific polymeric materials and their role in SPE. To develop an innovative dipole-assisted SPE technique, a chlorine (Cl)-containing SPE functionality was implanted into a poly(methyl methacrylate) (PMMA) microchip. Herein, diverse analytical techniques including contact angle analysis, Raman spectroscopic analysis, and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis were employed to validate the utility of the implantation protocol of the C-Cl moieties on the PMMA. The analytical results of the X-ray absorption near-edge structure (XANES) analysis also demonstrated the feasibility of the Cl-containing PMMA used as an extraction medium by virtue of the dipole-ion interactions between the highly electronegative C-Cl moieties and the positively charged metal ions.

The fabrication protocol of a dipole-assisted solid phase extraction microchip for the trace metal analysis is presented.

水样中偶极辅助固相萃取Microchip的痕量金属分析的制作

This paper describes a fabrication protocol for a dipole-assisted solid phase extraction (SPE) microchip available for trace metal analysis in water ...

生物工程

Quantification of Metal Leaching in Immobilized Metal Affinity Chromatography

Contamination of enzymes with metals leached from immobilized metal affinity chromatography (IMAC) columns poses a major concern for enzymologists, as many of the common di-and trivalent cations used in IMAC resins have an inhibitory effect on enzymes. However, the extent of metal leaching and the impact of various eluting and reducing reagents are poorly understood in large part due to the absence of simple and practical transition metal quantification protocols that use equipment typically available in biochemistry labs. To address this problem, we have developed a protocol to quickly quantify the amount of metal contamination in samples prepared using IMAC as a purification step. The method uses hydroxynaphthol blue (HNB) as a colorimetric indicator for metal cation content in a sample solution and UV-Vis spectroscopy as a means to quantify the amount of metal present, into the nanomolar range, based on the change in the HNB spectrum at 647 nm. While metal content in a solution has historically been determined using atomic absorption spectroscopy or inductively coupled plasma techniques, these methods require specialized equipment and training outside the scope of a typical biochemistry laboratory. The method proposed here provides a simple and fast way for biochemists to determine the metal content of samples using existing equipment and knowledge without sacrificing accuracy.

We present an assay for easy quantification of metals introduced to samples prepared using immobilized metal affinity chromatography. The method uses hydroxynaphthol blue as the colorimetric metal indicator and a UV-Vis spectrophotometer as the detector.

金属浸出在固定金属亲和力色谱中的定量

Contamination of enzymes with metals leached from immobilized metal affinity chromatography (IMAC) columns poses a major concern for enzymologists, as ...