Name: a simple method for automated solid phase extraction of water samples for immunological analysis of small pollutants
Uploaded: 2016-01-01T14:00:00
Description: Watch this Scientific Journal Video about A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants at JoVE.com

This work was funded by the European Union Seventh Framework Program FP7/2007-2013 under grant agreement no. 265721. The authors thank the RIKILT Institute for Food Safety (NL) for their support in this project.

Note: The following protocol describes the SPE performed on 100 ml water sample with C18 sorbent and elution with 50% v/v methanol. The enriched sample is diluted to reach 10% v/v methanol before analysis with an enzyme linked immunosorbent assay (ELISA) kit.
1. Preparing the Reagents
<ol>
	<li>Prepare the water samples
	<ol>
		<li>Prior to any other step, filter each 100 ml water sample with 0.2 &#181;m pore size filters.</li>
		<li>Spike the sample with desired concentration by diluting ap...

<ol>
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J., Barcelo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparative+study+of+an+estradiol+enzyme-linked+immunosorbent+assay+kit,+liquid+chromatography-tandem+mass+spectrometry,+and+ultra-performance+liquid+chromatography-quadrupole+time+of+flight+mass+spectrometry+for+part-per-trillion+analysis+of+estrogens+in+water+samples.">Comparative study of an estradiol enzyme-linked immunosorbent assay kit, liquid chromatography-tandem mass spectrometry, and ultra-performance liquid chromatography-quadrupole time of flight mass spectrometry for part-per-trillion analysis of estrogens in water samples.</a> J. Chromatogr. A. 1160, 166-175 (2007).</li><li>Pu, C., Wu, Y. F., Yang, H., Deng, A. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Trace+analysis+of+contraceptive+drug+levonorgestrel+in+waste+water+samples+by+a+newly+developed+indirect+competitive+enzyme-linked+immunosorbent+assay+(ELISA)+coupled+with+solid+phase+extraction.">Trace analysis of contraceptive drug levonorgestrel in waste water samples by a newly developed indirect competitive enzyme-linked immunosorbent assay (ELISA) coupled with solid phase extraction.</a> Anal. Chim. Acta. 628, 73-79 (2008).</li><li>Van Emon, J. M., Gerlach, C. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+status+report+on+field-portable+immunoassay.">A status report on field-portable immunoassay.</a> Environ. Sci. Technol. 29 (7), 312A-317A (1995).</li><li>Farr&#233;, M., Brix, R., Barcel&#242;, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Screening+water+for+pollutants+using+biological+techniques+under+European+Union+funding+during+the+last+10+years.">Screening water for pollutants using biological techniques under European Union funding during the last 10 years.</a> Trends Anal. Chem. 24 (6), 532-545 (2005).</li><li>Schneider, C., Sch&#246;ler, H. F., Schneider, R. 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J., Barcelo, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Endocrine+disrupting+compounds+and+other+merging+contaminants+in+the+environment:+a+new+survey+on+new+monitoring+strategies+and+occurrence+data.">Endocrine disrupting compounds and other merging contaminants in the environment: a new survey on new monitoring strategies and occurrence data.</a> Anal. Bioanal. Chem. 378, 549-562 (2004).</li><li>Richardson, S. D., Ternes, T. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Water+analysis:+Emerging+contaminants+and+current+issues.">Water analysis: Emerging contaminants and current issues.</a> Anal. Chem. 86, 2813-2848 (2014).</li></ol>

A new method for the preparation of water samples followed by analysis using immunoassay was proposed. The instrument enables to perform solid phase extraction in an automated and user-friendly way.
The filtration of the water sample prior to its injection into the system is critical. Any particulates still present in the solution would potentially cause clogging of the fluidic network and obstruct the SPE column. Another important step is the preparation of the SPE column. The amount of parti...

Sample preparation is an important step in any analytical process. In particular, removal of matrix effects, diminution of interferences, and enrichment of the analyte are necessary to obtain precise results and reach low limits of detection. Endocrine disrupting compounds (EDCs) are of particular concern due to their action on the living organisms even when present at very low levels in the environment. The natural hormone 17&#946;-estradiol is present on the EU water pollution Watch List and prone to be added to the list of priority substances regulated under the European Water Framework Directive. Solid phase extraction (SPE) is commonly applied for the analysis of small pollutants in water, with both chemical 1-5 (chromatography, mass spectrometry) and immunological 6-9 detection methods. The latter gained interest in the field of environmental monitoring, as immunoassays are available in large variety of formats, are specific to the target analyte, and reach low limits of detection.6, 7, 10, 11 Various enzyme linked immunosorbent assays (ELISA) are commercially available and enable to analyze multiple samples at once on a multi-well plate. The procedure consists in successive reaction steps that can take a few hours. The final product of reaction can be detected optically to determine the concentration of the target molecule based on a calibration curve.
Classical SPE procedures include sorbent pre-conditioning, sample extraction, washing, elution, and concentration by evaporation of the eluent. The solvent used for dilution of this extract is chosen depending on the detection method. For immunological methods, the amount of organic solvent influences strongly the sensitivity of the method.12
In addition to the recovery and the pre-concentration performances, the method also needs to be simple and cost efficient. Automation of the procedure helps to reduce human-related errors. In our previous work 13 we introduced our prototype for automated SPE, and our method was applied to the analysis of the natural hormone 17&#946;-estradiol in sea water samples. With the present video we would like to highlight the technical advantages of our method compared to traditional off-line and on-line SPE, and its particular compatibility with detection by immuno-reactions. We describe the protocol applied to water samples for the detection of 17&#946;-estradiol. SPE is performed with octadecyl-silica (C18) sorbent phase and elution is performed with diluted methanol.

<table border="0" cellpadding="0" cellspacing="0" width="609">
	<tbody>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Filter membrane 0.2 &#956;m pore size</td>
			<td style="width:107px;">Merck Millipore</td>
			<td style="width:119px;">GNWP04700</td>
			<td style="width:167px;">For sample filtration</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Nylon membrane 11 &#956;m pore size</td>
			<td style="width:107px;">Merck Millipore</td>
			<td style="width:119px;">NY1104700</td>
			<td>For SPE column</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Disposable biopsy punch 5 mm</td>
			<td style="width:107px;">Medical Budget</td>
			<td style="width:119px;">39302439</td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">Nucleodur C18 ec&#160;</td>
			<td style="width:107px;">Macherey Nagel</td>
			<td style="width:119px;">713550.01</td>
			<td>50 &#956;m particle diameter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Synthetic sea water</td>
			<td style="width:107px;">Sigma Aldrich</td>
			<td style="width:119px;">SSWS500-500ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Methanol</td>
			<td style="width:107px;">VWR</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">17beta-estradiol standard</td>
			<td style="width:107px;">Enzo Life Science</td>
			<td style="width:119px;"></td>
			<td>300 ng/ml</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:216px;">17beta-estradiol ELISA kit&#160;</td>
			<td style="width:107px;">Enzo Life Science</td>
			<td style="width:119px;">ADI-900-008</td>
			<td>96 wells, range 30 - 3000 ng/L</td>
		</tr>
	</tbody>
</table>

a simple method for automated solid phase extraction of water samples for immunological analysis of small pollutants

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and enables to perform rapid, automated and simple SPE. The pre-concentrated solution is compatible with analysis by immunoassay, with a low organic solvent content. A method is described for the extraction and pre-concentration of natural hormone 17&#946;-estradiol in 100 ml water samples. Reverse phase SPE is performed with octadecyl-silica sorbent and elution is done with 200 &#181;l of methanol 50% v/v. Eluent is diluted by adding di-water to lower the amount of methanol. After preparing manually the SPE column, the overall procedure is performed automatically within 1 hr. At the end of the process, estradiol concentration is measured by using a commercial enzyme-linked immune-sorbent assay (ELISA). 100-fold pre-concentration is achieved and the methanol content in only 10% v/v. Full recoveries of the molecule are achieved with 1 ng/L spiked de-ionized and synthetic sea water samples.

Reproducibility of sorbent packing was evaluated by drying and weighting the pipetted sorbent in glass vials and the result is shown in Figure 1. Reproducibility of the time of injection was tested for 100 ml samples, as shown in Figure 2. Concentration in initial and pre-concentrated spiked samples were determined by using a commercial ELISA kit for 17&#946;-estradiol and are shown in Figure 3.
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Watch this Scientific Journal Video about A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants at JoVE.com

A Simple Method for Automated Solid Phase Extraction of Water Samples for Immunological Analysis of Small Pollutants

A protocol for the extraction and pre-concentration of estradiol from water samples by using an automated and miniaturized system is presented.

A new method for solid phase extraction (SPE) of environmental water samples is proposed. The developed prototype is cost-efficient and user friendly, and ...

The overall goal for this sample preparation method is to pre-concentrate small, organic pollutants from water samples, in a user friendly, cost effective and automated way. This method can replace standard SPE processes when studying the contamination of water samples using immunodetection methods, such as well plate immunoassays or biosensors. The main advantages of this technique is that SPE procedure is automated while the footprint and cost of the instruments are low compared to traditional approaches.In addition, the performances of the enrichment process match the requirement of analysis of immunoassays both in terms of low solvent content and pre-concentration efficiency. First, filter out 100 millimeter water sample with a zero point two micrometer pour size filter. Place the filtered sample in a glass bottle with GL 45 thread.Prepare 300 microliters of eluent by diluting methanol in deionized water, to 50 percent volume in a tight tube. Next, prepare a 20 milligram per milliliter suspension of octadecyl silica sorbent particles by adding 1, 600 microliters of methanol followed by 400 microliters of deionized water to 40 milligrams of reversed phase sorbent in a glass vile. Tightly close the lid, and agitate with a vortex mixer.Place a nylon membrane with pore size 11 micrometers on a double layer of anti-dust tissue. Cut two small parts in the membrane with a three millimeter diameter punch. Then, grab on of the small membranes with flat end filter forceps, and place it on one side of the column.Following this, screw the flat bottom connector with the tube and tighten. Then, draw an arrow on the body of the column, pointing towards the end where the membrane was placed. At this point, secure the column on the holder with the arrow pointing towards the bottom.Attach an empty 10 milliliter disposable syringe to the end of the tube of the column by using the lower lock connectors. Agitate the sorbent suspension with the vortex mixer, and rapidly pipette 100 microliters in the center of the column. While injecting, gently aspirate the pipetted solution through the membrane by using the syringe with the other hand.The SPE column preparation is very important. You have to make sure that you properly aspirate the solution through the membrane using the syringe while injecting the particle suspension in the column. Otherwise, the particles will not be packed densely.Repeat the previous process two more times, by agitating the stock suspension between all pipetting steps, to ensure homogeneous suspension of the particles in the solution. After the entire suspension has been loaded and dried by aspirating with a syringe, keep the syringe in position and place the second nylon membrane on the top by using the forceps with the other hand. Then, screw down the second connector with a tube and dispose of the syringe.At this point, tighten the column on the SPE device by using the lower lock connectors. Connect the bottle containing the sample to the device by screwing the provided GL 45 safety cap on it. Load 200 microliters of eluent in the eluent reservoir.Then, load 800 microliters of deionized water in the dilution reservoir. Verify the pressure regulator is in the closed position by turning it reverse clockwise until further movement is not possible. After switching on the prototype, enter the values 580 for pset and 30 for delta pset.To adjust the pressure regulator, start the pump. Then, manually turn the pressure regulator until the value read for preg is inferior but close to 320 millibar. After stopping the pump, start the SPE procedure by pressing start in the automated mode corner.Once the SPE procedure is complete, close the small vile of sample and store at four to five degrees Celsius in the dark, until ELISA analysis. To clean the system, prepare a 10 milliliter solution of 70 percent methanol by volume in a glass bottle with GL 45 thread. Unplug the SPE column, and plug the tubing with connectors.In the automated mode, select the Cleaning file and start it with the same pressure settings previously used for pset, delta pset, and preg. The reproducibility of sorbent packing was evaluated by drying and weighing the pipetted sorbent in glass viles. The reproducibility of time of injection was tested for the 100 milliliter samples.The concentrations of the initial and pre-concentrated spiked samples were determined using a commercial ELISA kit of 17 beta-estradiol. It is clear from the calibration curves that the methanol ratio from the enriched sample does not effect the sensitivity of the immunoassay. Recoveries of 128, plus or minus 22 percent, and 107 plus or minus six percent, were calculated for deionized water and artificial sea water respectively.Once mastered, the preparation of an SPE column can be done in less than five minutes, if it is performed properly. The entire SPE procedure can be completed in less than one hour. After its development, this technique paved the way for researchers in the field of environmental science to explore the development of immunodetection methods for monitoring of small organic pollutants.After watching this video, you should have a good understanding of how to prepare water samples using our cost effective, automated instrument for the analysis of pollutants by immunoassays. Don't forget that working with organic pollutants and solvents can be hazardous, and precautions such as wearing appropriate gloves and protection goggles should always be taken when performing this process.

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Research

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Environment

A Small Volume Procedure for Viral Concentration from Water

Small-scale concentration of viruses (sample volumes 1-10 L, here simulated with spiked 100 ml water samples) is an efficient, cost-effective way to identify optimal parameters for virus concentration. Viruses can be concentrated from water using filtration (electropositive, electronegative, glass wool or size exclusion), followed by secondary concentration with beef extract to release viruses from filter surfaces, and finally tertiary concentration resulting in a 5-30 ml volume virus concentrate. In order to identify optimal concentration procedures, two different electropositive filters were evaluated (a glass/cellulose filter [1MDS] and a nano-alumina/glass filter [NanoCeram]), as well as different secondary concentration techniques; the celite technique where three different celite particle sizes were evaluated (fine, medium and large) followed by comparing this technique with that of the established organic flocculation method. Various elution additives were also evaluated for their ability to enhance the release of adenovirus (AdV) particles from filter surfaces. Fine particle celite recovered similar levels of AdV40 and 41 to that of the established organic flocculation method when viral spikes were added during secondary concentration. The glass/cellulose filter recovered higher levels of both, AdV40 and 41, compared to that of a nano-alumina/glass fiber filter. Although not statistically significant, the addition of 0.1% sodium polyphosphate amended beef extract eluant recovered 10% more AdV particles compared to unamended beef extract.

An approach was developed for identifying optimal viral concentration conditions for small volume water samples using spikes of human adenovirus. The techniques described here are used to identify concentration parameters for other viral targets, and applied to large-scale viral concentration experimentation.

Small-scale concentration of viruses (sample volumes 1-10 L, here simulated with spiked 100 ml water samples) is an efficient, cost-effective way to ...

EPA Method 1615. Measurement of Enterovirus and Norovirus Occurrence in Water by Culture and RT-qPCR. I. Collection of Virus Samples

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. The standardized sampling component of the method concentrates viruses that may be present in water by passage of a minimum specified volume of water through an electropositive cartridge filter. The minimum specified volumes for surface and finished/ground water are 300 L and 1,500 L, respectively. A major method limitation is the tendency for the filters to clog before meeting the sample volume requirement. Studies using two different, but equivalent, cartridge filter options showed that filter clogging was a problem with 10% of the samples with one of the filter types compared to 6% with the other filter type. Clogging tends to increase with turbidity, but cannot be predicted based on turbidity measurements only. From a cost standpoint one of the filter options is preferable over the other, but the water quality and experience with the water system to be sampled should be taken into consideration in making filter selections.

EPA Method 1615 uses an electropositive filter to concentrate enteroviruses and noroviruses in environmental and drinking waters. This manuscript describes the procedure for collecting samples for Method 1615 analyses.

EPA Method 1615 was developed with a goal of providing a standard method for measuring enteroviruses and noroviruses in environmental and drinking waters. ...

Use of Chironomidae (Diptera) Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. Unfortunately, traditional benthic larval sampling methods, such as the dip-net, can be time-consuming and expensive. An alternative protocol involves collection of Chironomidae surface-floating pupal exuviae (SFPE). Chironomidae is a species-rich family of flies (Diptera) whose immature stages typically occur in aquatic habitats. Adult chironomids emerge from the water, leaving their pupal skins, or exuviae, floating on the water&#8217;s surface. Exuviae often accumulate along banks or behind obstructions by action of the wind or water current, where they can be collected to assess chironomid diversity and richness. Chironomids can be used as important biological indicators, since some species are more tolerant to pollution than others. Therefore, the relative abundance and species composition of collected SFPE reflect changes in water quality. Here, methods associated with field collection, laboratory processing, slide mounting, and identification of chironomid SFPE are described in detail. Advantages of the SFPE method include minimal disturbance at a sampling area, efficient and economical sample collection and laboratory processing, ease of identification, applicability in nearly all aquatic environments, and a potentially more sensitive measure of ecosystem stress. Limitations include the inability to determine larval microhabitat use and inability to identify pupal exuviae to species if they have not been associated with adult males.

Use of Chironomidae Diptera Surface-Floating Pupal Exuviae as a Rapid Bioassessment Protocol for Water Bodies

Rapid bioassessment protocols using benthic macroinvertebrates are often used to monitor and assess water quality. An efficient protocol involves collections of Chironomidae surface-floating pupal exuviae (SFPE). Here, techniques for field collection, laboratory processing, slide mounting, and identification of Chironomidae SFPE are described.

Rapid bioassessment protocols using benthic macroinvertebrate assemblages have been successfully used to assess human impacts on water quality. ...

Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. 
In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

This manuscript describes an automated gel size selection approach for purifying DNA fragments for next-generation sequencing. The Ranger Technology provides complete automation of the entire process of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments allowing for high-throughput and high quality next-generation sequencing libraries.

Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA ...

Use of a Filter Cartridge for Filtration of Water Samples and Extraction of Environmental DNA

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies employed disk fiber filters to collect eDNA from water samples, although a number of microbial studies in aquatic environments have employed filter cartridges, because the cartridge has the advantage of accommodating large water volumes and of overall ease of use. Here we provide a protocol for filtration of water samples using the filter cartridge and extraction of eDNA from the filter without having to cut open the housing. The main portions of this protocol consists of 1) filtration of water samples (water volumes &#8804;4 L or &gt;4 L); (2) extraction of DNA on the filter using a roller shaker placed in a preheated incubator; and (3) purification of DNA using a commercial kit. With the use of this and previously-used protocols, we perform metabarcoding analysis of eDNA taken from a huge aquarium tank (7,500 m3) with known species composition, and show the number of detected species per library from the two protocols as the representative results. This protocol has been developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

We describe a protocol for filtration of water samples with a filter cartridge and extraction of environmental DNA (eDNA) without having to cut open the housing to remove the filter. This protocol is developed for metabarcoding eDNA from fishes, but is also applicable to eDNA from other organisms.

Recent studies demonstrated the use of environmental DNA (eDNA) from fishes to be appropriate as a non-invasive monitoring tool. Most of these studies ...

A Lipid Extraction and Analysis Method for Characterizing Soil Microbes in Experiments with Many Samples

Microbial communities are important drivers and regulators of ecosystem processes. To understand how management of ecosystems may affect microbial communities, a relatively precise but effort-intensive technique to assay microbial community composition is phospholipid fatty acid (PLFA) analysis. PLFA was developed to analyze phospholipid biomarkers, which can be used as indicators of microbial biomass and the composition of broad functional groups of fungi and bacteria. It has commonly been used to compare soils under alternative plant communities, ecology, and management regimes. The PLFA method has been shown to be sensitive to detecting shifts in microbial community composition.
An alternative method, fatty acid methyl ester extraction and analysis (MIDI-FA) was developed for rapid extraction of total lipids, without separation of the phospholipid fraction, from pure cultures as a microbial identification technique. This method is rapid but is less suited for soil samples because it lacks an initial step separating soil particles and begins instead with a saponification reaction that likely produces artifacts from the background organic matter in the soil. 
This article describes a method that increases throughput while balancing effort and accuracy for extraction of lipids from the cell membranes of microorganisms for use in characterizing both total lipids and the relative abundance of indicator lipids to determine soil microbial community structure in studies with many samples. The method combines the accuracy achieved through PLFA profiling by extracting and concentrating soil lipids as a first step, and a reduction in effort by saponifying the organic material extracted and processing with the MIDI-FA method as a second step.

The article describes a method that increases throughput while balancing effort and accuracy for extraction of lipids from the cell membranes of microorganisms for use in characterizing both total lipids and the relative abundance of indicator lipids to determine soil microbial community structure in studies with many samples.

Microbial communities are important drivers and regulators of ecosystem processes. To understand how management of ecosystems may affect microbial ...

Extraction of Organochlorine Pesticides from Plastic Pellets and Plastic Type Analysis

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment during manufacturing and transport. Because of their environmental persistence, they are widely distributed in the oceans and on beaches all over the world. They can act as a vector of potentially toxic organic compounds (e.g., polychlorinated biphenyls) and might consequently negatively affect marine organisms. Their possible impacts along the food chain are not yet well understood. In order to assess the hazards associated with the occurrence of plastic pellets in the marine environment, it is necessary to develop methodologies that allow for rapid determination of associated organic contaminant levels. The present protocol describes the different steps required for sampling resin pellets, analyzing adsorbed organochlorine pesticides (OCPs) and identifying the plastic type. The focus is on the extraction of OCPs from plastic pellets by means of a pressurized fluid extractor (PFE) and on the polymer chemical analysis applying Fourier Transform-InfraRed (FT-IR) spectroscopy. The developed methodology focuses on 11 OCPs and related compounds, including dichlorodiphenyltrichloroethane (DDT) and its two main metabolites, lindane and two production isomers, as well as the two biologically active isomers of technical endosulfan. This protocol constitutes a simple and rapid alternative to existing methodology for evaluating the concentration of organic contaminants adsorbed on plastic pieces.

Microplastics act as vector of potentially toxic organic contaminants with unpredictable effects. This protocol describes an alternative methodology for assessing the levels of organochlorine pesticides adsorbed on plastic pellets and identifying the polymer chemical structure. The focus is on pressurized fluid extraction and attenuated total reflectance Fourier transform infrared spectroscopy.

Plastic resin pellets, categorized as microplastics (&#8804;5 mm in diameter), are small granules that can be unintentionally released to the environment ...

A Simple Planting Technique for Re-establishing Trees Where Frequent Inundation Occurs

Many of the Everglades tree islands have lost elevation over the past century and most of their trees have died such that they are now covered with herbaceous plants. This protocol describes a simple, cost-effective tree planting technique needed for restoring degraded Everglade tree islands. The design is patterned after a natural Everglades process that creates floating peat islands, which allows tree survival and growth in flooded conditions and often leads to the development of tree islands. Commercially available peat bags were used as the medium for the growth and establishment of potted native tree saplings. The pop-up configuration floated initially and provided additional elevation to minimize inundation, with a single native tree species sapling and a single tree fertilizer spike. During a 3 year study involving 105 pop-ups, most plants survived (80%) and many thrived. Determining whether this technique can establish trees on a degraded tree island will require longer studies and extensive field tests.

This protocol describes a simple, cost-effective tree planting technique for restoring degraded Everglades tree islands that experience inundation. The design creates an island (pop-up) which floats initially and adds elevation to promote tree survival and growth under flooded conditions.

Many of the Everglades tree islands have lost elevation over the past century and most of their trees have died such that they are now covered with ...

Collection and Extraction of Occupational Air Samples for Analysis of Fungal DNA

Traditional methods of identifying fungal exposures in occupational environments, such as culture and microscopy-based approaches, have several limitations that have resulted in the exclusion of many species. Advances in the field over the last two decades have led occupational health researchers to turn to molecular-based approaches for identifying fungal hazards. These methods have resulted in the detection of many species within indoor and occupational environments that have not been detected using traditional methods. This protocol details an approach for determining fungal diversity within air samples through genomic DNA extraction, amplification, sequencing, and taxonomic identification of fungal internal transcribed spacer (ITS) regions. ITS sequencing results in the detection of many fungal species that are either not detected or difficult to identify to species level using culture or microscopy. While these methods do not provide quantitative measures of fungal burden, they offer a new approach to hazard identification and can be used to determine overall species richness and diversity within an occupational environment.

Determining the fungal diversity within an environment is a method utilized in occupational health studies to identify health hazards. This protocol describes DNA extraction from occupational air samples for amplification and sequencing of fungal ITS regions. This approach detects many fungal species that can be overlooked by traditional assessment methods.

Traditional methods of identifying fungal exposures in occupational environments, such as culture and microscopy-based approaches, have several ...

Optimized Procedure for Determining the Adsorption of Phosphonates onto Granular Ferric Hydroxide using a Miniaturized Phosphorus Determination Method

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide (GFH), with little effort and high reliability. The phosphonate, e.g., nitrilotrimethylphosphonic acid (NTMP), is brought into contact with the GFH in a rotator in a solution buffered by an organic acid (e.g., acetic acid) or Good buffer (e.g., 2-(N-morpholino)ethanesulfonic acid) [MES] and N-cyclohexyl-2-hydroxyl-3-aminopropanesulfonic acid [CAPSO]) in a concentration of 10 mM for a specific time in 50 mL centrifuge tubes. Subsequently, after membrane filtration (0.45 &#181;m pore size), the total phosphorus (total P) concentration is measured using a specifically developed determination method (ISOmini). This method is a modification and simplification of the ISO 6878 method: a 4 mL sample is mixed with H2SO4 and K2S2O8 in a screw cap vial, heated to 148-150 &#176;C for 1 h and then mixed with NaOH, ascorbic acid and acidified molybdate with antimony(III) (final volume of 10 mL) to produce a blue complex. The color intensity, which is linearly proportional to the phosphorus concentration, is measured spectrophotometrically (880 nm). It is demonstrated that the buffer concentration used has no significant effect on the adsorption of phosphonate between pH 4 and 12. The buffers, therefore, do not compete with the phosphonate for adsorption sites. Furthermore, the relatively high concentration of the buffer requires a higher dosage concentration of oxidizing agent (K2S2O8) for digestion than that specified in ISO 6878, which, together with the NaOH dosage, is matched to each buffer. Despite the simplification, the ISOmini method does not lose any of its accuracy compared to the standardized method.

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric hydroxide, with little effort and high reliability. In a buffered solution, the phosphonate is brought into contact with the adsorbent using a rotator and then analyzed via a miniaturized phosphorus determination method.

This paper introduces a procedure to investigate the adsorption of phosphonates onto iron-containing filter materials, particularly granular ferric ...