http://lod.bco-dmo.org/id/dataset/1009219 eng; USA utf8 dataset Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact 2026-10-06 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Fenton oxidation of particulate terrestrial organic matter (TOM) samples and sequential POM/DOM fractionation 2026-10-08 publication 2026-10-08 revision BCO-DMO Linked Data URI 2026-10-08 creation http://lod.bco-dmo.org/id/dataset/1009219 Patrick G. Hatcher Old Dominion University principalInvestigator Aleksandar I. Goranov Old Dominion University principalInvestigator Ann Pearson Harvard University principalInvestigator Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. publisher Cite this dataset as: Goranov, A. I., Carter, S. J., Pearson, A., Hatcher, P. G. (2026) Fenton oxidation of particulate terrestrial organic matter (TOM) samples and sequential POM/DOM fractionation. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-10-08 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/1009219 [access date] TOM Fenton oxidation Dataset Description: Methods and Sampling: &lt;p&gt;&lt;strong&gt;Hillsborough Soil&lt;/strong&gt;: a riverbank soil of the Hillsborough River (Florida). The river arises from the Green Swamp, also known as the “Heart of the Floridan Aquifer”, and flows 60 miles to an outlet in the city of Tampa on Hillsborough Bay. Its watershed was formerly covered by a rich, old-growth forest of Bald Cypress, Longleaf Pine, and Sand Live Oak. After decades of logging, the watershed’s cover has shifted to recently grown Water Ash and Water Locust trees. The soil was collected on 02 April 2019 at coordinates 28° 05′ 16.8″ N and 82° 20′ 56.3″ W. After removal of large debris, the soil was homogenized, sieved, oven-dried at 105 °C, and stored in the dark to prevent degradation during storage.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Elliott Soil&lt;/strong&gt;: a standardized fertile prairie soil purchased from the International Humic Substances Society (IHSS). This sample was obtained from an undisturbed area on the grounds of the Joliet Army Ammunition Plant near Joliet, Illinois, currently managed by the US Forest Service as the Midewin National Tallgrass Prairie Reserve. It is a poorly drained soil on moraines and till plains having loess or silty clay loam glacial till.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Pahokee Peat&lt;/strong&gt;: a standardized peat soil purchased from the IHSS. It is an agricultural soil of the Florida Everglades obtained from the University of Florida Belle Glade Research Station. This is a poorly drained soil formed by organic deposits from freshwater marshes accumulating over limestone bedrock.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Great Dismal Swamp Peat&lt;/strong&gt;: a peat from a blackwater wetland in Virginia that has high iron loadings. Its hydric soils are formed under repeated saturation, long enough to develop anaerobic conditions in the upper horizons. The peat is formed by fast accumulation of carbon and slow decomposition yielding an organic-rich peat (Sleeter et al., 2017).&lt;br /&gt; &lt;br /&gt; &lt;strong&gt;Elemental and Isotopic Characterization&lt;/strong&gt;: Samples were prepared for total organic carbon (TOC) and isotopic composition (δ13C) analysis by wrapping weighed amounts of sample in tin capsules. Analysis was performed using a Thermo-Scientific Flash EA instrument (combustion at 1010 °C) equipped with a thermal conductivity detector and a Delta V Plus isotope-ratio mass spectrometer. The instrument's performance is validated daily by analysis of standards (mentioned below). TOC and δ13C values were obtained in duplicate (technical replicates). TOC values were obtained after calibration with the isotopic standards below. Carbon peak integrations are done automatically by the instrument and peak areas are related to C amounts using calibration curves in Excel. δ13C values determined by the isotope-ratio mass spectrometer and computed by its software were peak-size-corrected and scale-corrected (in Excel using calibration curves) using laboratory and authentic reference standards (glutamic acid: δ13C = −13.90‰; USGS40: δ13C = −26.39‰; USGS41a: δ13C = +36.55‰; and tyrosine: δ13C = −24.90‰). δ13C results are reported in delta notation relative to that of Vienna Pee Dee Belemnite.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Oxidation experiments. &lt;/strong&gt;Oxidation of TOM samples was performed by suspending 1-4 g of dried material (105 °C for 12 h) in 10-20 mL of 1 M H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; (Fisher, 30%), with iron concentrations unperturbed from the native sample compositions. Control experiments were done similarly but with ultrapure water (18.2 MΩ·cm). Experiments were performed in acid-cleaned and pre-combusted 60 mL glass vials, which were kept open to the air to ensure constant aeration and steady gas release, avoiding pressure buildup. As the &amp;nbsp;soil samples were largely insoluble in water, once the aqueous H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; was added to the soils, vials were sonicated for 30 minutes to ensure proper mixing and breakage of any formed clumps. The formed suspensions were let react for 48 h at room temperature in a shaking incubator (vials were covered with a large KimWipe). Then, the vials were frozen at -80 °C (to quench the oxidation) and the liquid was removed by freeze-drying (with the freeze drier maintaining temperature of -60 to -80 °C). Then, new 10-20 mL of peroxide were added for another 48 hours.&amp;nbsp;&lt;/p&gt; &lt;p&gt;Oxidation was performed for up to six consecutive 48-hour cycles, for a total of 288 hours. Samples were analyzed at 10 time points: 0, 12, 24, 36, 48, 96, 144, 192, 240, and 288 hours. The 12-, 24-, and 36-hour measurements were collected during the first oxidation cycle, while subsequent measurements corresponded to the completion of each 48-hour cycle. Oxidation times represent cumulative exposure to the oxidation treatment.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;POM/DOM fractionation.&lt;/strong&gt; After the suspensions were freeze-dried, the obtained OM was fractionated into POM and DOM via water-extraction: the OM residue was suspended in 20 mL of ultrapure water. Suspensions were sonicated for 30 min to ensure proper mixing and then placed on a shaking incubator. After 48 hours the suspensions were quantitatively transferred into pre-cleaned plastic falcon tubes. Following centrifugation, the supernatant liquid (containing the DOM) was decanted into a filter manifold (0.45 µm pre-combusted GFF) and then the remaining POM was resuspended in 20 mL water to wash the POM of any remaining DOM. The new suspension was centrifuged again, and the water wash was decanted into the filter manifold. The falcon tubes, containing the POM fraction, as well as the decanted and filtered DOM fractions, were freeze-dried.&amp;nbsp;&lt;/p&gt; &lt;p&gt;The resultant DOM and POM powders were homogenized. Then, about 50 mg of each sample was digested with 1 mL of 20% HCl to remove refractory carbonates such as siderite (Larson et al., 2008). The acid was evaporated at 80 °C (O’Kelly, 2005) and samples were homogenized again prior to analysis.&lt;/p&gt; Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2346285 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2346285 onGoing Patrick G. Hatcher Old Dominion University 614-323-8799 4402 Elkhorn Ave. Department of Chemistry and Biochemistry Norfolk VA 23529 USA phatcher@odu.edu pointOfContact Aleksandar I. Goranov Old Dominion University 3000A Chemistry Building 4501 Elkhorn Ave. Norfolk VA 23529 USA aleksandar.i.goranov@gmail.com pointOfContact Ann Pearson Harvard University 617-384-8392 Hoffman Lab G13 20 Oxford St. Cambridge MA 02138 USA pearson@eps.harvard.edu pointOfContact asNeeded Dataset Version: 1 Unknown sample_name oxidation_time_hours pom_d13c_avg pom_d13c_stdev pom_c_percent_avg pom_c_percent_stdev dom_d13c_avg dom_d13c_stdev dom_c_percent_avg dom_c_percent_stdev centrifuge oven Thermo-Scientific Flash EA instrument homogenizer shaking incubator Delta V Plus isotope-ratio mass spectrometer sonicated theme None, User defined sample identification time_elapsed 13C, stable isotope of C standard deviation Elemental carbon (C) featureType BCO-DMO Standard Parameters Centrifuge Drying Oven Elemental Analyzer Homogenizer Shaker Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer ultrasonic cell disrupter (sonicator) instrument BCO-DMO Standard Instruments otherRestrictions otherRestrictions Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use. EAGER: The camouflaging of terrigenous organic matter as marine organic matter through hydroxyl radical oxidation via the dark Fenton reaction https://osprey.bco-dmo.org/project/941590 EAGER: The camouflaging of terrigenous organic matter as marine organic matter through hydroxyl radical oxidation via the dark Fenton reaction <p><em>NSF Award Abstract:</em><br /> Organic carbon in the ocean is made-up of materials delivered by riverine runoff from land and marine sources. However, even though a large amount of land-derived organic carbon enters the ocean from rivers, most carbon in the ocean appears to be from marine sources. This has led scientists to conclude that land-derived carbon is not transported far into the ocean. This EAGER project aims to test this assumption. The team of scientists will examine whether chemical reactions alter the composition of land-derived organic carbon in a way that makes it look like marine organic carbon. If this proves true, the results could explain why land-derived organic carbon is difficult to identify in the ocean and could lead to a reconsideration of present carbon budgets and models. The scientists will perform experiments using land-derived carbon collected from major river systems throughout the world. Samples will be introduced to reactive oxygen species (mainly hydroxyl radicals) and iron in the dark under conditions that occur in nature. Reaction rates and changes in the composition of the organic matter will be monitored during and following the experiments. This EAGER project provides research training and valuable professional development experience for an early career researcher who has not received prior support from NSF. Undergraduate students enrolled in STEM and REU programs at the lead institutions will participate in the research.</p> <p>This EAGER project examines the hypothesis that hydroxyl radicals generated during dark Fenton reactions react with terrigenous organic matter to produce organic matter that is compositionally and isotopically similar to marine organic matter. The PIs will test this hypothesis using environmentally relevant concentrations of hydroxyl radical and terrestrial organic matter samples collected from several large-scale terrestrial riverine systems. The PIs will use multiple methods to characterize bulk organic matter (infrared/nuclear magnetic resonance (NMR) spectroscopy), its molecular composition (electrospray ionization Fourier Transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS), and stable isotope values of carbon and nitrogen (δ13C, δ15N) of dissolved and particulate organic matter pools before, during and following the experiments. This study explores an untested, but potentially transformative hypothesis that could alter existing paradigms about the fate of terrestrial organic matter in the ocean. Results from this study could revise understanding of the contributions of terrigenous organic matter to the ocean carbon cycle. The project would provide research and professional development opportunities for an early career investigator who has not received prior NSF support (co-PI Goranov). Undergraduates enrolled in REU and STEM training programs at the PIs’ home institutions would participate in the research.</p> <p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p> Fenton oxidation largerWorkCitation project eng; USA biota oceans -88.1121 -76.5251 26.6834 41.3767 2026-10-08 0 BCO-DMO catalogue of parameters from Fenton oxidation of particulate terrestrial organic matter (TOM) samples and sequential POM/DOM fractionation Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact http://lod.bco-dmo.org/id/dataset-parameter/1009289.rdf Name: sample_name Units: unitless Description: <p>Name of the sample used for oxidation</p> http://lod.bco-dmo.org/id/dataset-parameter/1009290.rdf Name: oxidation_time_hours Units: hours Description: <p>Cumulative oxidation time in hours, including intermediate measurements at 12, 24, and 36 hours during the first 48-hour oxidation cycle and measurements at the completion of each subsequent 48-hour cycle, up to 288 hours.</p> http://lod.bco-dmo.org/id/dataset-parameter/1009291.rdf Name: pom_d13c_avg Units: per mille (‰) Description: <p>Stable carbon isotopic signature (δ13C) that is an average (AVG) of two technical replicates for the particulate organic matter (POM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009292.rdf Name: pom_d13c_stdev Units: per mille (‰) Description: <p>Standard deviation (STDEV) of the stable carbon isotopic signature (δ13C) of two technical replicates of the particulate organic matter (POM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009293.rdf Name: pom_c_percent_avg Units: percentage (%) Description: <p>Amount of carbon that is an average (AVG) of two technical replicates for the particulate organic matter (POM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009294.rdf Name: pom_c_percent_stdev Units: percentage (%) Description: <p>Standard deviation (STDEV) of the amount of carbon in two technical replicates of the particulate organic matter (POM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009295.rdf Name: dom_d13c_avg Units: per mille (‰) Description: <p>Stable carbon isotopic signature (δ13C) that is an average (AVG) of two technical replicates for the dissolved organic matter (DOM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009296.rdf Name: dom_d13c_stdev Units: per mille (‰) Description: <p>Standard deviation (STDEV) of the stable carbon isotopic signature (δ13C) of two technical replicates of the dissolved organic matter (DOM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009297.rdf Name: dom_c_percent_avg Units: percentage (%) Description: <p>Amount of carbon that is an average (AVG) of two technical replicates for the dissolved organic matter (DOM) fraction</p> http://lod.bco-dmo.org/id/dataset-parameter/1009298.rdf Name: dom_c_percent_stdev Units: percentage (%) Description: <p>Standard deviation (STDEV) of the amount of carbon in two technical replicates of the dissolved organic matter (DOM) fraction</p> GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact https://osprey.bco-dmo.org/dataset/1009219/data/download download onLine dataset &lt;p&gt;&lt;strong&gt;Hillsborough Soil&lt;/strong&gt;: a riverbank soil of the Hillsborough River (Florida). The river arises from the Green Swamp, also known as the “Heart of the Floridan Aquifer”, and flows 60 miles to an outlet in the city of Tampa on Hillsborough Bay. Its watershed was formerly covered by a rich, old-growth forest of Bald Cypress, Longleaf Pine, and Sand Live Oak. After decades of logging, the watershed’s cover has shifted to recently grown Water Ash and Water Locust trees. The soil was collected on 02 April 2019 at coordinates 28° 05′ 16.8″ N and 82° 20′ 56.3″ W. After removal of large debris, the soil was homogenized, sieved, oven-dried at 105 °C, and stored in the dark to prevent degradation during storage.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Elliott Soil&lt;/strong&gt;: a standardized fertile prairie soil purchased from the International Humic Substances Society (IHSS). This sample was obtained from an undisturbed area on the grounds of the Joliet Army Ammunition Plant near Joliet, Illinois, currently managed by the US Forest Service as the Midewin National Tallgrass Prairie Reserve. It is a poorly drained soil on moraines and till plains having loess or silty clay loam glacial till.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Pahokee Peat&lt;/strong&gt;: a standardized peat soil purchased from the IHSS. It is an agricultural soil of the Florida Everglades obtained from the University of Florida Belle Glade Research Station. This is a poorly drained soil formed by organic deposits from freshwater marshes accumulating over limestone bedrock.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Great Dismal Swamp Peat&lt;/strong&gt;: a peat from a blackwater wetland in Virginia that has high iron loadings. Its hydric soils are formed under repeated saturation, long enough to develop anaerobic conditions in the upper horizons. The peat is formed by fast accumulation of carbon and slow decomposition yielding an organic-rich peat (Sleeter et al., 2017).&lt;br /&gt; &lt;br /&gt; &lt;strong&gt;Elemental and Isotopic Characterization&lt;/strong&gt;: Samples were prepared for total organic carbon (TOC) and isotopic composition (δ13C) analysis by wrapping weighed amounts of sample in tin capsules. Analysis was performed using a Thermo-Scientific Flash EA instrument (combustion at 1010 °C) equipped with a thermal conductivity detector and a Delta V Plus isotope-ratio mass spectrometer. The instrument's performance is validated daily by analysis of standards (mentioned below). TOC and δ13C values were obtained in duplicate (technical replicates). TOC values were obtained after calibration with the isotopic standards below. Carbon peak integrations are done automatically by the instrument and peak areas are related to C amounts using calibration curves in Excel. δ13C values determined by the isotope-ratio mass spectrometer and computed by its software were peak-size-corrected and scale-corrected (in Excel using calibration curves) using laboratory and authentic reference standards (glutamic acid: δ13C = −13.90‰; USGS40: δ13C = −26.39‰; USGS41a: δ13C = +36.55‰; and tyrosine: δ13C = −24.90‰). δ13C results are reported in delta notation relative to that of Vienna Pee Dee Belemnite.&amp;nbsp;&lt;/p&gt; &lt;p&gt;&lt;strong&gt;Oxidation experiments. &lt;/strong&gt;Oxidation of TOM samples was performed by suspending 1-4 g of dried material (105 °C for 12 h) in 10-20 mL of 1 M H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; (Fisher, 30%), with iron concentrations unperturbed from the native sample compositions. Control experiments were done similarly but with ultrapure water (18.2 MΩ·cm). Experiments were performed in acid-cleaned and pre-combusted 60 mL glass vials, which were kept open to the air to ensure constant aeration and steady gas release, avoiding pressure buildup. As the &amp;nbsp;soil samples were largely insoluble in water, once the aqueous H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt; was added to the soils, vials were sonicated for 30 minutes to ensure proper mixing and breakage of any formed clumps. The formed suspensions were let react for 48 h at room temperature in a shaking incubator (vials were covered with a large KimWipe). Then, the vials were frozen at -80 °C (to quench the oxidation) and the liquid was removed by freeze-drying (with the freeze drier maintaining temperature of -60 to -80 °C). Then, new 10-20 mL of peroxide were added for another 48 hours.&amp;nbsp;&lt;/p&gt; &lt;p&gt;Oxidation was performed for up to six consecutive 48-hour cycles, for a total of 288 hours. Samples were analyzed at 10 time points: 0, 12, 24, 36, 48, 96, 144, 192, 240, and 288 hours. The 12-, 24-, and 36-hour measurements were collected during the first oxidation cycle, while subsequent measurements corresponded to the completion of each 48-hour cycle. Oxidation times represent cumulative exposure to the oxidation treatment.&lt;/p&gt; &lt;p&gt;&lt;strong&gt;POM/DOM fractionation.&lt;/strong&gt; After the suspensions were freeze-dried, the obtained OM was fractionated into POM and DOM via water-extraction: the OM residue was suspended in 20 mL of ultrapure water. Suspensions were sonicated for 30 min to ensure proper mixing and then placed on a shaking incubator. After 48 hours the suspensions were quantitatively transferred into pre-cleaned plastic falcon tubes. Following centrifugation, the supernatant liquid (containing the DOM) was decanted into a filter manifold (0.45 µm pre-combusted GFF) and then the remaining POM was resuspended in 20 mL water to wash the POM of any remaining DOM. The new suspension was centrifuged again, and the water wash was decanted into the filter manifold. The falcon tubes, containing the POM fraction, as well as the decanted and filtered DOM fractions, were freeze-dried.&amp;nbsp;&lt;/p&gt; &lt;p&gt;The resultant DOM and POM powders were homogenized. Then, about 50 mg of each sample was digested with 1 mL of 20% HCl to remove refractory carbonates such as siderite (Larson et al., 2008). The acid was evaporated at 80 °C (O’Kelly, 2005) and samples were homogenized again prior to analysis.&lt;/p&gt; Specified by the Principal Investigator(s) &lt;p&gt;Data was processed first by the instrument's software and then in Microsoft Excel.&lt;/p&gt; Specified by the Principal Investigator(s) This section documents curation actions performed prior to publication review with the submitter, and additional information relevant to understanding and reusing this dataset. It distinguishes changes made to the submitted (meta)data from unresolved issues and/or enhancements that improve future reuse and interoperability. CURATION ACTIONS PERFORMED ON DATA - Loaded TOM Fenton Oxidation POM-DOM fractionation BCO-DMO.xlsx (sheet1), header row 1, missing values &quot;&quot; and &quot;nd&quot; treated as null - Renamed columns: Sample Name to sample_name, Oxidation Time, hours to oxidation_time_hours, POM d13C AVG to pom_d13c_avg, POM d13C STDEV to pom_d13c_stdev, POM C% AVG to pom_c_percent_avg, POM C% STDEV to pom_c_percent_stdev, DOM d13C AVG to dom_d13c_avg, DOM d13C STDEV to dom_d13c_stdev, DOM C% AVG to dom_c_percent_avg, DOM C% STDEV to dom_c_percent_stdev - Output file as 1009219_v1_pom_dom_fenton_oxidation.csv CURATION ACTIONS PERFORMED ON METADATA - BCO-DMO's standard metadata entry and text formatting steps were performed. See: https://www.bco-dmo.org/how-to/standard-curation-edits - Added detail about sampling times during the experiment ISSUES POTENTIALLY IMPACTING REUSE - No soil sampling dates or ranges are provided. The methods would benefit from clarification of the general dates/time periods of collection and description of collection methods in cases where samples were not purchased. - Dataset values are derived (averaged) values, based on the observations. The complete data is not referenced or provided as part of this submission. Specified by BCO-DMO Data Managers asNeeded 7.x-1.1 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact centrifuge centrifuge PI Supplied Instrument Name: centrifuge PI Supplied Instrument Description:Following centrifugation, the supernatant liquid (containing the DOM) was decanted into a filter manifold (0.45 µm pre-combusted GFF) and then the remaining POM was resuspended in 20 mL water to wash the POM of any remaining DOM. The new suspension was centrifuged again, and the water wash was decanted into the filter manifold. The falcon tubes, containing the POM fraction, as well as the decanted and filtered DM fractions, were freeze-dried.  Instrument Name: Centrifuge Instrument Short Name: Instrument Description: A machine with a rapidly rotating container that applies centrifugal force to its contents, typically to separate fluids of different densities (e.g., cream from milk) or liquids from solids. oven oven PI Supplied Instrument Name: oven PI Supplied Instrument Description:After removal of large debris, the soil was homogenized, sieved, oven-dried at 105 °C, and stored in the dark to prevent degradation during storage. Instrument Name: Drying Oven Instrument Short Name: Instrument Description:  a heated chamber for drying Thermo-Scientific Flash EA instrument Thermo-Scientific Flash EA instrument PI Supplied Instrument Name: Thermo-Scientific Flash EA instrument PI Supplied Instrument Description:Elemental and Isotopic Characterization. Samples were prepared for total organic carbon (TOC) and isotopic composition (δ13C) analysis by wrapping weighed amounts of sample in tin capsules. Analysis was performed using a Thermo-Scientific Flash EA instrument (combustion at 1010 °C) equipped with a thermal conductivity detector and a Delta V Plus isotope-ratio mass spectrometer. The instrument's performance is validated daily by analysis of standards (mentioned below). TOC and δ13C values were obtained in duplicate (technical replicates). TOC values were obtained after calibration with the isotopic standards below. Carbon peak integrations are done automatically by the instrument and peak areas are related to C amounts using calibration curves in Excel. δ13C values determined by the isotope-ratio mass spectrometer and computed by its software were peak-size-corrected and scale-corrected (in Excel using calibration curves) using laboratory and authentic reference standards (glutamic acid: δ13C = −13.90‰; USGS40: δ13C = −26.39‰; USGS41a: δ13C = +36.55‰; and tyrosine: δ13C = −24.90‰). δ13C results are reported in delta notation relative to that of Vienna Pee Dee Belemnite.  Instrument Name: Elemental Analyzer Instrument Short Name: Instrument Description: Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/ homogenizer homogenizer PI Supplied Instrument Name: homogenizer PI Supplied Instrument Description:After removal of large debris, the soil was homogenized, sieved, oven-dried at 105 °C, and stored in the dark to prevent degradation during storage. Instrument Name: Homogenizer Instrument Short Name:Homogenizer Instrument Description: A homogenizer is a piece of laboratory equipment used for the homogenization of various types of material, such as tissue, plant, food, soil, and many others. shaking incubator shaking incubator PI Supplied Instrument Name: shaking incubator PI Supplied Instrument Description:The formed suspensions were let react for 48 h at room temperature in on a shaking incubator (vials were covered with a large KimWipe). Instrument Name: Shaker Instrument Short Name: Instrument Description: A Shaker is a piece of lab equipment used to mix, blend, or to agitate substances in tube(s) or flask(s) by shaking them, which is mainly used in the fields of chemistry and biology. A shaker contains an oscillating board which is used to place the flasks, beakers, test tubes, etc. Delta V Plus isotope-ratio mass spectrometer Delta V Plus isotope-ratio mass spectrometer PI Supplied Instrument Name: Delta V Plus isotope-ratio mass spectrometer PI Supplied Instrument Description:Elemental and Isotopic Characterization. Samples were prepared for total organic carbon (TOC) and isotopic composition (δ13C) analysis by wrapping weighed amounts of sample in tin capsules. Analysis was performed using a Thermo-Scientific Flash EA instrument (combustion at 1010 °C) equipped with a thermal conductivity detector and a Delta V Plus isotope-ratio mass spectrometer. The instrument's performance is validated daily by analysis of standards (mentioned below). TOC and δ13C values were obtained in duplicate (technical replicates). TOC values were obtained after calibration with the isotopic standards below. Carbon peak integrations are done automatically by the instrument and peak areas are related to C amounts using calibration curves in Excel. δ13C values determined by the isotope-ratio mass spectrometer and computed by its software were peak-size-corrected and scale-corrected (in Excel using calibration curves) using laboratory and authentic reference standards (glutamic acid: δ13C = −13.90‰; USGS40: δ13C = −26.39‰; USGS41a: δ13C = +36.55‰; and tyrosine: δ13C = −24.90‰). δ13C results are reported in delta notation relative to that of Vienna Pee Dee Belemnite.  Instrument Name: Thermo Fisher Scientific DELTA V Plus isotope ratio mass spectrometer Instrument Short Name:Delta V Plus IRMS Instrument Description: The Thermo Scientific DELTA V Plus is an isotope ratio mass spectrometer designed to measure isotopic, elemental and molecular ratios of organic and inorganic compounds. The DELTA V Plus is an enhanced model of the DELTA V series of isotope ratio mass spectrometers, which can be upgraded from the DELTA V Advantage. The DELTA V Plus can be operated in Continuous Flow or Dual Inlet mode and can accommodate up to 10 collectors, ensuring flexibility to cover many applications. The DELTA V Plus is controlled by an automated, integrated Isodat software suite. A magnet, whose pole faces determine the free flight space for the ions, eliminates the traditional flight tube. The magnet is designed for fast mass switching which is further supported by a fast jump control between consecutive measurements of multiple gases within one run. The sample gas is introduced at ground potential, eliminating the need for insulation of the flow path, ensuring 100 percent transfer into the ion source. The amplifiers register ion beams up to 50 V. The DELTA V Plus has refined optics, enabling greater ion transmission than the DELTA V Advantage. It has a sensitivity of 800 molecules per ion (M/I) in Dual Inlet mode and 1100 M/I in Continuous Flow mode. It has a system stability of < 10 ppm and an effective magnetic detection radius of 191 nm. It has a mass range of 1 - 96 Dalton at 3 kV. sonicated sonicated PI Supplied Instrument Name: sonicated PI Supplied Instrument Description:As the  soil samples were largely insoluble in water, once the aqueous H2O2 was added to the soils, vials were sonicated for 30 minutes to ensure proper mixing and breakage of any formed clumps. Instrument Name: ultrasonic cell disrupter (sonicator) Instrument Short Name: Instrument Description: Instrument that applies sound energy to agitate particles in a sample.