The Experts below are selected from a list of 282 Experts worldwide ranked by ideXlab platform

Patrick Raimbault - One of the best experts on this subject based on the ideXlab platform.

  • Simultaneous determination of Particulate Organic carbon, Nitrogen and phosphorus collected on filters, using a semi-automatic wet-oxidation method
    Marine Ecology Progress Series, 1999
    Co-Authors: Patrick Raimbault, W Pouvesle, Frédéric Diaz, Bilal Boudjellal
    Abstract:

    A wet-oxidation method is presented for determining simultaneously Particulate Organic carbon (POC), Particulate Organic Nitrogen (PON) and Particulate Organic phosphorus (POP) collected on filters. Conversion of POC, PON and POP to inOrganic products, carbon dioxide, nitrate+nitrite and soluble reactive phosphate respectively, is performed by a persulfate wet-oxidation in slight alkaline condition. After oxidation, inOrganic products are dissolved in the digestion mixture and concentrations are measured automatically by colorimetry using a 3 channel Technicon AutoAnalyzer(R). Concurrent comparisons were made with dry combustion at 950 degrees C for POC and PON (CHN analysis) and with former wet-oxidation procedure for POP. Results indicated high efficiency to oxidize natural suspended Particulate matter from sea- and freshwater as well as phytoplankton cultures and sinking particles collected by sediment traps. This method also exhibits good reliability and precision in comparison with former procedures and is highly suitable for routine analysis and especially appropriate for shipboard work.

  • a semiautomatic wet oxidation method for the determination of Particulate Organic Nitrogen collected on filters
    Limnology and Oceanography, 1991
    Co-Authors: Patrick Raimbault, Gerd Slawyk
    Abstract:

    A wet-oxidation method with peroxydisulfate digestion at 120°C is presented for routine analysis of Particulate Organic N (PON) collected on glass-fiber filters. The technique was adapted from a previous procedure for oxidizing total N in seawater to NO3− . Comparisons with PON determinations by dry combustion at 800°C indicated high efficiency of the procedure, giving 100% recovery of N with cell cultures and natural seawater samples. Neutralizing buffer and pH adjustment proved to be necessary but were simplified by using a Technicon AutoAnalyzer system. The method was applied to follow NO3−assimilation by phytoplankton cultures and revealed excretion of N compounds by the cells at the end of the exponential phase of growth. The sensitivity of the method makes it possible to filter smaller quantities of seawater than needed for the combustion method (by 1–2 orders of magnitude) and can easily be adapted to shipboard use.

  • A semiautomatic, wet‐oxidation method for the determination of Particulate Organic Nitrogen collected on filters
    Limnology and Oceanography, 1991
    Co-Authors: Patrick Raimbault, Gerd Slawyk
    Abstract:

    A wet-oxidation method with peroxydisulfate digestion at 120°C is presented for routine analysis of Particulate Organic N (PON) collected on glass-fiber filters. The technique was adapted from a previous procedure for oxidizing total N in seawater to NO3− . Comparisons with PON determinations by dry combustion at 800°C indicated high efficiency of the procedure, giving 100% recovery of N with cell cultures and natural seawater samples. Neutralizing buffer and pH adjustment proved to be necessary but were simplified by using a Technicon AutoAnalyzer system. The method was applied to follow NO3−assimilation by phytoplankton cultures and revealed excretion of N compounds by the cells at the end of the exponential phase of growth. The sensitivity of the method makes it possible to filter smaller quantities of seawater than needed for the combustion method (by 1–2 orders of magnitude) and can easily be adapted to shipboard use.

Gerd Slawyk - One of the best experts on this subject based on the ideXlab platform.

  • a semiautomatic wet oxidation method for the determination of Particulate Organic Nitrogen collected on filters
    Limnology and Oceanography, 1991
    Co-Authors: Patrick Raimbault, Gerd Slawyk
    Abstract:

    A wet-oxidation method with peroxydisulfate digestion at 120°C is presented for routine analysis of Particulate Organic N (PON) collected on glass-fiber filters. The technique was adapted from a previous procedure for oxidizing total N in seawater to NO3− . Comparisons with PON determinations by dry combustion at 800°C indicated high efficiency of the procedure, giving 100% recovery of N with cell cultures and natural seawater samples. Neutralizing buffer and pH adjustment proved to be necessary but were simplified by using a Technicon AutoAnalyzer system. The method was applied to follow NO3−assimilation by phytoplankton cultures and revealed excretion of N compounds by the cells at the end of the exponential phase of growth. The sensitivity of the method makes it possible to filter smaller quantities of seawater than needed for the combustion method (by 1–2 orders of magnitude) and can easily be adapted to shipboard use.

  • A semiautomatic, wet‐oxidation method for the determination of Particulate Organic Nitrogen collected on filters
    Limnology and Oceanography, 1991
    Co-Authors: Patrick Raimbault, Gerd Slawyk
    Abstract:

    A wet-oxidation method with peroxydisulfate digestion at 120°C is presented for routine analysis of Particulate Organic N (PON) collected on glass-fiber filters. The technique was adapted from a previous procedure for oxidizing total N in seawater to NO3− . Comparisons with PON determinations by dry combustion at 800°C indicated high efficiency of the procedure, giving 100% recovery of N with cell cultures and natural seawater samples. Neutralizing buffer and pH adjustment proved to be necessary but were simplified by using a Technicon AutoAnalyzer system. The method was applied to follow NO3−assimilation by phytoplankton cultures and revealed excretion of N compounds by the cells at the end of the exponential phase of growth. The sensitivity of the method makes it possible to filter smaller quantities of seawater than needed for the combustion method (by 1–2 orders of magnitude) and can easily be adapted to shipboard use.

Patricia A. Wheeler - One of the best experts on this subject based on the ideXlab platform.

  • Particulate and dissolved Organic Nitrogen in the central and eastern equatorial Pacific
    Deep Sea Research Part I: Oceanographic Research Papers, 1997
    Co-Authors: P. Scott Libby, Patricia A. Wheeler
    Abstract:

    Abstract A wet persulfate oxidation was used to measure Particulate and dissolved Organic Nitrogen (DON) along four transects in the central and eastern equatorial Pacific. Particulate Organic Nitrogen (PON) collected on glass fiber filters ranged from 0.4 to 1.6 μM in the upper 40 m and accounted for about 10% of total Organic Nitrogen (TON). PON collected on 0.2 μm membrane filters was 60% higher than PON collected on glass fiber filters. Most of the Organic Nitrogen was present as DON. DON was lowest at the equator and increased to maximum values in the upper 40 m within 2–5° north and south of the equator. The spatial distribution of TON suggests that it is biologically produced. Meridional export of TON away from the equator could account for 37–75% of nitrate assimilation. The production of DON in the upwelling system of the equatorial Pacific appears to be a major part of the Nitrogen cycle.

  • A wet-oxidation method for determination of Particulate Organic Nitrogen on glass fiber and 0.2 μm membrane filters
    Marine Chemistry, 1994
    Co-Authors: P. Scott Libby, Patricia A. Wheeler
    Abstract:

    Abstract A persulfate wet-oxidation method is presented for determining Particulate Organic Nitrogen (PON) on 0.2 μm membrane filters. We evaluated the suitability of 6 types of membrane filters on the basis of filter blanks, chemical interference and adsorption characteristics. Concurrent comparisons were made using the bicinchoninic acid (BCA) protein assay. The 0.2 μm TF-200 teflon filters had low background N, no chemical interference with either assay, low N adsorption and a higher trapping efficiency than glass fiber filters (Whatman GF/F). A 20–90% increase in PON estimates for water off the coast of Oregon was found using 0.2 μm TF-200 filters compared with GF/F filters. Our results indicate that submicron PON may be a significant component of total N in seawater.

P. Scott Libby - One of the best experts on this subject based on the ideXlab platform.

  • Particulate and dissolved Organic Nitrogen in the central and eastern equatorial Pacific
    Deep Sea Research Part I: Oceanographic Research Papers, 1997
    Co-Authors: P. Scott Libby, Patricia A. Wheeler
    Abstract:

    Abstract A wet persulfate oxidation was used to measure Particulate and dissolved Organic Nitrogen (DON) along four transects in the central and eastern equatorial Pacific. Particulate Organic Nitrogen (PON) collected on glass fiber filters ranged from 0.4 to 1.6 μM in the upper 40 m and accounted for about 10% of total Organic Nitrogen (TON). PON collected on 0.2 μm membrane filters was 60% higher than PON collected on glass fiber filters. Most of the Organic Nitrogen was present as DON. DON was lowest at the equator and increased to maximum values in the upper 40 m within 2–5° north and south of the equator. The spatial distribution of TON suggests that it is biologically produced. Meridional export of TON away from the equator could account for 37–75% of nitrate assimilation. The production of DON in the upwelling system of the equatorial Pacific appears to be a major part of the Nitrogen cycle.

  • A wet-oxidation method for determination of Particulate Organic Nitrogen on glass fiber and 0.2 μm membrane filters
    Marine Chemistry, 1994
    Co-Authors: P. Scott Libby, Patricia A. Wheeler
    Abstract:

    Abstract A persulfate wet-oxidation method is presented for determining Particulate Organic Nitrogen (PON) on 0.2 μm membrane filters. We evaluated the suitability of 6 types of membrane filters on the basis of filter blanks, chemical interference and adsorption characteristics. Concurrent comparisons were made using the bicinchoninic acid (BCA) protein assay. The 0.2 μm TF-200 teflon filters had low background N, no chemical interference with either assay, low N adsorption and a higher trapping efficiency than glass fiber filters (Whatman GF/F). A 20–90% increase in PON estimates for water off the coast of Oregon was found using 0.2 μm TF-200 filters compared with GF/F filters. Our results indicate that submicron PON may be a significant component of total N in seawater.

Bilal Boudjellal - One of the best experts on this subject based on the ideXlab platform.

  • Simultaneous determination of Particulate Organic carbon, Nitrogen and phosphorus collected on filters, using a semi-automatic wet-oxidation method
    Marine Ecology Progress Series, 1999
    Co-Authors: Patrick Raimbault, W Pouvesle, Frédéric Diaz, Bilal Boudjellal
    Abstract:

    A wet-oxidation method is presented for determining simultaneously Particulate Organic carbon (POC), Particulate Organic Nitrogen (PON) and Particulate Organic phosphorus (POP) collected on filters. Conversion of POC, PON and POP to inOrganic products, carbon dioxide, nitrate+nitrite and soluble reactive phosphate respectively, is performed by a persulfate wet-oxidation in slight alkaline condition. After oxidation, inOrganic products are dissolved in the digestion mixture and concentrations are measured automatically by colorimetry using a 3 channel Technicon AutoAnalyzer(R). Concurrent comparisons were made with dry combustion at 950 degrees C for POC and PON (CHN analysis) and with former wet-oxidation procedure for POP. Results indicated high efficiency to oxidize natural suspended Particulate matter from sea- and freshwater as well as phytoplankton cultures and sinking particles collected by sediment traps. This method also exhibits good reliability and precision in comparison with former procedures and is highly suitable for routine analysis and especially appropriate for shipboard work.