1 / 6

SeaHARRE-3 : the third SeaWiFS HPLC Analysis Round Robin Exercise

SeaHARRE-3 : the third SeaWiFS HPLC Analysis Round Robin Exercise. Scientific Objectives. History 2 previous SeaHARRE exercises, coordinated by S. Hooker (NASA) and LOV: 1999: PROSOPE : mainly mesotrophic; 4 labs (Ref: Hooker et al, 2000; Claustre et al. 2003)

ppamela
Télécharger la présentation

SeaHARRE-3 : the third SeaWiFS HPLC Analysis Round Robin Exercise

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SeaHARRE-3 : the third SeaWiFS HPLC Analysis Round Robin Exercise Scientific Objectives History 2 previous SeaHARRE exercises, coordinated by S. Hooker (NASA) and LOV: 1999: PROSOPE: mainly mesotrophic; 4 labs (Ref: Hooker et al, 2000; Claustre et al. 2003) 2002: BENCAL: mainly eutrophic waters; 8 labs. Agreement between labs: 7% for TChla; 21% for other pigments. “Well within the primary 35% accuracy objective for remote sensing validation purposes” SeaHARRE-3 • Application to extremely low Chlorophyll a concentrations • All participating labs are working on improvement of different methodologies and instrumentation for lower detection limits, better resolution (>1) and higher precision (99%). • 8 Participating labs • Organisers: S. Hooker, H. Claustre, L. Van Heukelem, J. Ras

  2. Methods and measurements to be made Sampling: • Water will be collected at 24 sites and at various depths and trophic conditions. • For oligotrophic and mesotrophic waters: in situ pump with 293 mm diameter GF/F filter. • CSIRO (L. Clementson) is building a punch for cutting out more than 60 replicates from a single filter. • For eutrophic waters (and for regular pigment sampling): 24 post filtration system; positive pressure (to be built). • On board filtration will require thorough mixing of water to maintain homogeneity. Measurements: • HPLC measurements by 8 different labs. Each lab receives 24 batches of 3 replicates. • Other tests will be carried out on remaining replicates

  3. Sampling Water volumes: • For in situ sampling (in collaboration with the IAEA team): • Usually 1h pumping of about 800 L is equivalent to about 6 L on a 25 mm GF/F filter. • For on board filtering (also concerns regular pigment sampling) • Water volume is variable according to Chlorophyll a concentration. First, this will be determined by Turner Fluorimetry (P. Raimbault) providing an estimate of the volume of water to filter for pigments. • A whole CTD cast will be required to collect 24 replicates (long stations only). • Limits of detection of the HPLC method are being improved: maximum volume may vary between 2.8 and 5.6 L per sample in oligotrophic conditions. Minimum volume can reach 0.25 L in eutrophic waters. Technical requirements: • Enough time for in situ pumping (about 1 hour) • Safe transport of samples to their various destinations (Europe, North America, South Africa, Australia). Any ideas?

  4. Regular sampling for phytoplankton pigments • 2 CTD casts per day (up to 12 depths): 1 in the morning, 1 at midday. (In all cases the midday cast must be maintained). • A surface sample will be taken every time in situ optical measurements will be made (Pump? Bucket?). • Necessary water volume per sample: as mentioned before, this depends on result of the Turner fluorimetry measurement. ☼

  5. Participating labs • Laboratoire d’Océanographie de Villefranche – H. Claustre, J. Ras • Horn Point Laboratory (USA)– L. Van Heukelem • Marine Coastal Management (South Africa) – Ray Barlow • CHORS (USA) – Chuck Trees • University of Hawaii (USA) - R. Bidigare • JRC (Italy) – J.F. Berthon • CSIRO (Australia) – L. Clementson • ?

  6. GF/F filter after filtration Variation coefficient of replicates: 4 to 7.6% In situ pump

More Related