New Data Products and Reporting Practices for HPLC Pigments
Laurie
Van Heukelem, HPL-UMCES, laurievh@hpl.umces.edu
(Presenting)
Stanford
B
Hooker, NASA-GSFC, stanford.b.hooker@nasa.gov
(Presenting)
Crystal
Thomas, HPL-UMCES, cthomas@yahoo.com
(Presenting)
HPLC pigment reporting practices for NASA investigators have changed. Effective March 2008, all concentrations will be rounded to three digits (instead of four), pigments not found, or those less than or equal to 0.0005 µg/L will be considered not quantifiable and will be given a limiting concentration of 0.0009999 µg/L, and Chlorophylls c2 and c1 will no longer be individually quantified. Columns for individual pigment concentrations are now classified according to whether the pigment is a primary, secondary, tertiary or ancillary pigment†. Higher-order data products, the pigment sums, ratios and indices will also be reported in columns to the right of individual pigments. These products exhibit lower uncertainties, as made evident in SeaHARRE round robins and it is hoped they will give users of the data more immediate access to trends in the results. Pigments in chromatograms that were un-quantifiable (e.g. the no-detects), are given a concentration of zero when formulating higher order data products. The same should be done if end users of the data wish to formulate additional higher-order products from individual pigments. Graphs of data from NASA investigators illustrate the rationale for making these changes and show the utility of higher-order products.
† Hooker et al. 2005, which is posted at www.hpl.umces.edu/pigments for your convenience
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