Results of Simbios Project Round Robin: Part 1, Results of Laboratory-Prepared Standards and Samples
Final rept. Dec 1999-Aug 2001
MARYLAND UNIV CAMBRIDGE CENTER FOR ENVIRONMENTAL AND ESTUARINE STUDIES
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Several laboratories, including but not limited to SIMBIOS and HyCODE investigators, participated in an inter-calibration for HPLC and fluorometer conducted by Horn Point Laboratory of the University of Maryland Center for Environmental Science. The goal of this exercise was to investigate causes of discrepancy between HPLC and fluorometer chlorophyll a values. This exercise was conducted in two phases analysis of laboratory-prepared standards and samples presented in Pant I and analysis of field-collected natural samples presented in Part II. It was found that when methods and instrumentation were not limiting, good reproducibility among laboratories was attained. HPLC values were typically 7-10 lower than fluorometer values. When all analyses were performed at one laboratory with one extraction procedure, results agreed within 19. When laboratories, extraction procedures and analytical methods varied, results agreed within 60. Factors that affected discrepancy included varying extraction procedures between HPLC and fluorometer, inaccurately determining extraction volume, inconsistent HPLC chlorophyll a reporting practices and inaccurate analytical methods.
- Organic Chemistry