Methodology for Quantification of Geosmin and Levels in Rangia Clam (Rangia cuneata)

Authors

  • URAIWAN TANCHOTIKUL,

    1. Authors Tanchotikul and Hsieh are with the Dept. of Food Science, the Louisiana Agricultural Experiment Station, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803. Address inquiries to Dr. Thomas C.-Y. Hsieh.
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  • THOMAS C.-Y. HSIEH

    1. Authors Tanchotikul and Hsieh are with the Dept. of Food Science, the Louisiana Agricultural Experiment Station, Louisiana State Univ. Agricultural Center, Baton Rouge, LA 70803. Address inquiries to Dr. Thomas C.-Y. Hsieh.
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  • Louisiana Agricultural Experiment Station manuscript number 89-21-3594.

  • Supported in part by grants from NOAA Louisiana Sea Grant College Program and Ralph and Kacoo Olinde Aquaculture Research Award to author Hsieh.

  • We thank Dr. Peter Johnsen of USDA-ARS, SRRC for the geosmin standard and Linda Andrews, Warren Mermilliod, and Malcolm Assevado for assistance in clam collection.

ABSTRACT

The concentration of geosmin was determined in freshly dredged and 2-wk relayed rangia clam (Rangia cuneata) samples in different seasons of the year. Vacuum distillation/solvent extraction using an internal standard was followed by multiple-level standard addition gas chromatography/selective ion monitoring mass spectrometry. Most coefficients of variation were lower than 10%. On a dry-weight basis, the geosmin level in dredged clams was highest (343 ng/g) in August and averaged 51.6 ng/g in other months. A 52% reduction of geosmin was found after two week relaying during the period of May-June. However, only 1% reduction of geosmin was observed during February-March.

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