Extraction of benthic microalgal pigments for HPLC analyses

Studies of microphytobenthic communities often require the use of HPLC pigment analysis. The first step of such chromatographic analyses consists of extracting pigments. Three methodological points relative to sedimentary pigment extraction for subsequent HPLC analyses were examined using sediment samples from a mudflat. We studied effects of both sample freeze-drying prior to extraction, and 2 extraction solvents (100% acetone and buffered methanol). We also examined the influence of extraction time on pigment recovery. Freeze-drying significantly improved pigment extraction from mud samples. Acetone yielded significantly better recoveries of pheopigments, but (in freeze-dried sediment) acetone and buffered methanol did not differ significantly in their extraction of chi a or carotenoids. Longtime extraction (up to 24 h) improved recovery of chl a, but not other pigments.