Effect of ultrasonication and grinding on the determination of lipid class content of microalgae harvested on filters.

To ensure complete lipid extraction of algal samples collected on glass fiber filters, one must facilitate the access of extracting solvent to the lipids by using ultrasonication, grinding, or a combination of these two methods. This study examines the effect of these three treatments, in combination with storage time and sampling volumes, on the determination of lipid class composition of the diatom Chaetoceros gracilis. The TAG level was significantly influenced by treatment in relation to either storage time or sampling volume. FFA and other degradation products increased markedly with storage time at the expense of TAG and phospholipids (PL). Finally, sampling volume and storage time interacted in their effects on TAG and PL contents in an inverse manner.