2.6. Microalgae lipid extraction
Ten grams of dried C. vulgaris biomass were placed in a cellulose
thimble and extraction process was performed using Soxhlet
extractor. Four types of solvent were used to compare the extraction
efficiency, such as n-hexane, methanol, ethanol and mixed
methanol–chloroform with volume ratio of 2:1 [28]. A total of
250 mL for each solvent was placed in Soxhlet extractor and heated
at 60–65 C for 24 h. After that, the solvent was evaporated in a rotary
evaporator and the leftover lipid was collected. The residues
(solid material) after evaporation were subjected to repeated
extraction twice using the same solvent. Thereafter, crude microalgae
lipids were measured gravimetrically. All samplings were
performed in triplicate.