A comparative study on the estimation of extracted pigments from some algae using different solvents

Four different solvents were used to study their efficiency on pigments extraction from three different algal species of Chlorella vulgaris, Spirulina platensis and Nannochloropsis oculata. Dimethylsulfoxide, acetone, ethanol and methanol were used in the extraction process. The experiment was performed in both of fresh and oven dried algal samples. Chlorophylls a, b, total chlorophyll and total carotene concentrations were determined spectrophotometrically and by HPLC technique. The spectrophotometric method revealed that, dimethylsulfoxide surpasses all other used solvents in all species and all pigments in fresh samples except for chlorophyll a of N. oculata, whereas acetone was more effective than the others in fresh and dry sample. For the dried sample of C. vulgaris, methanol gave the maximum extractability with chlorophyll a while chlorophyll b and total chlorophyll were found be maximum in dimethylsulfoxide solvent. In Spirulina, methanol represented the maximum chlorophyll a and total chlorophyll for the dried samples. Total carotene was found to be higher in ethanol solvent with both C. vulgaris and N. oculata but dimethylsulfoxide surpasses the other solvents with S. platensis. HPLC results emphasized that, acetone surpasses all other used solvent in fresh samples and methanol was ideal solvent in dry samples of C. vulgaris. Dimethylsulfoxide represented the maximum chlorophyll a and total carotene with Spirulina in both samples. Methanol was the best solvent for extraction of all pigments with N. oculata except with A¢-carotene of dry sample, ethanol was the best solvent.