Aim: to assess the linearity, sensitivity, precision and accuracy of visible spectrophotometric methods to assay the fucoidan content in the water extract of Sargassum aquifolium (Turner) C. Agradh from two different sources.
Methods: Fucoidan was hydrolyzed by sulphuric acid, the fucose residues were converted to form 5-methylfurfural then reacted with cysteine to form fucosecysteine complex that give pale yellow or greenish yellow colour. The operating time was 25-35 minutes, then the absorption was measured in 399.7 nm.
Results: Linearity was in the range of 20-140 ppm with correlation coefficient of 0.9925. The limit of detection and limit of quantitation were 0.49 ppm and 1.48 ppm, respectively. The relative standard deviation was 1.1% and the recovery was in the range of 99.62 – 105.73%. The fucoidan content in the water extract sample from Garut and Banten were 16.79% and 12.35%, respectively.
Conclusion: This method met the validation requirements that were linearity, precision and accuracy. There were significant differences in fucoidan content in the Sargassum aquifolium (Turner) C. Agradh extract from two different sources.