TY - JOUR TI - Isolasi, Karakterisasi, dan Penetapan Kadar Flavonoid dari Alga Merah (Eucheuma cottonii) menggunakan Teknik Kromatografi dan Spektrofotometri UV-Vis PY - %2026/%07/%23 Y2 - %2026/%10/%20 JF - Jurnal Medical Laboratory JA - MedLab VL - 5 IS - 2 SE - Articles DO - 10.57213/medlab.v5i2.586 UR - https://doi.org/10.57213/medlab.v5i2.586 SP - 77-90 AB - This study aimed to isolate and characterize bioactive compounds from the red algae Eucheuma cottonii using chromatographic techniques. The dried sample was extracted by maceration with 96% ethanol, followed by liquid-liquid fractionation using n-hexane and ethyl acetate. The ethyl acetate fraction was separated by column chromatography employing seven solvent ratio gradients and monitored using thin-layer chromatography (TLC), followed by preparative TLC and two-dimensional TLC for purity evaluation. The extraction yielded 20.72% crude extract. Column chromatography produced 22 fractions, which were grouped into five categories based on color characteristics: clear, orange, light peach, faint light peach, and clear. TLC analysis showed an Rf value of 0.32, indicating satisfactory separation. Preparative TLC produced a single major band, whereas two-dimensional TLC revealed elongated spots, suggesting that the isolate had not yet reached complete purity. The flavonoid content of the red algae sample, as determined by the UV–Vis spectrophotometric method, was 74.65%. These findings demonstrate that column chromatography is effective as an initial separation method for bioactive compounds from Eucheuma cottonii. However, further optimization of the eluent system is required to obtain compounds with higher purity for subsequent characterization. ER -