Anik Eko Novitasari and Nikmatul Fitriyah 2025. Effect of Extraction and Centrifugation on Caffeine Levels in Urine of Robusta Coffee Drinkers Using the Method of Uv-Vis Spectrophotometry. International Journal of Health, Economics, and Social Sciences (IJHESS). 7, 1 (Jan. 2025), 219~225. DOI:https://doi.org/10.56338/ijhess.v7i1.6844.