Determination of Caffeine in Coffee Samples: Teaching Calibration Curve – Part II Gilmara da Silva Rangel , Tayná da Silva Picanço , Rafael Pinheiro Caetano Damasceno , Ana Carla Rangel Rosa , Mario F. C. Santos, Sávio da Silva Berilli , Murilo de Oliveira Souza 83-91 2026-07-01