Sridara, Tharinee, Saijit Daosukho, Subongkoch Subtaeng, and Weera Suanthaisong. 2024. “Method validation for simultaneous determination of heavy metals (Hg, Cd, As and Pb) at trace concentration levels in kratom leaves”. Bulletin of Applied Sciences 13 (1). Bangkok, Thailand:79-91. https://doi.org/10.60136/bas.v13.2024.1255.