SARI, Melati Ireng; PRABU PUTRI, Zeolita; ANGGUN SARI, Debi; INDAH LESTARI, Dwi. Comparative Study of The Effect of Water Sample Preservation Variations and Spectrophotometer Types on Chemical Oxygen Demand (COD) Testing Results. International Journal of Science and Environment (IJSE), [S. l.], v. 6, n. 1, p. 698–704, 2026. DOI: 10.51601/ijse.v6i1.393. Disponível em: https://ijsenet.com/index.php/IJSE/article/view/393. Acesso em: 25 feb. 2026.