ABSTRAKPenelitian penentuan penyebaran konsentrasi logam berat Cd pada sedimen di muara sungai Way Kuala telah dilakukan. Tujuan penelitian ini adalah untuk melihat penyebaran konsentrasi logam berat pada sedimen di muara tersebut. Konsentrasi Cd ditentukan dengan menggunakan spektrofotometer serapan atom (SSA), dengan menggunakan empat validasi metode yaitu batas deteksi, presisi, akurasi, dan linieritas. ABSTRACTThe determination of heavy metal cadmium concentration distributed in Sediment of Way Kuala Estuary Bandar Lampung has been conducted. The aim of the research is to determine the concentration of Cd which is distributed in the sediment. The concentration of Cd was determined using atomic absorption spectrophotometer (AAS). There are four validation methods in these research: limit of detection, precision, accuracy and linearity. The results showed that the concentrations of heavy metal Cd in sediment samples at the upper course, body and downstream in sediments of the Way Kuala Estuary is in the range of 20.73 ± 0.18 to 23.00 ± 0.81 ppm. The result is at above the sediment quality standards (0.65 to 2.49 ppm) which has been established by National Sediment Quality Survey USEPA (2004). Validation method on the determination of heavy metals Cd in sediments showed that the precision has RSD values <5%; Accuracy 80-120%; limit of detection and correlation coefficients for each of the metal Cd are 0.01 and 0.998 respectively.