This note describes a procedure used for quarter samples acquired during sediment traps experiments in coastal waters. The procedure, which basically consists of stirring the sample with a magnetic device and getting aliquots with a syringe, was developed due the need to obtain representative aliquots from the sample to be used in destructive analysis. The replicability, estimated by the subsampled mass to the aliquot volume, showed the method efficiency, presenting a variation coefficient (standard deviation:mean) smaller than 0.1.