In order to evaluate the data obtained by atomic emission spectrometric analysis after ultrasonic extraction, destructive analysis of some certified rock samples employing ultrasonic waves was applied to two elements, Na and K, and the recovery rates were defined. The recovery ratio as K1 = CULM/CCRM was defined for the ultrasonic leaching method (CULM) and the certified reference materials (CRMs). Another recovery ratio, K2 was also defined from the results of the conventional dissolution method (CCDM), that is K2, CULM/CCDM. The accuracy and precision of the method were comparable with those of the conventional methods. The obtained recoveries were between 90.0 % < K1,Na < 106.1 and 90.0 % < K2,Na < 103.0 % for Na and 92.3 % < K1,K < 103.2 and 92.3% < K2,K < 104.5% for K. It was shown that ultrasonic extraction can be effectively used for analytical sample preparation purposes.