In the course of our investigation1,2,3of metal pollutants in ambient air using flameless atomic absorption spectroscopy, we have encountered difficulties in obtaining carbon rods which were sufficiently free of metallic impurities. Since carbon is employed as a means of atomization in several non-flame cells described in the literature and available commercially, we felt that it is important to note that none of the carbon rods that we have studied were free of metallic impurities. Various grades of spectroscopic carbon electrodes from several manufacturers have been examined. Some brands were significantly purer than others, and the extent of impurity has been found to vary from lot to lot from the same manufacturer. We have not attempted to determine the concentration levels of the various impurities.