Atomic Absorption Spectra of Europium, Thulium, and Ytterlium Using a Flame as Line Source SIR: Perhaps the major disadvantages in the applic'ition of atomic absorption spectropliotometry have been the expense of acquiring hollow cathode tubes of the indiyidual elements and the relatively lons warm-up times required for them t o reach stability. I n addition, holloly c hthode tubes are not readily available fcr some of the less common elements including many of the rare earths. The reports by Manning and Slavin (6) and Alkemade and Nilatz ( 1 ) that lithium could be determined using a flame as the lithium line source indicated that the same might be possible for some of the rare earths. Preliminary experirne i t s have shown that atomic absorpiion spectra of analytical utility can be observed for europium, thulium, and ytterbium using this method. EXPERIMENTAL
The observations reported below were made with a Bec
