[en] Tests for chemical stability were carried out on carrier-added "6"8Ge solutions prepared and calibrated in 2007 and 2011 to evaluate the suitability of the specific composition as a potential Standard Reference Material. Massic count rates of the stored solutions were measured using a NaI(Tl) well counter before and after gravimetric transfers. The present activity concentration of the 2007 solution was also measured using live-timed anticoincidence counting (LTAC) and compared to the 2007 calibrated value. The well counter data indicated no change in massic count rate to within uncertainties for either solution. The LTAC measurements gave a difference of −0.49% in the activity concentration 2007 solution over 7 years. However, the uncertainty in the decay correction over that time, due to the uncertainty in the "6"8Ge half-life, accounted for the majority (0.67% out of 0.83%) of the standard uncertainty on the activity concentration. The results indicate that these carrier-added solutions are stable with regard to potential activity losses over several half-lives of "6"8Ge. - Highlights: • Stability of carrier-added solutions of "6"8Ge were studied. • Two solutions, prepared 3 years ago and 7 years ago, were used. • Massic counts rates before and after transfer were measured. • Activity concentration of 7 year-old solution was measured and compared to standard. • No losses were observed in either solution to within measurement uncertainties.