Mass measurements of 49,50 Sc, 70 As, 73 Br and 196 Hg produced at CERN's radioactive beam facility ISOLDE are presented. The measurements were performed using the multi-reflection time-of-flight mass spectrometry and time-of-flight ion-cyclotron-resonance techniques with the ISOLTRAP mass spectrometer. The new results agree well with literature values, improving mass accuracy for all isotopes.