Pushing the relative mass accuracy limit of ISOLTRAP on exotic nuclei below 10 ppb

The Penning trap mass spectrometer ISOLTRAP plays a leading role in mass spectrometry of short-lived nuclides. The recent installation of a radio-frequency quadrupole trap and a carbon cluster ion source allowed for the first time mass measurements on exotic nuclei with a relative uncertainty of deltam/m approximately equals 1 multiplied by 10**-**8. The status of ISOLTRAP mass spectrometry and recent highlights are presented