Surface enhanced resonance Raman scattering (SERRS) has been applied to investigate defects in purified and carboxylated single-walled carbon nanotubes (SWCNTs). For both samples SERRS spectra with temporal fluctuating peak intensities and positions in the range of 1000-1350 cm(-1) have been observed. A series of peaks in this window coincide with peak positions that have been assigned to arise from Stone-Thrower-Wales and heptagonal-pentagonal intramolecular junction defects on the nanotubes surface. The role of possible amorphous carbon impurities is also discussed. (C) 2012 Elsevier B.V. All rights reserved.