Many applications require that carbon nanotubes to be functionalized. The most common approach is to form covalent linkages to the oxygen containing functionalities, typically introduced by oxidative purification, that exist on the surface of carbon nanotubes. This motivates the need to control the type and concentration of the oxygen containing groups.

FLOSS (Fluorescent Labeling of Surface Species) enables the selective identification and quantification of oxygen containing functionalities via covalently bound fluorescent dyes. Our FLOSS results show that aldehyde-ketone, carboxylic, and alcohol groups are present on the carbon nanotubes. We will report how the distribution evolves as a function of purification by investigating as-produced (i.e. non-purified) and purified (air/HCl treatment, nitric acid treatment, �) nanotubes. Nanotubes produced by Arc Discharge and High Pressure Carbon Monoxide decomposition (HiPCO) techniques are investigated.