Abstract
With the development of new carbon materials such as nanotubes, the determination of sample-batch elemental concentrations is essential to promote quality control and ensure reliability of technological applications. Here, we propose an alkaline oxidation (a.k.a. fusion) method as a valuable approach to disintegrate/digest the graphitic structure of carbon nanotubes. This pre-treatment step enables the subsequent reading of the elemental concentrations with routine analytical tools such as inductively coupled plasma optical emission spectroscopy (ICP-OES). The fusion method was validated using a standard nanocarbon, namely the SWCNT-1, which is produced by Canadian National Research Council. Following the carbon matrix disintegration, clear homogeneous solutions were obtained upon dilution of the glass in nitric acid. Three certified elements were probed, namely Co, Ni and Mo, with recoveries attained in the order of 80%. Furthermore, the fused remainders were collected and investigated with Raman spectroscopy, transmission electron microscopy and nuclear magnetic resonance. The results show that the fusion method followed by ICP-OES analysis can be used for the quantification of transition metals. Alongside, there seems to be structural changes in the carbon network that are fairly different from those obtained using classical wet digestion methods.