This document specifies methods for characterizing the chemical properties of powders or liquid dispersions containing graphene-related two-dimensional material (GR2M), using a set of suitable measurement techniques. This document covers the determination of elemental composition, oxygen to carbon ratio, trace metal impurities, weight percentage of chemical species and functional groups present, by use of the following techniques: X-ray photoelectron spectroscopy (XPS); thermogravimetric analysis (TGA); inductively coupled plasma mass spectrometry (ICP-MS); Fourier-transform infrared spectroscopy (FTIR). This document covers sample preparation, protocols and data analysis for the different techniques.