Thermal Gravimetric Analysis question.

[KKAK]

Hello,
how do we determine the metal weight percent of gold nanopartilces that are coated organic thin films by using thermal gravimetric analysis ?

[chem_tr]

I think thermal gravimetric analysis include combustion of organic substances in high temperature like 1500 degrees celsius, and gravimetric determination of the inorganic ones. As nanogold particles are of sufficiently high purity, it would not be difficult to determine them after combustion; to be sure, wash the residue with some polar organic solvents like acetic acid, acetonitrile, dimethyl formamide, then water, and dry the gold bulk again.

To do the gravimetric analysis, you will need to find an appropriate reactant for gold (I think gold is in elemental state here). So, it is likely that you can directly weigh the gold particles, or dissolving them with Aqua Regia (3HCl+1HNO3) and finally reacting with, say, pyrophosphate.