Determination of Metal−Ligand Stoichiometries for Inorganic Complexes Using Total Reflection X-ray Fluorescence

The methods usually used to determine the ratio metal−ligand in inorganic complexes require a set of solutions with different concentrations for both the ligand and metal. We propose a new method using the total reflection X-ray fluorescence technique, in which the ratio between metal and ligand is determined precisely, easily, and quickly. Experimental results provide evidence that for different chemical complexes, the ligand−metal ratio determined by this technique deviates at most from stoichiometric values by 6%. The technique is restricted usually to elements with Z above 14, and its detection limit is on the order of 10-8 g/g.