Ruthenium (like Os, Ir, and Rh) is practically insoluble in aqua regia. If one were to add chlorate (very carefully!!!), it will dissolve but exceedingly slow. The easiest method is sodium hypochlorite, for it is quickest and cheapest and I use this frequently. You will get ruthenate anion, a blood red solution (take care not to make acidic).
If they are dissolving it in 0.1 M HCl, then they must be adding chlorate or sparging with Cl2 and taking days. It seems a dubious procedure to me.
What is the nature of the catalyst? Is it ruthenium metal deposited on an inert substrate (i.e. Ru0/Al2O3). XRF or EDXS might be a better, if less quantitative solution.