Thimerosal=ethyl mercury and my dentist told me amalgam mercury is ionic mercury(though im not certain of this myself). If you can get to the German company "Heyls" website(cant remember how i did this) and tell them your a doctor or student of pharmacy you can download the scientific monograph for DMPS which is around like 300 pages long and goes into HUGE details comaparing DMSA to DMPS and there effectivenss of chelating a range of metals and a range of different types of mercury.