XRF determination of major & minor elements in nickel ore

In the process of preoxideation Ba(NO3)2 oxidized the low valence of S to the form of sulfate.So compared with other oxidants,it can retain sulphur in borate more efficiently.The RSD of 27.8%sulphur is 0.61%.The accuracy and precision of Ni are greatly improved with Tm as the internal-standard.Using(Li2B4O7:LiBO2=12:22) as the flux,it can accurately measure 15 elements in nickel ore,of which the largest RSD is 9.36%.