Does di or tri moly matter if you are looking at ICP results in a typical VOA / UOA ?
My understanding is that the plasma atomises the sample completely, and then measures the signal produced by the moly atoms. More moly atoms produce a stronger signal. It doesn't matter if the signal comes from volume x of di-moly or volume y of tri-moly, as inside the plasma they are all just lone moly atoms.
Sure when you are using moly add by volume in a formulation, tri is better than di because it contains more moly atoms in the organometallic compound, but inside the plasma you are just counting moly atoms and you don't care how they get there. More moly is better and all moly atoms are the same in a ICP.
From BITOG Article by David Newton
Quote
Used Oil Analysis .........The spectral analysis is done in a Leeman Labs ICP machine."ICP" refers to "inductively coupled plasma" and is the preferred method.....essentially, radio frequency waves are used to excite the atoms of argon gas to a state of plasma at 10,000 deg F. The sample mixture is then introduced into the plasma, and the elements burn completely with energy signatures unique to each element.