USE OF THE AR-2(-TOOL IN SOLID SAMPLING ELECTROTHERMAL VAPORIZATION INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY() SIGNAL AS A DIAGNOSTIC)

The utility of the Ar-2(+) signal (at mass-to-charge ratio m/z=80) as a diagnostic tool in solid sampling electrothermal vaporization induct ively coupled plasma mass spectrometry (ETV-ICP-MS) is reported, Simul taneous monitoring of the argon dimer signal with the signal(s) of the analyte element(s) indicated that non-spectral interferences, caused by matrix components co-volatilizing with the analyte element(s), can strongly affect the analyte signal profiles in solid sampling ETV-ICP- MS of samples of biological or environmental origin, This observation led to a more profound understanding of why, for a given matrix, the s ignal profiles strongly differ from one element to another, and why, f or a given element, the signal profile is seen to be strongly dependen t on the matrix, These matrix effects were also observed to cause a cu rvature in the sample mass response curves (analyte signal intensity a s a function of sample mass), It is shown that, at least in some insta nces, the use of the Ar-2(+) signal as an internal standard allows (i) this non-linearity to be corrected for and (ii) accurate analysis res ults to be obtained, Finally, it is demonstrated that simultaneous reg istration of the argon dimer and the analyte signal(s) is useful durin g optimization of ashing and vaporization temperatures.