INFLUENCE OF SOLUTION-DEPOSITED ANIONS ON GLOW-DISCHARGE RELATIVE IONYIELDS

When standard addition methods were employed for quantification in glo w discharge mass spectrometry (GDMS), relative ion yields for some, bu t not all, elements were observed to be greater when deposited as a so lution residue than as a corresponding solid of the same composition. The origin of these effects was investigated and determined to result from the deposition of anions present in the solution standards. The e nhancements could be duplicated from a solid by pretreatment with a so lution containing the anion. The mechanism by which the enhancements o ccur is not well understood, but we believe it involves a form of reac tive etching followed by collisional dissociation of the sputtered mol ecular species into metal ions. Preliminary research suggests that it may be possible to compensate for changes in relative ion yield with s olution treatment by employing an appropriate internal reference stand ard, or to match closely the matrices of the sample and standard in su ch a manner that quantification by standard addition is possible.