Influence of solution-deposited anions on glow discharge relative ion yields

When standard addition methods were employed for quantification in glow discharge mass spectrometry (GDMS), relative ion yields for some, but not all, elements were observed to be greater when deposited as a solution 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 enhancements could be duplicated from a solid by pretreatment with a solution containing the anion. The mechanism by which the enhancements occur is not well understood, but we believe it involves a form of reactive etching followed by collisional dissociation of the sputtered molecular species into metal ions. Preliminary research suggests that it may be possible to compensate for changes in relative ion yield with solution treatment by employing an appropriate internal reference standard, or to match closely the matrices of the sample and standard in such a manner that quantification by standard addition is possible.