Communication. Selective removal of plasma matrix ions in plasma source mass spectrometry

摘要: We report a new method for selective removal of argon ions and other plasma matrix in source MS. The consists sampling the reacting sampled analyte with hydrogen gas. Reactions have been studied three instruments: ion trap (PSIT) mass spectrometer post-skimmer region both conventional ICP second PSIT. In trap, reaction between Ar+ H2 proceeds at nearly collisional rate whereas most atomic is four to five orders magnitude slower. For modest pressures times [10–4 Torr (1 = 133.322 Pa) 10 ms], signal reduced by six magnitude. examined reactions 33 different ions; only which was evident were N+, O+, Cl+, Ar+. decrease occurs sequence fast resulting charge transfer from form low m/z H2+ H3+, are rapidly ejected trap. net effect chemically, not virtue its mass-to-charge ratio only, as resonant ejection methods. ICP-MS experiments time short, limiting about 40-fold preliminary unoptimized experiments. However, still selective: simple scattering reduces 45Sc+ 5% reactive loss Production H3+ observed directly experiments, indicating that chemistry consistent discuss methods reduction might be realized ICP-MS, thus possibly allowing greater transmission efficiency space-charge effects.