1994 Volume 43 Issue 1 Pages 25-29
The optimum conditions for the direct analysis of Cr, Mn, Fe, Ni, Cu and Pb in photresist by microwave-induced plasma mass spectrometry (MIP-MS) have been investigated. Nitrogen gas, an air and an oxygen-nitrogen mixed gas (oxygen gas in a carrier gas) could be sustained for the plasma souce of MIP-MS. However, nitrogen and an air plasma were not appropriate for analyzing trace elements in organic solutions. The nitrogen plasma was not sufficient for resolving organic solvents. Although an air plasma was sufficient for resolving organic solvents, an Ar ion peak appeared as well as its associated compound. Then, an oxygen-nitrogen plasma was used for analyzing trace metals in a photoresist solution. We carried out an examination of the microwave power on the metal ion intensity and MO-/M- ratio. The proposed method was applied to the determination of Cr, Mn, Fe, Ni, Cu and Pb in commercial photoresist solutions. The photoresist solutions were diluted 10 times with 2-ethoxyethly acetate. These samples were introduced to MIP-MS directly, and were analyzed. The analytical results were in good agreement with the values obtained by graphite-furnace AAS. The detection limits (3σ) were 0.01μg/l for Cr, 0.01μg/l for Mn, 0.05μg/l for Fe, 0.06μg/l for Ni, 0.10μg/l for Cu and 0.04 μg/l for Pb.
