ABSTRACT
An analytical method was proposed to determine the ultra-trace metal elements in high-purity tetramethylammonium hydroxide ( TMAH).A total of 12 kinds of ultra-trace metal elements in 25% ( w/w) high-purity TMAH aqueous solution were directly determined after simple dilution with ultrapure water by inductively coupled plasma tandem mass spectrometry ( ICP-MS/MS ).In MS/MS mode, the spectral interferences were eliminated by the reaction of target ions with O2 or NH3/He (1:9, V/V) in the collision/reaction cell ( CRC ) of the ICP-MS/MS.Cr, Mn, Ni and Mo were determined using the O2 mass shift method.Cd and Pb were analyZed based on the O2 on-mass method.Fe, Co, Cu and Zn were determined using the NH3/He mass shift method.Mg and Al were determined using the NH3/He on-mass.The detection limits for analytes were in the range of 0.3-57.2 ng/L.The spiked recoveries were in range of 92.0%-106.0%, and the relative standard deviations (RSDs) were less than or equal to 4.6%.The procedure was applied for determining ultra-trace metal elements in 25% high-purity TMAH aqueous solution.