JET-ENHANCED SPUTTERING CELL AS AN ION-SOURCE FOR MASS-SPECTROMETRY

A Jet-enhanced sputtering cell, the Atomsource from Analyte Corp., Is Interfaced to a VG PlasmaQuad inductively coupled plasma mass spectrometer replacing the inductively coupled plasma. The sputtering cell allows for the direct analysis of flat metal samples by clamping them over a round opening, surrounded by an O-rlng, in one side of the cell. Six streams of argon, accelerated to high speed by passage through small nozzles and Ionized by the current, strike the sample in a hexagonal pattern, sputtering out atoms and rapidly eroding the sample surface. Ions produced by the electrical discharge enter the mass spectrometer through a modified sampling “cone” or flange. The Influences of pressure, current, anode-to-sampling flange voltage, sampling distance, and sampling flange orifice diameter are optimized to obtain Improved performance for analytical applications. Because air and water are not present during sample atomizatlon (except as surface contaminants), there are reduced interferences from ArO, ArC, and ArN relative to inductively coupled plasma mass spectrometry (ICP-MS). Detection limits are generally comparable to those obtained with the ICP-MS. Differences In interferences improve the detection limits in some cases, such as B and some transition elements in Zircaloy. © 1990, American Chemical Society. All rights reserved.