Mass-spectrometric multielement analysis of copper and copper-base alloys, with electrical detection

Improvement in the analysis of ashes from coal by spark source mass spectrography

“…Irradiation with both thermal and epithermal neutrons can improve the analytical results for up to 44 elements in power plant and standard samples (97,102,103 There are a number of factors which determine the precision and accuracy of an analysis by SSMS. The homogeneity of the sample electrodes is important (28,(173)(174)(175)(176)(177). Care must be taken not only to insure the homogeneity of the sample and sample-graphite mixture, but also the homogeneity of the internal standard in the electrodes if the doping method is used (172,178).…”

“…The shape of the sample electrodes should be consistent (28,38,179,180). The spark parameters (e_.£., repetition rate, pulse length) and spark gap width should be constant (28,35,38,171,173,178,177,(179)(180)(181)(182)(183). These parameters affect the relative elemental ionization efficiency in the spark and the ion charge distribution in the spark plasma (31, 173,178,183).…”

“…These parameters affect the relative elemental ionization efficiency in the spark and the ion charge distribution in the spark plasma (31, 173,178,183). Generally, changes in the gap width have a greater effect than does pulse repetition rate and pulse length (177). Use of the ion intensity ratio of the analyte and internal standard from the same exposure in determining elemental concentrations can minimize the effect of spark variations (36).…”

“…The effect of changes in the gap width and ion charge distribution can be minimized by stabilizing the intensities of the matrix lines (184). The positioning of the spark with respect to the entrance slit should be consistent (28,177). The spark position determines what portion of the inhomogeneous spark plasma is sampled by the mass spectrograph (38,(175)(176)(177)179,180).…”

“…The positioning of the spark with respect to the entrance slit should be consistent (28,177). The spark position determines what portion of the inhomogeneous spark plasma is sampled by the mass spectrograph (38,(175)(176)(177)179,180). Other factors concern variations in the ion current at the monitor (177,185) and the spark discharge with time caused by circuitry instability, aging, and other time related variations (171,184).…”