Pulsed radiofrequency glow discharge time of flight mass spectrometry for coated glass analysis

Abstract

The analytical potential of radiofrequency pulsed glow discharge time of flight mass spectrometry (rf-PGDToFMS) is investigated for quantitative depth profiling analysis of glasses and thin conductive and nonconductive layers on glasses. PGD in combination with ToFMS can allow the reduction or even removal of spectral interferences by selecting a proper GD pulse interval. Thus, discrimination of potential polyatomic interferences for several analytes (e.g., 28 Si + , 39 K + , 44 Ca + , and 48 Ti + ) was investigated by selecting appropriate time positions along the GD pulse profile. In this paper, the determination of compositional depth profiles of coated glasses was performed by resorting to a multi-matrix calibration procedure. For this purpose, conductive as well as non-conductive certified reference materials were employed to build the analytical calibration curves. Results show that rf-PGD-ToFMS allows us to discriminate the different layers of the samples and the nominal values for element concentrations and layer thicknesses were in agreement with experimental results obtained using the proposed quantification strategy. Moreover, the capability of rf-PGD-ToFMS to provide a full mass spectrum every 33 ms enable the identification of unexpected elements which can be present as contaminants in very thin layers (e.g. Cd, Sn, Te and Sb).

Plasma profiling-time of flight mass spectrometry: considerations to exploit its analytical performance for materials characterization

“…Also, higher sensitivity is obtained at increasing blanking conditions, being the enhancement more pronounced for 184 W + . The fact that filtering most intense ions enables for similar afterglow time domains along the whole m/z range and also similar to those previously obtained with the prototype version (without quadrupole filter) 23 reflects that our previous hypothesis regarding space charge effects and/or saturation issues within the quadrupole seems reasonable.…”

“…Figure 3 collects the pulse profile obtained for 31 P + , 63 Cu + , 90 Zr + , 95 Mo + and 184 W + at 160 Pa, 40 W pulse applied power, 1 ms pulse width and 4 ms period. Similarly to the prototype instrument, 23 the higher the m/z the later the maximum of the afterglow region was obtained (a difference of about 0.13 ms is found between 31 P and 184 W in our experiments). Differently to the prototype version, when using the commercial instrument it can be seen that at increasing m/z ratios the afterglow region becomes narrower and a gap between the end of the plateau and the beginning of the afterglow is obtained.…”

Volatile organic compound analysis by pulsed glow discharge time of flight mass spectrometry as a structural elucidation tool

“…The main components of the PGD‐TOFMS prototype are: (i) a GD bay unit from Horiba (France) consisting of a pulsed radiofrequency (rf) generator (cubo 133–150, Stolberg, Germany), matching box (agilo 1315a‐200, Stolberg, Germany), rf‐connector with a refrigerating disk (cooling the cathode at temperatures lower than 6 °C) and a mounting system with a pneumatic piston to press the cathode against the GD . (ii) the mass spectrometer interface which consisted of a 0.5‐mm orifice diameter sampler and a 1.0‐mm orifice diameter skimmer, with a separation of 7 mm between them, and (iii) an orthogonal time‐of‐flight mass spectrometer (TOFwerk, Switzerland) equipped with a microchannel plate detector …”

Signal Enhancement with Stacked Magnets for High-Resolution Radio Frequency Glow Discharge Mass Spectrometry

“…1 Particularly, the rf-GD-MS has offered efficient depth profile analysis of different materials, such as glass, ceramics and new composite materials, thus widening its applications. [2][3][4][5][6][7][8][9][10][11][12][13] Generally, the principles of rf glow discharge is similar to direct current glow discharge in many respects. However, as an AC potential is applied in an rf-GD process, electrical insulating samples can be effectively sputtered.…”