An improved analytical performance of magnetically boosted radiofrequency glow discharge

Abstract

A magnetically boosted radiofrequency glow discharge optical emission spectroscopy (rf-GD-OES) system has been evaluated using an electromagnet setup that allows the application of transverse magnetic fields up to 70 mT. Such a configuration provides a magnetic field that is independent of the sample thickness. In particular, Cu emission lines, with different upper energy levels, are investigated using GD analysis of a pure copper sample. It is observed that their emission signals are significantly increased when applying magnetic field intensities above a threshold value (∼30 mT). Moreover, it is noticed that the GD pressure conditions as well as the upper energy levels of emission lines are the dominant parameters affecting the enhancement factor of the magnetically boosted Cu emission signals. On the other hand, aluminum matrix samples, with different copper mass contents, have been analyzed using the rf-GD-OES system, both in the normal mode and in the magnetically boosted mode. Linear calibration curves are obtained in both cases, but the slope of the calibration curves (sensitivity) is almost an order of magnitude higher when using the magnetic field. Furthermore, background levels and background noise are not affected by the presence of the external magnetic field; therefore, limits of detection are significantly improved.