Glow-Discharge Mass Spectrometry (GDMS)

In Glow-Discharge Mass Spectrometry (GDMS), the sample to be analyzed forms the cathode in a low pressure (~ 100 Pa) gas discharge or plasma. Argon is typically used as the discharge gas. Argon positive ions are accelerated towards the cathode (sample) surface with energies from hundreds to thousands of eV resulting in erosion and atomization of the upper atom layers of the sample. Only the sputtered neutral species are capable of escaping the cathode surface and diffusing into the plasma where they are subsequently ionized. The atomization and ionization processes are thus separated in space and time, which appears to be a keystone for simplified calibration, quantification and the near matrix independence of this technique.

Although the analysis can be more time consuming than in solution based analytical methods, the sensitivity, the ease of calibration, the flexibility and the capability to analyze wide variety of sample forms and matrices is impressive. Additionally, besides bulk element compositions, it is also possible to collect depth profiling information with very high sensitivity. Evans Analytical Group® (EAG) is the industry standard for GDMS analysis, offering the best detection sensitivity along with accurate mass fraction determinations in solids as well as coatings and layers composition identification. No other analytical laboratory can match EAG's depth and breadth of experience and dedication to research and development in the GDMS field. We have the largest number of GDMS instruments worldwide and highly qualified scientists and analysts.

Our scientists and analysts are also adept at understanding our client's needs and designing an analysis to most effectively address all of your concerns and interests. In fact, EAG regularly uses GDMS to help customers across a range of industries with R&D, quality control, and process monitoring and development. We also make sure you have person-to-person service throughout the process, so that you understand the test results and the implications.

Ideal Uses for GDMS Analysis		Relevant Industries for GDMS Analysis
Trace and ultra-trace element determination in high purity metals, alloys, manufactured carbons and graphites, semiconductor materials, various oxides, carbides and ceramics. Depth profiling of flat surfaces for major, minor and trace elements. Identification of unknowns from minute amount of specimen Full element characterization of powders or particulate materials		Sputter targets Aerospace Refractory metals and alloys Rare earth metals and oxides Precious metals High purity materials production
Strengths of GDMS Analysis		Limitations of GDMS Analysis
Full periodic table coverage (except H) Sub-ppb to ppt detection Minimal matrix effects Linear and simple calibration Capability to analyze insulators Depth profiling of coatings and oxide layers		Sample un-homogeneity Volatile samples Not suited for organic materials/polymers

Application Notes