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Monitoring Rotary Vacuum Pump Oil Degradation by Using Field Desorption (FD)-TOFMS and Group-type Analysis Software

Field Desorption (FD) is a technique that ionizes analytes by electron tunneling from the analyte molecules to a solid surface (emitter) in a high electric field. The sample is applied directly onto the emitter and heated by applying an electric current through the emitter for desorption and ionization. FD has been used for the analysis of nonvolatile compounds, synthetic polymers, etc., as a soft ionization method to produce molecular ions with little or no fragmentations. As a result, the average molecular weight of a sample can be calculated directly from the masses (or “m/z”) and intensities for all of the ions observed in the FD mass spectrum. Furthermore, by applying group-type analysis, the components can be classified into types based on their functional groups and/or unsaturations. Average molecular weight, polydispersity index, or relative abundance of each type can also be obtained. In this work, new and used rotary vacuum pump (RP hereafter) oils were analyzed by FD. Afterwards, the change in their compositions was determined by performing group-type analysis on the resulting mass spectra.

Analysis of Additives in Plastic by Thermal Desorption (TD)

Among the various methods used for characterizing plastics, pyrolysis (Py) GC/MS and thermal desorption (TD) GC/MS are widely used for both qualitative and quantitative analyses. These are simple techniques that provide detailed information about the samples. In this application note, we report the analysis of additives in plastic by using a thermal desorption system and a JEOL JMS-T100GCV "AccuTOF GCv" GC-TOFMS. Identification of the analytes was accomplished by library search and accurate mass measurement. Additionally, isotope cluster pattern matching was performed using the "Mass Spec Tools™" software to help identify an unknown compound that was present in the sample.

Other Resources

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Corona - Glow Discharge (DART Ion Source)

February 22, 2020