Development and Evaluation of a Glow Discharge Microwave-Induced-Plasma Tandem Source for Time-of-Flight Mass Spectrometry

Abstract

In this work, a new glow discharge, microwave-induced-plasma (GDMIP), tandem ion source was developed, characterized, and used in conjunction with time-of-flight mass spectrometry. This tandem source was designed to be simple and compact The GD and the MIP unit are independent and demountable, providing flexibility in tuning and operating. The microwave plasma can be formed with very low power (a few watts) and overlapped with the glow discharge. The discharge current increased with the addition of microwave discharge when the GD was operated in constant-voltage mode, and the amplitude of the current increase was found to be related to microwave power, discharge pressure, and sampling distance. With the addition of microwave discharge, significant signal enhancement was achieved under a discharge pressure of 2.0 Torr and a discharge voltage of 500 V with 2.0-mm sampling distance. Enhanced factors of analyte signals ranging from approximately 1 to nearly 10 could be obtained with MIP boosting, while no significant change in noise level was observed. This new tandem source provides improved performance in direct solid sample analysis.

Ambient ionization and direct identification of volatile organic compounds with microwave‐induced plasma mass spectrometry

“…MIPI has the advantages of stability, reproducibility, no requirements for solvents and electrodes, relatively high plasma temperature varying from ~100 °C in tail plume to over 1000 °C in the discharge center . The technique has been broadly used in the field of optical emission spectrometry, inorganic mass spectrometry, etc.…”

Atomic Spectrometry Update. Atomic mass spectrometry

“…In the first reported measurement of low levels of 99 Tc by AMS, Fifield et al 79 used high purity aluminium oxide as the bulk material with a known trace amount of 103 Rh added as reference element. The contribution from 99 Ru was quantified by measuring the 101 Ru isotope. In contrast to conventional AMS, in which at least one isotope is measured as a beam current, in the procedure described all three isotopes ( 103 Rh, 101 Ru and 99 Tc) were present in very low concentrations (v10 27 ).…”

The Study of Titanium and Zirconium Ions in Water by MPT-LTQ Mass Spectrometry in Negative Mode

“…The power dissipation of MPT is usually low, less than 200 W, thus it is promising for use in the coming portable analysis fields. The plasma technique possesses strong excitation ability and good universality, hence MPT has been used widely as a powerful light source in spectrometric instruments [ 21 , 22 , 23 , 24 , 25 , 26 ], and even then been applied in the direct analysis of solid samples [ 27 ]. Our previous studies have showed that the MPT, as an ambient ion source, coupled with a linear ion trap mass spectrometer, can be a potential analytical tool in various fields, especially in the analysis of metal elements [ 17 , 18 , 19 , 20 , 28 ].…”