Temperature controller for thermal ionization mass spectrometry

Abstract

We describe the use of a simple voltage stabilizer that controls the filament temperature (T(f)) in the ion source of a thermal ionization mass spectrometer. The filament voltage (V(f)) is measured by means of a separate pair of wires connected inside of the ion source in parallel to the wires supplying power. It has been demonstrated that V(f) is directly proportional to T(f) in a wide range of filament temperature. The T(f) value is solely controlled by the reference voltage (V(r)) that can be manually selected from a voltage divider or by means of a computer. Digital signals from the computer in the form of a series of pulses are transmitted opto-electronically and subsequently converted to analog signals. The temperature controller described here was successfully applied for analysis of potassium concentration by the isotope dilution method.

Biomonitoring Studies and Preventing the Formation of Biogenic H2S in the Wierzchowice Underground Gas Storage Facility

“…The isotope ratios (δ 34 S and δ 18 O) were determined by means of a dual inlet and triple collector mass spectrometer on SO 2 and CO 2 gases, respectively. SO 2 was extracted by the method developed in the Lublin laboratory [37][38][39], whereas CO 2 was prepared by the method described by Mizutani [40] and improved by Halas et al [41].…”

“…The reproducibility of both analyses, obtained on the basis of replicated SO 2 extractions, was about 0.16‰. Delta values were normalized to the VCDT and the VSMOW scales by analysis of the NBS-127 standard, for which we accepted δ 34 S = 21.14‰, after Halas and Szaran [37], and δ 18 O = 8.73‰ according to the recent calibration performed vs. VSMOW by Halas et al [41].…”