Flow Tube Kinetics Investigation of the Mechanism of Detection in the Sulfur Chemiluminescence Detector

Abstract

Rate constants and their temperature dependencies were measured for the chemiluminescent reaction of ozone with the flame and furnace effluents of two commercially available sulfur detectors, the Sulfur Chemiluminescence detector (registered trademark of Sievers Instruments, Inc.) and the Chemiluminescent Sulfur Detector (registered trademark of Antek Instruments, Inc.). The absolute rate constants and activation energies agreed within experimental error with the well-established values for the SO + O(3) reaction in all detector configurations. When ozone was present in the reaction zone, the reaction of the furnace effluent with NO(2) also was in good agreement with the rate constant for the SO + NO(2) reaction. However, when ozone was not present in the reaction zone, little or no reaction occurred with NO(2). These results imply that an unknown sulfur species, X, is formed in the combustion zone and/or transfer line of the instrument and converted to SO upon reaction with ozone in the chemiluminescence detection cell. Based on our experimental results and known reaction rate constants, we can eliminate S(2), S(2)O, SO(2), S(2)O(2), HS, HSO, HSO(2), HOSO(2), and H(2)S as X. We hypothesize that X is S(3) formed in the association reaction of S atoms with S(2) within the transfer line.

Time‐of‐flight mass spectrometry for time‐resolved measurements: Some developments and applications

“…At the pressure of these experiments—1.3 Torr—there is a pressure gradient that was not corrected for but at most will lead to an increase in the values by less than 10%. The bimolecular rate coefficient for reaction (R1) is in good agreement with the recommended literature value ( k 1 = (1.4 ± 0.1) × 10 −11 cm 3 molecule −1 s −1 ) 19, and work from other researchers 8,20–25 (see Table I) and our previous measured value using a smaller range and only four NO 2 concentrations 8 ( k 1 = (1.52 ± 0.16) × 10 −11 cm 3 molecule −1 s −1 ). The good agreement demonstrates that pseudo–first‐order rate coefficients above 1000 s −1 can be reliably obtained.…”

Encapsulation and convex‐face thiozonolysis of triatomic sulfur (S3) with carbon nanotubes

“…In this paper, our goal was to compute various carbon nanotubethiozone combinations for the inclusion of thiozone (S 3 ) into a hollow nanotube space to rationalize when 1,2,3-thiozonide formation can take place and to examine the thiozonolysis mechanism. C 2v symmetric S 3 (1) has been detected by UV-visible, microwave, and infrared spectroscopy [1][2][3][4][5] and has been observed in the atmospheres of Venus and Io because of volcanic activity (Scheme 1). [6][7][8][9] The D 3h form of S 3 (2) has thus far eluded experimental observation.…”

“…The dinaphtho[2,1,8,7-hijk:2′,1′,8′,7′-stuv]ovalene unit used in the B3P86 portion of the ONIOM calculationsTable 2. Calculated properties and energetics of 1 and 2 encapsulated in nanotubes a,b,…”

Designing a reliable leak bio-detection system for natural gas pipelines

“…State-of-the-art detection methods with both specificity and sensitivity for sulfurous molecules, as retrieved by the KB (stage 22) and external bases (stage 23), often require bulky, sophisticated instrumentation such as gas chromatography with flame photometric detector. Gas chromatography with a sulfur chemiluminescence detector has high selectivity and a wide line arrange [125], in which the sulfur-containing substances can be converted into SO 2 in a hydrogen/oxygen furnace and subsequent ozoneinduced chemiluminescence; gas chromatography with atomic emission detection [126] or mass spectrum has also been reported [127], but it has been rejected as an option based on its high cost and highly skilled analysts required. Some of these techniques may additionally require preconcentration of the vapor prior to detection.…”