Hydrogen Sulfide Detection by UV-Assisted Infrared Spectrometry

Abstract

Ultraviolet (UV)-assisted infrared (IR) spectroscopy has been evaluated for its potential usage and feasibility to indirectly detect hydrogen sulfide gas. Hydrogen sulfide (H2S) is a weakly IR-absorbing compound, and its detection by IR methods is further complicated by severe water interferences. However, H2S can readily be converted to sulfur dioxide (SO2), a strong IR absorber, via ultraviolet irradiation. A multipass IR White cell equipped with an internal mercury germicidal UV lamp has been interfaced to a Bomem MB series Fourier transform infrared (FT-IR) spectrometer. The conversion of hydrogen sulfide to sulfur dioxide (SO2) was tested in five matrices: nitrogen, ambient air, moisturized ambient air, dried ambient air, and zero-grade air. The conversion efficiency of H2S to SO2 in nitrogen, containing a negligible amount of oxygen, was approximately 25% and peaked at approximately 6 min of UV irradiation. In ambient air, the conversion efficiency was calculated to be ∼45% and peaked at 35 s of irradiation, while in the dried ambient air the SO2 concentration peaked in 85 s. In ambient air, the generated SO2 was destroyed during its production and was below detection within 90 s of irradiation. In the dried ambient air, the generated SO2 was still detectable at 120 s of irradiation. Moisturized ambient air was investigated to determine the degree of SO2 loss due to reaction with H2O. From these data, it appears that the water molecule and SO2 photolysis contribute only slightly to the SO2 loss. The greatest loss is apparently caused by reactive radicals such as ·OH generated during UV irradiation. Index Headings: FT-IR; UV photolysis; Vapor phase; H2S; SO2; Environmental analysis.

Optical Fiber Chemical Sensor with Sol-Gel Derived Refractive Material as Transducer for High Temperature Gas Sensing in Clean Coal Technology

“…Present state-of-the-art techniques for detecting hydrogen sulfide in gas samples include ion mobility spectroscopy [35], gas chromatography [36,37], ultraviolet (UV) absorption spectrometry [56,57], near infrared (NIR) absorption spectrometry [40,41] and chemiluminescence techniques [58,59]. Gas chromatography and ion mobility spectrometry are very sensitive for hydrogen sulfide detection, and can be used to detect hydrogen sulfide in a gas sample down to ppb level.…”

“…Although direct UV absorption spectrometry has been reported for detecting hydrogen sulfide, it is difficult to use this method for monitoring H 2 S in complex gas samples. A UV assisted IR absorption spectrometric method has been proposed for detecting H 2 S [57]. This is an indirect method, in which H 2 S is first converted to SO 2 through irradiation of the gas sample with a UV light.…”

A Novel Application of Electroactive Polyimide Doped with Gold Nanoparticles: As a Chemiresistor Sensor for Hydrogen Sulfide Gas

“…There were reports on the use of gas chromatography (GC) [22][23][24], infrared spectroscopy (IR) [25], ultraviolet spectroscopy (UV) [26][27][28][29], and fluorometry [30] in H2S determination, but these techniques involved the use of relatively expensive bulky instrumentation, and requirement of tedious sampling preparations. Alternatively, the use of sensors was also a heightened subject of interest due to the many modes of detection that could be explored such as electrochemical [30][31][32], optical [33,34], piezoelectric [35,36], and chemiresistive [37,38].…”

An active core fiber optic sensor for detecting trace H2S at high temperature using a cadmium oxide doped porous silica optical fiber as a transducer

“…Obviously, a technique for continuously detecting/monitoring the concentration of gaseous sulfur species during the fuel gas treatment processes is critical to ensure the quality of the obtained fuel gas for specific power generation system. Present state-of-the-art techniques for detecting trace hydrogen sulfide in gas samples include ion mobility spectroscopy [9], gas chromatography [10], ultraviolet (UV) absorption spectrometry [11], infrared (IR) absorption spectrometry [12] and chemiluminescence techniques [13,14]. Gas chromatography and ion mobility spectrometry are very sensitive for hydrogen sulfide detection, and can be used to detect hydrogen sulfide in a gas sample down to ppb level.…”

“…Although direct UV absorption spectrometry has been reported for detecting hydrogen sulfide, it is difficult to use this method for monitoring H 2 S in complex gas samples. A UV assisted IR absorption spectrometric method has been proposed for detecting H 2 S [12]. This is an indirect method, in which H 2 S is first converted to SO 2 through irradiation of the gas sample with a UV light.…”