iCONVERT: An Integrated Device for the UV-Assisted Determination of H2S via Mid-Infrared Gas Sensors

Author(s)

da Silveira Petruci, Joao Flavio ^{[1, 2]} ; Cardoso, Arnaldo Alves ^[2] ; Wilk, Andreas ^[1] ; Kokoric, Vjekoslav ^[1] ; Mizaikoff, Boris ^[1]

Affiliation

^[1] Univ Ulm, Inst Analyt & Bioanalyt Chem, D-89081 Ulm - Germany

^[2] Sao Paulo State Univ, Dept Analyt Chem, UNESP, BR-14800970 Araraquara, SP - Brazil

• Document type: Journal article
• Source: Analytical Chemistry; v. 87, n. 19, p. 9580-9583, OCT 6 2015.
• Web of Science Citations: 14

Abstract

In this technical note, we describe an integrated device platform for performing in-flow gaseous conversion reactions based on ultraviolet (UV) irradiation. The system combines, using the same footprint, an integrated UV-conversion device (iCONVERT), a preconcentrator unit (iPRECON), and a new generation of mid-infrared (MIR) gas cell simultaneously serving as a photon conduit, i.e., so-called substrate-integrated hollow waveguide (iHWG) optically coupled to a compact Fourier transform-infrared (FT-IR) spectrometer. The iCONVERT is assembled from two blocks of aluminum (dimensions, 75 mm x SO mm x 40 mm; L x W x D) containing 4 miniaturized UV-lamps (47mm x 6 mm X 47 mm each). For the present study, the iPRECON-iCONVERT-iHWG sensing platform has specifically been tailored to the determination of H2S in gaseous samples. Thereby, the quantitative UV-assisted conversion of the rather weak IR-absorber H2S into the more pronouncedly responding SO2 is used for hydrogen sulfide detection. A linear calibration model was established in the range of 7.5 to 100 ppmv achieving a limit of detection at 1.5 ppmv using 10 min of sample preconcentration (onto Molecular Sieve SA) at a flow rate of 200 mL min(-1). When compared to a conventional UV-conversion system, the iCONVERT revealed similar performance. Considering the potential for system miniaturization using, e.g., dedicated quantum cascade lasers (QCL) in lieu of the FT-IR spectrometer, the developed sensing platform may be further evolved into a hand-held device. (AU)

• FAPESP's process: 14/23974-3 - Development of gas sensors based on substrate-integrated hollow waveguides and infrared spectroscopy for environmental targets monitoring
• Grantee: João Flávio da Silveira Petruci
• Support Opportunities: Scholarships abroad - Research Internship - Post-doctor