Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
Browse
2 results
Search Results
Article Citation - WoS: 24Fiber Optic Sensors Using Novel Substrates for Hydrogen Sulfide Determination by Solid Surface Fluorescence(Elsevier Ltd., 2000) Eroğlu, Ahmet Emin; Volkan, Mürvet; Ataman, O. YavuzTwo different fiber optic sensors were developed for the determination of hydrogen sulfide at ppb concentration levels; a probe-type fiber optic sensor coated with polyethylene oxide containing 0.5 M CdCl2 and a fiber optic sensor utilizing 0.5 M CdCl2-pretreated filter paper as solid substrate. In the first type, CdCl2–polyethyleneoxide (PEO) mixture was coated onto the tip of a fiber optic probe and the probe was exposed to H2S. The methodology is based on the measurement of CdS fluorescence on the surface. Detection limit (3s) of the PEO-coated fiber optic system was 36.0 ppb for H2S and precision at the 0.552 ppm level was 29% R.S.D. For the fiber optic system utilizing CdCl2-pretreated filter paper, two different configurations were devised and evaluated; a bifurcated fiber optic sensor and a single fiber optic sensor. Similar figures were obtained with these two systems; the detection limit (3s) was 4.0 ppb for the bifurcated fiber optic sensor and 4.3 ppb for the single fiber optic sensor, and both sensors had linear responses in the range 0.032–1.0 ppm. Their precisions at 0.299 ppm level were also very similar, 10 and 11% R.S.D., respectively, for the bifurcated and single fiber systems. In addition to the fiber optic sensors developed, various surfactants (sodiumdodecylsulfate (SDS), Aerosol OT, Aerosol A102, Aerosol 501), some cellulosic substances (sodium carboxymethylcellulose (CMC), ethylcellulose, hydroxypropylmethylcellulose, ethylhydroxyethylcellulose, α-cellulose) and several water-soluble polymers (polyacrylicacid polyethleneoxide (PEO), polyvinylalcohol (PVA)) were dissolved in proper solvents and after mixing with 0.5 M CdCl2, were spread over glass slides. These novel solid substrates were exposed to H2S and fluorescence signal on the surfaces of the glass slides was measured with a luminescence spectrometer. The new substrates were shown to be good alternatives to filter paper for the determination of H2S by room temperature solid surface fluorescence spectrometry.Article Citation - WoS: 9A novel sorbent tube for ambient hydrogen sulfide determination(Elsevier Ltd., 1998) Eroğlu, Ahmet Emin; Volkan, Mürvet; Eroğlu, Tijen; Ataman, O. Yavuz; Mark, Harry B.A novel tubular device has been developed for hydrogen sulfide determination in air. Several substrates such as commercial silica gel and alumina TLC plates, silica gel powder, alumina, CaSO4, CaCO3, BaSO4, MgO, chalk, α-cellulose and ethyl cellulose were tested as solid substrates. 30–70-mesh silica gel was finally employed in glass tubes of 4.0 mm internal diameter. Silica gel is treated with 0.5 M aqueous CdCl2 solution, dried, filled into the glass tube and sample gas is passed through the device using nitrogen as the carrier gas where 70% relative humidity is employed. The analyte reacts with the solid substrate to form a luminescent spot whose length in the tube is measured and correlated to concentration. The flow rate was 68 ml min−1. The analytical system is linear in the range of 0.2–1.3 ppm H2S for the specified conditions. The prepared devices are stable at least for 3 months prior to sampling; and after sampling, the luminescing spot is stable also at least for 3 months.