Absorption cell with fiber optics for concentration measurements in a flowing gas stream

Single optical fiber, position-sensitive detector-based multiwavelength absorbance spectrophotometer

“…A microbore separation of 2,4-dintrophenylhydrazone (DNPH) (Aldrich Chemical Co., Milwaukee, WI) derivatives of aldehydes was included in this study to demonstrate the utility of the multiwavelength PSD-based absorbance detector with flowing liquid systems. The HPLC system consisted of a syringe pump (ISCO, LC-250, Lincoln, NE) coupled to a 0.5-mL injection valve (Rheodyne, 7125, Cotati, CA) and on to a 1 mm X 250 mm, 5 Mm, C18 column (Alltech, Abosbosphere HS, Deerfield, EL) which was connected to the UV-vis flow cell previously described. The eluent used for the reversed-phase separation of the aldehyde-DNPH derivatives consisted of 80% methanol (EM Science, Omnisolv, Cherry Hill, NJ) and 20% water (EM Science, Omnisolv, Cherry Hill, NJ) at a volumetric flow rate of 50 µ ,/ and a typical column pressure drop of 1580 psi.…”

“…Remote absorbance measurements are also of interest, where fiber optics are utilized (5)(6)(7)(8)(9)(10)(11)(12)(13). Remote absorbance sensing is important in process analysis (5, 7, 9, 12, 13), in bioanalytical monitoring (6), and in field-portable or applied instruments (11).…”

“…Solarization must be evaluated for a given fiber optic based absorbance spectrophotometer. Since qualitative results are generally reported (5), more thorough investigation is warranted.…”

Atomic line molecular analysis for multicomponent determinations in the gas phase

“…Fuwa and Vallee detected S02 by using flame absorption at 207 nm (19). Saturday measured UF6 and PuF6 by using fiber optics (20). These workers achieved sensitive detection (e.g., 13 ppm for PuFe) but had to develop methods to confirm that the analyte gas was the only species absorbing at the wavelength used for the analysis.…”