Showing papers by "Walter A. Aue published in 1996"
TL;DR: The AFD mechanism is shown to involve oscillatory chemical kinetics, in which the flame front (the inner cone) temporarily enters a few millimeters into the capillary during each cycle, thereby creating the acoustic signal.
Abstract: A novel gas chromatography detector is described that uses acoustic signals from a partly premixed hydrogen-air flame burning on top of a capillary. The device, referred to as the acoustic flame detector (AFD), is based on the measurement of the frequency of acoustic transients generated at the burner under a range of operating conditions. The presence of trace amounts of analyte in the flame was found to increase the frequency of these sonic bursts from the baseline level of ∼100 Hz. The response of the AFD for n-dodecane, measured as the shift in frequency, was determined to be linear over ∼3 orders of magnitude, with a minimum detectable level of about 1-5 ng C/s using the current system. The sensitivity correlates roughly with carbon content, except for certain organometallics (Sn, Mn), which gave substantially enhanced signals. Some tailing was observed but became serious only for particular types of organometallics. The noise of the system was predominantly of the 1/f type. The effects of flow conditions, burner geometry, and flame gas constituents were investigated. The oscillations could be followed by acoustic, visual, electrical, and optical means. The AFD mechanism is shown to involve oscillatory chemical kinetics, in which the flame front (the inner cone) temporarily enters a few millimeters into the capillary during each cycle, thereby creating the acoustic signal.
7 citations
TL;DR: In this article, a flame photometric detector was connected to a 1 8 -m scanning spectrophotometer, and three experiments were carried out that demonstrated the sensitivity and/or the spectral resolution obtainable from reference scans of single peaks.
5 citations
TL;DR: In this paper, an electron capture detector, two channels of a reactive-flow detector, and a flame ionization detector were physically combined to investigate whether correlation (subtraction and conditional access) chromatograms could be obtained from detectors that operated on entirely different principles and used separate, sequentially arranged monitoring chambers.
5 citations
TL;DR: In this paper, a sixteen-component mixture with aroyl amounts ranging over three to five orders of magnitude, all the way down to the femtomole level, was used as a model system to demonstrate the possibility of computer-mediated, compound-specific detection by dual-channel photometry.
4 citations
TL;DR: In this paper, a dual-channel flame photometric detector has been constructed with the first channel offering high light-throughput to a variable-interference-filter wheel, and the second FPD channel is of the conventional type.
4 citations
TL;DR: In this article, a dual-channel correlational chromatography module with a millisecond time constant was constructed to improve the linear selectivity of a chromium vs. a ruthenium compound.
3 citations
TL;DR: In this paper, a rotating, variable-wavelength interference filter was used to acquire spectra from peak or baseline of a dual-channel, high-sensitivity flame photometric detector.
3 citations
TL;DR: A dual-channel aroyl luminescence detector was constructed and used as a demonstration system for quantitating two perfectly co-eluting model analytes (fluorobenzaldehyde isomers) from subtraction chromatograms and formulas were developed that allowed easy calculation of analyte peak size and detection limit in a subtraction Chromatogram from corresponding single-channel data.
2 citations
TL;DR: As the concentration of analyte increases in the flame photometric detector (FPD), its observed noise changes from a predominantly fundamental to a predominantly multiplicative variety, typically in the 10−9 to 10−8 g/s region, with precise position apparently dependent on the nature of the analyte as discussed by the authors.
1 citations
TL;DR: In this paper, a commercial single-channel flame photometric detector was converted to triple-channel operation by inserting a vertical, mirror-finished aluminum wedge into an earlier installed, auxiliary second channel.
1 citations