Alkali flame ionization detector having cap means for changing the gas flow pattern
Abstract
Abstract A hollow flame jet is supported on a base member and surrounded by a cylindrical chimney. The outlet end of a chromatographic column extends into a mixing chamber in the base member where the effluent vapors from the column are mixed with hydrogen. This mixture issues from the flame jet and is burned in the presence of an alkali salt contained in a cup surrounding the tip of the jet. Air to support this combustion enters the chimney at the base of the flame jet. A pair of electrodes positioned near the jet are connected to a fixed voltage power supply and electrometer circuit in order to cause a current to flow in the interelectrode space and to measure this current. The magnitude of this current is proportional to the density of ions in the interelectrode space. Since nitrogen phosphorus-, sulfur-, and chlorine-containing hydrocarbon compounds produce relatively high currents compared with other hydrocarbon compounds, they can be reliably detected and quantified in the effluent stream.
Inventors
- 👤 Charles H Hartmann
Bibliographic Details
Claims Analysis
Total Claims: 4References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-20 | 1975-03-22 | 1975-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-20 | 1979-03-22 | 1979-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-20 | 1983-03-22 | 1983-09-21 | $7700.00 | Window Closed / Lapsed |