摘要:
A method for identifying analytes of interest by referencing to a retention factor database corresponding to a plurality of identified analytes that is independent of column dimensions and carrier gas type while dependent upon stationary phase type ratio and a relative temperature program. The retention factor database is generated on a reference GC system in which the column head pressure is adjusted to ensure high reproducibility of retention times by locking the column void time and/or the retention time of an identified analyte to a specific value such that accurate retention factors (k) can be calculated in accordance with the formula: ##EQU1## where VT is the void time of the column having a specified stationary phase and phase coating installed in a GC system operating in accordance to a specified temperature program (where time is expressed in units of column void time).
摘要:
The invention provides a method for automated matching of retention times obtained using a known chromatographic method having a defined set of column parameters and operating parameters to the retention times obtained using a new chromatographic method having a new set of column parameters, wherein the retention times of components separated in accordance with the new chromatographic method are matched to the retention times set forth in the known chromatographic methods. A procedure is described to adjust head pressure to compensate for differences in a new versus the original column, carrier gas, and column outlet pressure of the known method.
摘要:
The invention provides a method for developing a retention time database of identified analytes and their respective retention times in a reference Gas Chromatograph (GC) system under locked conditions for identification of unknown analytes of interest eluting from any GC system locked to the retention time database and may also be employed in combination with selective detection and or method translation for enhanced certainty of identification.
摘要:
A data manipulation method to make local chromatography data more usable and comparable to a reference. The method provides time axis correction to better match local data to a reference of the same time scale, time axis transformation to correspond more directly to a reference based on a different time scale, and response axis correction to better match a reference of the same or different response scale, while maintaining the original peak areas. The method may be used along or concurrently with other data manipulation technique to facilitate operations such as searching, matching, visual comparison, mathematical manipulation, and pattern recognition of chromatographic data.
摘要:
A data manipulation method to make local chromatography data more usable and comparable to a reference. The method provides time axis correction to better match local data to a reference of the same time scale, time axis transformation to correspond more directly to a reference based on a different time scale, and response axis correction to better match a reference of the same or different response scale, while maintaining the original peak areas. The method may be used along or concurrently with other data manipulation technique to facilitate operations such as searching, matching, visual comparison, mathematical manipulation, and pattern recognition of chromatographic data.
摘要:
A preferred method for identifying analytes of samples by utilizing chemometric analysis for interpreting chromatographic data obtained under locked conditions includes the steps of: (1) providing a locking GC system which includes a column operated at a column head pressure; (2) adjusting the column head pressure of the locking GC system so that a column void time of the column in the locking GC system, when a known analyte is eluted therethrough, is matched with the column void time of the column in a reference GC system, when the known analyte is eluted therethrough; (3) analyzing the sample with the locking GC system so that chromatographic data corresponding to the sample is compiled, and; (4) performing chemometric analysis on the chromatographic data.
摘要:
The oxygen-selectivity of an atomic emission detection system is enhanced by introducing a carbon-containing, preferably non-oxygenated, gas as a portion of the reagent gas. In preferred embodiments, the reagent gas is nitrogen and/or hydrogen and up to about 50 volume percent of a C.sub.1 -C.sub.4 hydrocarbon gas.
摘要:
A solvent dumping apparatus is described having an inlet enclosure coupled to the inlet of a detector and an outlet enclosure coupled to the outlet of a detector. Venting means are provided for both enclosures, one of which is controllable; means are provided for introducing sample gas into the inlet enclosure; and means are provided for introducing gas into the outlet enclosure. During a detection mode, at least one of the venting means is so adjusted as to cause sample gas to flow through the detector and out the venting means for the outlet enclosure, and during a diversionary mode, at least one of the venting means is so adjusted as to cause the gas introduced into the outlet enclosure to pass back through the detector and carry any sample gas out through the venting means for the inlet enclosure. In preferred forms of the invention, one of the venting means is a back pressure regulator.
摘要:
A connector element for use with analytical devices is provided. The connector element includes a cavity for receiving a sealing member, and an access element for providing access to the sealing member when disposed in the cavity, e.g., for dislodging the sealing member from the connector element. Also provided are analytical devices that include the connector element, as well as methods of using the same.