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US 7,018,845 B2Granted
Method for staged oxidation for enhanced nitrogen and sulfur detection
AssigneePetroleum Analyzer Company, LP
InventorRandy L. Wreyford
Life of this patent
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Abstract
A more efficient method for combustion or oxidation of samples containing nitrogen, phosphorus and/or sulfur to their corresponding oxides is disclosed, where method uses multi-staged addition of an oxidizing agent to enhance oxidation and liberation of nitrogen, phosphorus and/or sulfur oxides for subsequent detection. The method of the present invention allows for the injection of larger samples or the introduction of a greater amount of sample per unit of time which results in a larger amount of analyte being delivered to the detector per unit of time, thereby improving detection limits and detection efficiency.
Claims56
A method for oxidizing samples comprising the steps of:
- introducing a sample and a first amount of an oxidizing agent into an oxidation chamber maintained at an elevated temperature, and
- introducing at least one additional amount of the oxidizing agent into the combustion chamber,
- where the combustion chamber comprises an inner tube having an interior and an exterior and an outer tube having an interior, where the first amount of oxidizing agent oxidizes the sample in a first combustion zone, which comprises the interior of the inner tube and the at least one additional amount of the oxidizing agent continues to oxidize the sample in a second combustion zone, which comprises a region between the exterior of the inner tube and the interior of the outer tube, where the first and additional amounts of the oxidizing agent are in excess of a stoichiometric amount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, where the oxidizable components are partially or completely convened into their corresponding oxides, and where the introduction the additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
A method for oxidizing samples comprising the steps of:
- introducing a sample and a first amount of an oxidizing agent into an oxidation chamber maintained at an elevated temperature, and
- introducing at least one additional amount of the oxidizing agent into the combustion chamber,
- where the combustion chamber comprises a U-shaped combustion tube and where the at least one additional amount of the oxidizing agent is introduced into the U-shaped combustion tube at about a turn in the U-shaped combustion tube, where the first and additional amounts of the oxidizing a gent are in excess of a stoichiometric a mount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, where the oxidizable components are partially or completely converted into their corresponding oxides, and where the introduction of the first and additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
A method for oxidizing samples comprising:
- mixing a sample with a first amount of an oxidizing agent to form an oxidizing mixture;
- introducing the oxidizing mixture into a first combustion zone of a combustion chamber;
- converting a portion of oxidizable components of the sample into their corresponding oxides;
- introducing a second amount of the oxidizing agent into a second combustion zone of the combustion chamber;
- partially or completely converting all oxidizable components of the sample into their corresponding oxides,
- where the combustion chamber comprises an inner tube having an interior and an exterior and an outer tube having an interior, where the first amount of oxidizing agent oxidizes the sample in a first combustion zone, which comprises the interior of the inner tube and the at least one additional amount of the oxidizing agent continues to oxidize the sample in a second combustion zone, which comprises a region between the exterior of the inner tube and the interior of the outer tube, where the first and additional amounts of the oxidizing agent are in excess of a stoichiometric amount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, where the oxidizable components are partially or completely converted into their corresponding oxides, and where the introduction of the first and additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
3 more elements
A method for oxidizing samples comprising:
- mixing a sample with a first amount of an oxidizing agent to form an oxidizing mixture;
- introducing the oxidizing mixture into a first combustion zone of a combustion chamber;
- converting a portion of oxidizable components of the sample into their corresponding oxides;
- introducing a second amount of the oxidizing agent into a second combustion zone of the combustion chamber;
- partially or completely converting all oxidizable components of the sample into their corresponding oxides,
- where the combustion chamber comprises a U-shaped combustion tube and where the at least one additional amount of the oxidizing agent is introduced into the U-shaped combustion tube at about a turn in the U-shaped combustion tube, where the first and additional a mounts of the oxidizing agent are in excess of a stoichiometric a mount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, the oxidizable components are partially or completely converted into their corresponding oxides, and where the introduction of the first and additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
3 more elements
A method for oxidizing samples comprising:
- separating a sample into its components in a separation apparatus;
- mixing each component with a first amount of an oxidizing agent;
- introducing each component and a first amount of the oxidizing agent into a combustion chamber maintained at an elevated temperature;
- converting a portion of oxidizable components of the sample into their corresponding oxides;
- introducing at least one additional amount of the oxidizing agent;
- and
- partially or completely converting each component of the sample into its corresponding oxides,
- where the combustion chamber comprises an inner tube having an interior and an exterior and an outer tube having an interior, where the first amount of oxidizing agent oxidizes the sample in a first combustion zone, which comprises the interior of the inner tube and the at least one additional amount of the oxidizing agent continues to oxidize the sample in a second combustion zone, which comprises a region between the exterior of the inner tube and the interior of the outer tube, where the first and additional amounts of the oxidizing agent are in excess of a stoichiometric amount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, where the oxidizable components are partially or completely converted into their corresponding oxides, and where the introduction of the first and additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
5 more elements
A method for oxidizing samples comprising:
- separating a sample into its components in a separation apparatus;
- mixing each component with a first amount of an oxidizing agent;
- introducing each component and a first amount of the oxidizing agent into a combustion chamber maintained at an elevated temperature;
- converting a portion of oxidizable components of the sample into their corresponding oxides;
- introducing at least one additional amount of the oxidizing agent;
- and
- partially or completely converting each component of the sample into its corresponding oxides,
- where the combustion chamber comprises a U-shaped combustion tube and where the at least one additional amount of the oxidizing agent is introduced into the U-shaped combustion tube at about a turn in the U-shaped combustion tube, where the first and additional a mounts of the oxidizing agent are in excess of a stoichiometric a mount of oxidizing agent needed to completely convert all oxidizable components in the sample into their corresponding oxides, where the oxidizable components are partially or completely converted into their corresponding oxides, and where the introduction of the first and additional amounts of oxidizing agent improves an oxidation efficiency of the combustion chamber.
5 more elements
Dependencies are inferred from the claim text.