Preparation and measurement of ultra micro amounts of nitrogen

Claim 2

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via conduit means with measuring means for measuring the amount of nitrogen in the system; and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system being adapted for communication with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said conduit means between said combustion tube and said first means; and including means to communicate said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 3

An apparatus according to claim 1, wherein said first means disposed in said conduit means comprises first and second cold traps for condensing or solidifying said gaseous combustion products, and a reduction tube interconnecting said traps for reducing oxides of nitrogen to nitrogen and removing unconsumed oxygen; and said measuring means comprises a vacuum gauge for measuring nitrogen pressure; and further including furnace means for said reduction tube and furnace means for said combustion tube.

Claim 4

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system being adapted for communication with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said conduit means between said combustion tube and said first means; and including means to communicate said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 5

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system being adapted for communication with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said conduit means between said combustion tube and said first means; and including means to communicate said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 6

An apparatus according to claim 3, wherein said first means disposed in said conduit means comprises first and second cold traps for condensing or solidifying said gaseous combustion products, and a reduction tube interconnecting said traps for reducing oxides of nitrogen to nitrogen and removing unconsumed oxygen; and further including furnace means for said reduction tube and furnace means for said combustion tube.

Claim 7

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, measuring means disposed in said conduit means to measure the amount of nitrogen in the system; and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system being adapted for communication with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said conduit means between said combustion tube and said first means; and including means to communicate said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 8

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, measuring means disposed in said conduit means to measure the amount of nitrogen in the system; and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system being adapted for communication with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said conduit means between said combustion tube and said first means; and including means to communicate said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 9

An apparatus according to claim 5, wherein said first means disposed in said conduit means comprises first and second cold traps for condensing or solidifying gases other than nitrogen, and a reduction tube interconnecting said traps for reducing oxides of nitrogen to nitrogen and removing unconsumed oxygen; and said measuring means comprises a vacuum guage for measuring nitrogen pressure; and further including furnance means for said reduction tube and furnace means for said combustion tube.

Claim 10

An apparatus according to claim 5, including a second vacuum tight valve means disposed in said conduit means between said measuring means and said spectrometer for directing the nitrogen gas to the spectrometer.

Claim 13

A method according to claim 8, in which (in step iii) gases other than nitrogen and nitrogen oxides from said combusting are condensed or solidified in a first cold trap means, whereafter oxides of nitrogen are reduced to nitrogen, oxygen is removed by formation of copper oxides and residual gases other than nitrogen are condensed or solidified in a second cold trap means; and (in step iv) said measuring comprises determining the nitrogen pressure with a vacuum gauage.

Claim 14

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via a first conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, measuring means disposed in said first conduit means to measure the amount of nitrogen in the system; and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system communicating via a second conduit means with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said first conduit means between said combustion tube and said first means; and including third conduit means communicating said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 15

An ultra micro analysis apparatus of small internal volume for determination of the nitrogen content of nitrogen-containing matter comprising a system which comprises a combustion tube communicating via a first conduit means with a spectrometer for the stable isotope spectrometric analysis of nitrogen, measuring means disposed in said first conduit means to measure the amount of nitrogen in the system; and first means disposed in said conduit means for removing non-nitrogen-containing gaseous combustion products of said matter from the gaseous state and for converting gaseous nitrogen oxides to nitrogen gas; said system communicating via a second conduit means with evacuation means for controlled evacuation of the apparatus; a first vacuum tight valve means disposed in said first conduit means between said combustion tube and said first means; and including third conduit means communicating said combustion tube with means for introducing oxygen gas to the combustion tube.

Claim 16

An apparatus according to claim 10, wherein said spectrometer is an emission spectrometer; and said measuring means comprises a vacuum gauge for measuring nitrogen pressure.

Claim 17

An apparatus according to claim 11, wherein said first means comprises first and second cold traps for condensing or solidifying said gaseous combustion products, and a reduction tube interconnecting said traps for reducing oxides of nitrogen to nitrogen and removing unconsumed oxygen.