Analytical method for the determination of nitrogen, carbon, hydrogen and sulfur or chlorine and apparatus therefor

Claim 1

A method for elementary analysis by independent or simultaneous determination of any number of elements from the group consisting of nitrogen, carbon, and hydrogen and at least one element of sulfur or chlorine in samples, comprising: passing an oxygen gas through a combustion system in a reaction tube packed with an oxidation catalyst or oxidizing agent having a heating zone maintained at a temperature of from 800° C. to 1100° C.; introducing a sample into said reaction tube with circulating oxygen in a closed system, said oxygen being present in an amount sufficient to thereby subject said sample to complete combustion and said circulating oxygen uniformalizing the resulting combustion gas by continuous circulation during combustion to achieve a homogeneous combustion gas mixture; dividing the homogeneous combustion gas mixture into first and second combustion portions in a definite volume ratio; introducing said first combustion portion, together with a carrier gas, into a reduction tube packed with reduced copper having a heating zone maintained at a temperature of from 400° C. to 700° C., and detecting and determining the resulting nitrogen gas, carbon dioxide gas and steam or acetylene gas or hydrogen gas produced by contacting steam with calcium carbide or calcium hydride; while introducing sulfur oxide or chlorine and/or hydrogen chloride gas contained in said second combustion mixture into an absorption liquor together with oxygen gas; and detecting and determining at least one of the resulting sulfate or chloride ion.

Claim 2

A method for elementary analysis by independent or simultaneous determination of any number of elements from the group consisting of nitrogen, carbon, and hydrogen and at least one element of sulfur or chlorine in samples, comprising: passing an oxygen gas through a combustion system in a reaction tube packed with an oxidation catalyst or oxidizing agent having a heating zone maintained at a temperature of from 800° C. to 1100° C.; introducing a sample into said reaction tube with circulating oxygen in a closed system, said oxygen being present in an amount sufficient to thereby subject said sample to complete combustion and said circulating oxygen uniformalizing the resulting combustion gas by continuous circulation during combustion to achieve a homogeneous combustion gas mixture; dividing the homogeneous combustion gas mixture into first and second combustion portions in a definite volume ratio; introducing said first combustion portion, together with a carrier gas, into a reduction tube packed with reduced copper having a heating zone maintained at a temperature of from 400° C. to 700° C., and detecting and determining the resulting nitrogen gas, carbon dioxide gas and steam or acetylene gas or hydrogen gas produced by contacting steam with calcium carbide or calcium hydride; while introducing sulfur oxide or chlorine and/or hydrogen chloride gas contained in said second combustion mixture into an absorption liquor together with oxygen gas; and detecting and determining at least one of the resulting sulfate or chloride ion.

Claim 8

An apparatus for elementary analysis by independent or simultaneous determination of any number of elements from the group consisting of nitrogen, carbon and hydrogen and at least one element of sulfur or chlorine in samples comprising: a closed combustion system for combusting a sample to be analyzed, said closed combustion system including a gas recirculation means for continuous circulation of gases contained within the combustion system, thereby uniformalizing the resulting combustion gas to achieve a homogeneous gas mixture; an oxygen gas line-changing means for selectively alternating an oxygen gas feed to said combustion means in a closed system or to an absorption means; a combustion gas division means for dividing the homogeneous combustion gas mixture into first and second combustion portions in a definite volume ratio and simultaneously introducing said first combustion portion of the homogeneous combustion gas mixture into a carrier gas; a reduced copper-packed reduction means for reducing nitrogen oxides contained in the mixture of said first combustion portion and said carrier gas to nitrogen gas and simultaneously removing oxygen gas; a gas separation means for separating the resulting gas; a gas detection means for detecting gas thus separated; a combustion gas absorption means for absorbing and collecting sulfur oxide or chlorine and/or hydrogen chloride gas contained in said second combustion portion; and an absorbed gas detection means for detecting gases thus absorbed in said gas absorption means.

Claim 9

An apparatus for elementary analysis by independent or simultaneous determination of any number of elements from the group consisting of nitrogen, carbon and hydrogen and at least one element of sulfur or chlorine in samples comprising: a closed combustion system for combusting a sample to be analyzed, said closed combustion system including a gas recirculation means for continuous circulation of gases contained within the combustion system, thereby uniformalizing the resulting combustion gas to achieve a homogeneous gas mixture; an oxygen gas line-changing means for selectively alternating an oxygen gas feed to said combustion means in a closed system or to an absorption means; a combustion gas division means for dividing the homogeneous combustion gas mixture into first and second combustion portions in a definite volume ratio and simultaneously introducing said first combustion portion of the homogeneous combustion gas mixture into a carrier gas; a reduced copper-packed reduction means for reducing nitrogen oxides contained in the mixture of said first combustion portion and said carrier gas to nitrogen gas and simultaneously removing oxygen gas; a gas separation means for separating the resulting gas; a gas detection means for detecting gas thus separated; a combustion gas absorption means for absorbing and collecting sulfur oxide or chlorine and/or hydrogen chloride gas contained in said second combustion portion; and an absorbed gas detection means for detecting gases thus absorbed in said gas absorption means.