Gas chromatographic method for the multi-elemental microanalysis of organic materials

摘要

Microanalytical method for the simultaneous determination of the elements, carbon, hydrogen, sulfur, chlorine, bromine, iodine and nitrogen in a single, small sample of an organic material, said method comprising the steps of: (a) substantially instantaneously igniting and rapidly and completely combusting a small sample of limited size in a heated combustion zone in a pressurized atmosphere of substantially pure oxygen; (b) conducting the gaseous mixture of combustion products in excess oxygen through a heated equilibrium zone; (c) conducting the effluent from the equilibrium zone through a gas chromatographic separation zone containing an adsorbent material adapted to separate combustion products of the said elements each from the others; (d) conducting the effluent from the separation zone through detecting means to quantitatively and separately measure the amount of the combustion product of each of the elements; (e) calculating from the amounts of the several combustion products the percentage content of each of the elements, carbon, hydrogen, sulfur, chlorine, bromine and iodine, in the organic material; and, for the determination of nitrogen, the additional steps of: (f) conducting at least that portion of the effluent from the said detecting means which contains substantially all of the combustion products of nitrogen, through a heated reduction zone; (g) conducting the effluent from the reduction zone through a cooled nitrogen-adsorption zone; (h) conducting a stream of inert gas through the nitrogen- adsorption zone while raising the temperature of that zone to desorb the nitrogen; (i) conducting the effluent from the nitrogen-adsorption zone, consisting essentially of nitrogen and inert carrier gas, through secondary detecting means to quantitatively measure the amount of nitrogen in the sample, and (j) calculating from the amount measured the nitrogen content of the organic material.