CS223307B1 - The method of elemental analysis of sulfur, or simultaneous determination of carbon, nitrogen and sulfur - Google Patents

Abstract

The invention relates to the analysis of sulfur by burning a sample in a stream of inert gas with the addition of oxygen and using a combustion charge. The essence of the method is that the substance is first pyrolyzed in a gas stream and these gases are led through a layer of tin dioxide and then a layer of wire-like copper, a layer of metal antimony and finally a layer absorbing water into the dilution chamber. The invention is intended for the chemical analysis of gaseous substances.

Description

(54) A method of elemental analysis of sulfur, where appropriate the simultaneous determination of carbon, nitrogen and sulfur

The invention relates to the analysis of sulfur by burning a sample in an inert gas stream with the addition of oxygen and using a combustion charge.

The essence of the method is that the substance first pyrolyses in the gas stream, and these gases are passed through a tin oxide layer and then a copper wire layer, a metal antimony layer and finally a water absorbing layer into the dilution chamber.

The invention is intended for chemical analysis of gaseous substances.

The invention describes a method of elemental analysis of sulfur or simultaneous determination of sulfur, carbon and nitrogen, by burning a sample in an inert gas stream with the addition of oxygen and using a combustion charge.

At present, great attention is being paid to the development of new instrumental methods for the determination of sulfur or the simultaneous determination of sulfur, carbon, nitrogen and hydrogen. In most cases, oxidative pyrolysis of the sample and the oxidation of pyrolysis products in a short layer of granulated tungsten oxide at 1000 ° C, conversion of sulfur trioxide to sulfur in the copper layer, where also to reduce nitrogen oxides and absorb unreacted oxygen are used. Disturbing halogens are partially captured on copper, silver, deposited on copper, or 8-hydroxyquinoline. There are difficulties with quantitative sample conversion for larger batches (over 1 mg) and also with the sorption of product reactions in the reaction and separation system, so that the results of sulfur determination worse than normally required in elemental analysis are obtained.

These previous disadvantages are eliminated by the method of determination of sulfur, or at the same time determination of carbon, nitrogen and sulfur by combustion of the sample in an inert gas stream, for example helium with oxygen, which is based on pyrolysis gases passing through a layer of granulated tin oxide. , a layer of granulated metal antimony and a water absorbing layer, into a dilution chamber, where they are homogenized at a temperature of 20 to 100 ° C, a pressure of 10 to 30 kPa, a volume of 100 to 1000 ml, and then separated and determined.

The advantage of the described method over the methods used up to now is the higher efficiency of the reaction packings and hence the achieved accuracy of the assay.

Samples for carrying out the method of the invention

Claims (1)

Subject Method for the determination of sulfur, or simultaneous determination of carbon, nitrogen and sulfur by combustion of a sample in an inert gas stream, for example helium with added oxygen, characterized in that the pyrolysis gases are passed through a granular tin oxide layer then weighing from 1 to 1.5 mg into aluminum boats and overlaps with a 1: 1 mixture of powdered tungsten tin oxide for complete conversion of pyrolysis products, conversion of sulfur trioxide to sulfur and reduction of nitrogen oxides, or absorption of unreacted oxygen in the copper layer, absorption of interfering halogens and water with a sorbent layer, for example Anhydrone, and then introduced into the dilution chamber. The dilution chamber-analyzer for this purpose is described, for example, in AO 157 857. This device is intended for elemental analysis of carbon, hydrogen, nitrogen and oxygen. The apparatus is equipped with a 26 cm double furnace for reaction quartz tubes of approximately 10 mm inside diameter. In the determination of carbon, nitrogen and sulfur, or sulfur alone, by the method of the invention, the pyrolysis and reaction portion of the sample tube is filled 6 cm from the furnace edge with a 2 to 3 cm layer of compressed quartz, then an 8 cm long granular oxide layer. tinny grain 0,5 to 1,0 mm, short layer of quartz wool, about 6 cm long layer of wire-woven copper, short layer of quartz wool, 2 cm long layer of crushed metal antimony grain 0,5 to 1,0 mm and short layer of quartz wool . The temperature of the pyrolysis part and the tin oxide combustion charge is maintained at 1000 + 50 ° C, the copper layer at 850 + 50 ° C, the antimony layer at ambient temperature (outside the furnace) · A water absorber filled with Anhydron is placed downstream of the combustion tube. Helium is used as the carrier gas, the optimum flow rate through the reactor being 100 to 1:20 ml / min. A mixture of nitrogen, carbon dioxide, sulfur dioxide and helium is analyzed. OF THE INVENTION A woven or granulated copper layer, a granulated metal antimony layer, and a water absorbing layer into a dilution chamber are homogenized from 20 to 100 ° C, 10 to 30 kPa pressure, 100 to 1000 ml volume, then separated and determined.