Method for detecting nitrogen in carburant by Kjeldahl apparatus

Abstract

The invention provides a method for detecting nitrogen in a carburant by a Kjeldahl apparatus. The method comprises the following steps of (1) preparing a test specimen: sieving a to-be-detected sample dried by the air by a sieve screen being 80 meshes; taking out the sample; then putting the sample into a drier for measurement; (2) dissolving the sample by a digestion furnace; (3) performing distillation by the Kjeldahl apparatus and hydrochloric acid titration; (4) performing blank reference experiments; (5) calculating the nitrogen element content. The nitrogen element in the carburant is fast detected through the Kjeldahl apparatus. During the detection, the selectivity is high; simplicity and convenience are realized; the speed is high; the accuracy is realized; the method is applicable to the detection of nitrogen elements of a great number of samples in a wide range.

Description

technical field [0001] The invention relates to the technical field of chemical analysis, in particular to a method for detecting nitrogen in a carburant by a Kjeldahl nitrogen analyzer. Background technique [0002] There are many types of recarburizers, including graphite, petroleum coke, coke, and coal. The nitrogen content of various carburizers is high or low. According to actual tests, the mass fraction of nitrogen content ranges from 0.10% to 3%. There is no national standard or corresponding standard for the determination of the nitrogen content of carburizers. Samples, the determination of the nitrogen content in the carburant can refer to the "GB / T19227-2008 Determination of Nitrogen in Coal", that is, the semi-trace Kelvin method or the semi-trace steam method. The standard sample is a coal standard sample, but this method is The chemical method has many steps, takes a long time, and the allowable difference of the analysis data is large. The chemical samples use...

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Problems solved by technology

[0002] There are many types of recarburizers, including graphite, petroleum coke, coke, and coal. The nitrogen content of various carburizers is high or low. According to actual tests, the mass fraction of nitrogen content ranges from 0.10% to 3%. There is no national standard or corresponding standard for the determination of the nitrogen content of carburizers. Samples, the determination of the nitrogen content in the carburant can refer to the "GB / T19227-2008 Determination of Nitrogen in Coal", that is, the semi-trace Kelvin method or the semi-trace steam method. The standard sample is a coal standard sample, but this method is The chemical method has many steps, takes a long time, and the allowable difference of the analysis data is large. The chemical samples used are not conducive to environmental protection. At the same time, the nitrogen content of the coal standard substances sold by standard units such as the Coal Research Institute is less than 1.5%, which cannot meet the high requirements. The determination of nitrogen samples can also be carried out by the inert gas fusion-thermal conductivity method for the determination of the nitrogen element of the micro-nitrogen recarburizer. The equipment for the inert fusion-thermal conductivity method is an oxygen and nitrogen detector to measure low-level oxygen and nitrogen elements. The nitrogen content in the carburant sample varies from high to low, as high as 3%. The inert melting-thermal conductivity method cannot fully meet the detection requirements of carburant in all content ranges. At the same time, the carburant is a powder sample. During the measurement process , will pollute the gas path of the oxygen and nitrogen meter, and the inspection of a large number of samples is not conducive to the normal use of the instrument

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