DD207579A1 - METHOD FOR THE QUANTITATIVE DETERMINATION OF THE ORIGINAL BZW. TOTAL NITROGEN CONTENT IN ALL PROTEIN SUPPLEMENTS AND AMMONIA CONTENT IN ORGANIC MATERIAL - Google Patents

Abstract

A method for determining the protein content in all protein carriers is recommended, which requires the smallest amount of substance due to the sensitivity and the reproducibility and accordingly results in a significant saving in energy, chemicals and time. At the same time, a method for the determination of the ammonia content in feed, food and body fluids is proposed, which represents a substantial simplification of the previously used examination technique.

Description

Title of the invention

Method for the quantitative determination of the protein or total nitrogen content in all protein carriers and of the ammonia content in organic material

Field of application of the invention

The invention relates to a method for the quantitative determination of the protein content or the content of total nitrogen in all protein carriers (feed, food, body fluids, skeletal, Biosehlamm- and faeces samples) and the ammonia content in feed, food, body fluids and water ,,>

Characteristic of the known technical solution

The determination of the protein content in the organic material mainly uses methods based on the conversion of the nitrogen contained in the building blocks of the proteins. The nitrogen contained in the amino acids is converted into ammonia. The determined ammonia content can be converted into protein with an empirical factor. Methods for the direct determination of the protein content could not prevail so far, because they do not meet the requirements of the routine examination and are not universally applicable _#

The methods used to determine the protein content in feed, food, body fluids and other biological material, require due to high or relatively

13.! ViAi 19 82 * 009360

2 2

high sample weights large amounts of energy, time and a certain amount of equipment · In addition, larger amounts aggressiever acid vapors, which adversely affect the laboratory facilities and the laboratory atmosphere, arise. There are essentially three methods, the z _# · Zt for determining the protein content in the above-mentioned "substrates set routinely mono-> · These are the determination method by the Kjeldahl method, die'Indophenolblau reaction according to the Kjeldahl digestion and Determination method according to the dye-binding principle. The method according to Kjeldahl requires by the large amount of sample a significant amount of energy for the digestion and leads by development of large amounts of acidic acid to the deterioration of the laboratory equipment and the laboratory air. The remaining methods still require relatively high Probeneinwaagen, accordingly also a greater expenditure of energy and a certain amount of equipment

Object of the invention

The aim of the invention is to quantitatively detect the smallest possible ammonia concentrations by using a reagent which reacts very sensitively and under certain conditions analytically to ammonia, in order to calculate the protein content from it.

The use of very small quantities makes it possible to drastically reduce the expenditure of energy, time and chemicals as well as the expenditure on equipment.

The invention is based on the object, an analytical method for all analyzed protein carrier and for ammonia. to develop containing substrates and liquids in order to achieve a considerable saving in energy, time and equipment expenditure, especially in the case of large series, of the extensive routine testing of feed and food samples by a minimum sample balance.

ia MA1198.2 * 009360

I ό Ö Q ÖZZ

Explanation of the essence of the invention ;

According to the invention, this object is achieved by heating the test material in the test tube with 0.j ml of concentrated sulfuric acid in the test tube, adding 0.2 to 0.5 ml of hydrogen peroxide (30% strength) and by diluting the digested sample, 0.1 ml of dipotassium tetragodomercurate solution (saturated) is added to an aliquot, and the absorbance of the solution is measured preferably at 415r in a 1 cm cuvette against double-distilled water «The proposed method of determination allows fast and exaki: determination of ammonia content or total nitrogen content, from which the protein content can be calculated easily kar

Exemplary embodiments

The process according to the invention will be explained in more detail with reference to the following examples.

100 mg of a diluted sample in the dry way 1:10 conc i a test tube with 0.5 ml. Sulfuric acid added. The glass is placed in one of the boreholes of the heating block, which is placed on a laboratory cooker. »After the first acid vapors have appeared, they are cooled and then .3 ml hydrogen peroxide (30%) is added. The heating is continued until the sample is colorless.

The so-digested sample is rinsed ge in a 100 ml volumetric flask and the flask filled with deionized water to 100 ml.

Dissolve 2 ml of the sample thus diluted with 0.1 ml reagent (Dikali umtetrajodomerkurat, - supernatant of the saturated solution). Displacement The absorbance can after 10 min at 415 am against double-distilled water. be measured in a 1 cm cuvette.

Based on a calibration curve, the ammonia content is determined from which the protein or protein content can be calculated by multiplying by a given factor.

iaiAAI1 ^: 982 * 0ti9-36-0 '

1 ml of rumen juice is rinsed in a 100 ml volumetric flask and made up to 100 ml with deionized water. An aliquot (2 ml) of wind is added after centrifuging with 0.1 ml of reagent. The extinction is measured 10 min. Thereafter, preferably at 415 ml. Against double-distilled water, *

Claims (2)

-S 238882 2 Sr-f claim    ----, j Method for the quantitative determination of the protein or "total nitrogen content in all protein carriers and the ammonia content in the organic material, characterized in that biological material preferably digested with concentrated sulfuric acid ün hydrogen peroxide (30%), and an aliquot with dipotassium tetrajodomycurate Solution and the resulting yellowing can be measured with a photometer, preferably at 415 nm. 2 * 009360