This standard specifies the method for determining protein nitrogen in tobacco and tobacco products by the Kjærdahl method. This standard applies to tobacco and tobacco products. YC/T 166-2003 Determination of total protein content in tobacco and tobacco products YC/T166-2003 Standard download decompression password: www.bzxz.net
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YC/T166—2003 This standard is formulated based on ISO/C-5 and 3.148-3.15c of the American Association of Chemists (AAC) (14th edition). While referring to ISO/CD15677, the national tobacco industry's determination method for total rats is used to try to keep the same as YC/T3 in terms of the determination of the degree of achievable. It also refers to A0A (analysis of the strength of the material) 》This standard is proposed by the State Tobacco Administration. This standard is approved by the State Tobacco Standardization Technical Committee (ICI44). 1. The unit of this standard is: the State Tobacco Administration and Collection Center, the principal person in charge of this standard is Zhang Yan, Shangfang, Shi Cui, and Yang Jin. 1. Application Tobacco and tobacco products Determination of total protein content Three standards are currently determined. The "Krader method is used to determine the content of protein in tobacco products. This standard is applicable to ten continents and certain products. ? Current normative reference documents YC/T166—2003 The following clauses in their supporting parts become technical standards before being cited by the standard. All subsequent revisions (excluding internal consultation) or replacement editions are not applicable to this standard. However, the latest version of these documents or new editions shall apply to this standard according to the parties to the agreement reached on the release of the standard: H star undated reference documents, all latest versions are applicable to this standard, GB/F5 506.1 Principles of batch sampling in tobacco oils and tobacco products C: 3 Preparation and moisture measurement of tobacco and tobacco products 3 Principles of drying 7. The nitrogen in the slow-release tobacco samples is converted into acid under the action of concentrated acid and oxidant: strong evaporation releases positive hydrogen: allantoic acid is also absorbed, and the reaction is complete: 4 Reagents All reagents should be analytical grade, and water should be ethanol or 1% water of equal purity. 4. 1.2 Concentrated acid: 1.84 g/L (this component can cause severe burns) 4.3 Red ammonia water. 4.4 Acid short 4.5 Oxidized-sodium thiosulfate solution; sodium hydroxide and 10R thiosulfate (Na2SO4) concentrated in water, diluted to 1 1., 4.6 Acetic acid, mass number is 0.5, 4.7 Sulfuric acid, 0.1~0.1L, 4.8 Sulfur standard titration solution.c (0.5HS,>.-2.1mol/1..4. Sodium hydride standard titration solution, NOII) =, 1ao:4. Red indicator,%. 5 Instrument equipment 5 .1 Half flat. Accurate full 0.0002 5.2 Use this 120mm diameter Buchner funnel, select and install gastric extraction..3 Heat increase device 5Um grams of flask, connected with 4~ spherical condenser and 3 who Tong flask, 5.4 Huai flask 30mL 5.5 Schmidt flask, i00im1. YC/T166—2CG3 5. 6 Larger times, 2.1 ml. 5.7 Please specify 50mL (3.1mL scale): 5,8 Volume. 25 m.., 15 ml., 2EC m[..5.9 Specify filter paper, no table. 6 Analysis steps 6.1 Sampling 6.1.1 Tobacco leaves According to YC/T, take tobacco leaves as laboratory samples. 6.1.2 Cigarettes According to GB/TSt.1, take cigarettes as laboratory samples. E.2. Preparation of samples According to YC/T31, prepare samples. 6.3 Determination times Each sample shall be measured twice in parallel. 6.4 Determination of moisture content According to YC/T1, determine the moisture content of the sample. 5.5 Extraction Take about 100 ml of sample (accurate to 0.0002). Put the sample into 300 ml of male bottle 5). Use 75 ml of ethyl acetate 2). Heat and keep it at 131°C. Quickly filter with a fixed filter paper (less than 5.5) in the room oil (5.2) and rinse the flask and precipitate with acetic acid until the liquid is colorless. After heating, transfer the filter and precipitate to a Kjer flask 5.6.5 Digestion Add 2.7g of color oxide (4.3), 15% potassium hydroxide (1.1) and 25ml of concentrated sulfuric acid (4.2) to the Kjer flask and mix well. Move the powdered Kjer flask into a ventilated room, place it on a fixed air rack, with the neck at a 5-degree angle to the horizontal plane, and heat slowly. Wait until the particle depth is reached. After recording the solution, wash it with a 15% flask. Cool, 1 to about 5 ml.-7 g ml, and rinse the flask with water. 6.7 Distillation Add 200 ml of water to the Kjer flask, add light (1, > distillation), and carefully add the hydroxide ion and sodium hydroxide solution (4.57Pot). m... Immediately connect the hot shrink liquid to the conical flask (1) with 25 ml of standard clear solution (4.8) and 3-4 drops of indicator (1.10) as the receiver: cool the end of the solution in the acid and distill until the liquid level reaches 1:1. Note: Sodium hydrogen peroxide-sodium chloramine solution should be added carefully to prevent the temperature from rising rapidly and the color of the solution will be kept uniform. After the sample is fully diluted, remove the conical flask to avoid absorption of the solution. Rinse the cold end with water. 6. Titrate with sodium xanthocyanate standard solution (4.>Clear solution) until the indicator color turns red. 6.9 To test 6.9.1 Blank reagent test Use an equal amount of distilled water to replace the sample test. The endpoints of 6.6.57 and 6.% are valid equal points, and the Pu is set (E.) Avoid correction: If the error is small, the sample value can be corrected: If the error is large, find out whether a reagent has been introduced or a certain device has consumed hydrogen peroxide: correct the identification and repeat the test. Design: Low-confidence organic composite materials with impurities or deep readings may also cause the same reaction, 6.9.2 Instrument-only test 6.9.2.1 Test of distilled water weight YC/T 166—2003 Add 10T of distilled water (4.71% of sludge) to the distillation bottle and then continue the operation at 67% and 6.%. If the result is biased, it may be due to incomplete distillation or the device may be full at the end. Correct the error and repeat the test. Only the first ohm and pressure should be used. This test should be performed regularly. 6.9.2.2 Test method Determine the mixture of organic amino compounds with known oxygen content of 0.5g, lysine, amino acid, nitrogen and 0.5% dead organic Nitrogen compounds < earn or lose sugar "3.6, 6.7 and 6, 9 operation, the result is low. The original content of S.9.2.1, or due to the loss of digestion products, insufficient digestion (such as heating temperature is not appropriate knockout reagent quality is too poor). , the experiment was carried out for the first time using the slice method. Calculation and expression of results 7.1 Calculation method of protein content The protein content of the sample P is expressed as the white content ratio of the sample below, and the formula (1) is used to calculate: P 6. 25 × (,xxw VXe x1×139.---X(1-W)X1UUC 6.35-Conversion coefficient of protein; The volume of the standard solution consumed in blank titration is liter (ml). The volume of the acid standard solution is in liter (ml); W. The volume of the standard solution of hydrogen peroxide consumed in the blank titration is in milliliters (ml); The concentration of the standard sulfuric acid is in moles per liter (mO./L): 4 The concentration of the hydrogen peroxide standard solution is in moles per year (mol/L); The mass of the sample is in grams (g); The water content of the sample is in grams. 7.2 Expression of resultsbzxZ.net The average value of two parallel determinations shall be taken as the test result, accurate to 31%./, 3-shot density The difference in absolute values of two parallel determinations shall be 0.20, 1 Tip: This standard content only shows part of the intercepted content of the complete standard. If you need the complete standard, please go to the top to download the complete standard document for free.