This standard specifies the determination method of water-soluble sugars in tobacco. This standard applies to tobacco products. YC/T 159-2002 Determination of water-soluble sugars in tobacco and tobacco products Continuous flow method YC/T159-2002 Standard download decompression password: www.bzxz.net

ICS 65. 160
Reference number: 10589—2002
Tobacco Industry Standard of the People's Republic of China
YC/T159-2002
Tobacco and tobacco products
Determination of watersoluble sugars -Continuous flow method
Tobacco and tobacco products-Determination of watersoluble sugars -Continuous flow method2002~0912PublishedWww.bzxZ.net
Published by the State Tobacco Monopoly Administration
Implemented on 2002-12-01
YC/T159—2002
This standard is equivalent to the recommended method No. 38 of the International Tobacco Scientific Research Cooperation Center (CORESTA). The main technical differences between this standard and the CORESTA recommended method No. 38 are as follows: the determination of total water-soluble sugars is added, so that this method can determine water-soluble reducing sugars and total sugars. Studies have shown that the results of determination using this standard may be higher than those of YC/T32, which is caused by different determination principles. This standard is proposed by the State Tobacco Monopoly Administration. This standard is under the jurisdiction of the National Tobacco Standardization Technical Committee. The drafting unit of this standard: National Tobacco Quality Supervision and Inspection Center. The main drafters of this standard: Liu Huimin, Li Ping, Li Rong, Wang Fang. 398
1 Scope
Determination of water-soluble sugars in tobacco and tobacco products Continuous flow method
This standard specifies the determination method of water-soluble sugars in tobacco. This standard applies to tobacco and tobacco products. 2 Normative references
YC/T159—2002
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated referenced documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties to the agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated referenced documents, the latest versions are applicable to this standard. GB/T5606.1 Cigarette sampling
YC/T5 General principles for batch sampling of tobacco leaves
YC/T31 Preparation of tobacco and tobacco product samples and determination of moisture content Oven method 3 Principle
Use 5% acetic acid aqueous solution to extract tobacco samples. The sugar in the extract (water-soluble total sugar should be hydrolyzed when determining it) reacts with p-hydroxybenzoic acid hydrazide to produce a yellow azo compound in an alkaline medium at 85°C. Its maximum absorption wavelength is 410nm and is determined by a colorimeter. Note: If water is used for extraction, the sucrose in some samples will be hydrolyzed. 4 Reagents
Use analytical grade reagents. Water should be distilled water or water of equivalent purity. 4.1 Brij35 solution (polyethoxylated lauryl ether) Add 250g Brij35 to 1L water and heat and stir until dissolved. 4. 20.5 mol/L sodium hydroxide solution
Add 20g of sodium hydroxide flakes to 800mL of water, stir, and let it cool. After dissolving, add 0.5mL of Brij35 (4.1), and dilute with water to 1L.
4.30.008mol/L calcium chloride solution
Dissolve 1.75g ​​of calcium chloride (CaCl2·6H,O) in water, add 0.5mL of Brij35 solution (4.1), and dilute with water to 1L. Note: If there is precipitation in the solution, use qualitative filter paper to filter. 4.45% acetic acid solution
Use glacial acetic acid to prepare 5% acetic acid solution (this solution is used to prepare standard solution and extraction solution). 4.5Activation of 5% acetic acid solution
Take 1L of 5% acetic acid solution (4.4), add 0.5mL of Brij35 solution (4.1) (this solution is used to flush the system). 4.6 0.5 mol/L hydrochloric acid solution
In a fume hood, slowly add 42 mL of fuming hydrochloric acid (mass fraction is 37%) to 500 mL of water, and dilute with water to 1 L. 4. 7 1. 0 mol/L hydrochloric acid solution
YC/T 1592002
In a fume hood, slowly add 84 mL of fuming hydrochloric acid (mass fraction is 37%) to 500 ml of water, add 0.5 mL of Brii35 solution (4.1), and dilute with water to 1 L.
4. 8 1. 0 mol/L sodium hydroxide solution
Dissolve 40 g of flaky sodium hydroxide in 500 mL of water, and dilute with water to 1 L. 4.95% p-hydroxybenzoic acid hydrazide solution (HOCgH.CONHNH2) Add 250mL 0.5mol/L hydrochloric acid solution (4.6) to a 500mL volumetric flask, such as 25g p-hydroxybenzoic acid hydrazide, and dissolve it. Add 10.5g citric acid [HOC(CH,COOH),COOH·H,O], dissolve it and dilute it to the mark with 0.5mol/L hydrochloric acid solution. Store at 5°C and take only the required amount when using. Note: The purity of p-hydroxybenzoic acid hydrazide (mass fraction greater than 97%) is very important. If there are impurities, a precipitate will form in the pipeline. It can be purified by recrystallization from water. The following situations indicate that p-hydroxybenzoic acid hydrazide is impure: black particles in the white p-hydroxybenzoic acid hydrazide crystals; -5% p-hydroxybenzoic acid hydrazide solution is yellow; p-hydroxybenzoic acid hydrazide is difficult to dissolve in 0.5moi/L sodium hydroxide solution; there are suspended particles in the solution;
——the baseline is wavy.
5% p-hydroxybenzoic acid hydrazide solution can also be prepared by the following method: add 250ml: 0.5mol/L hydrochloric acid solution to a beaker, heat to 45C, add p-hydroxybenzoic acid hydrazide and citric acid under continuous stirring, transfer to a volumetric flask after cooling, and dilute to the scale with hydrochloric acid solution. The p-hydroxybenzoic acid hydrazide solution prepared in this way can avoid the formation of precipitation in the pipeline. 4.10 D-glucose
4.11 Standard solution
4.11.1 Stock solution: Weigh 10.0g D-glucose (4.10) in a beaker, accurate to 0.0001g, dissolve it with 5% acetic acid solution (4.4), transfer it to a 1L volumetric flask, and dilute to the mark with 5% acetic acid solution. Store in a refrigerator. This solution should be prepared once a month. 4.11.2: Working standard solution: Prepare at least 5 working standard solutions from the stock solution with 5% acetic acid solution, and the concentration range should cover the sample content expected to be detected. The working standard solution should be stored in a refrigerator and prepared once every two weeks. 5 Instruments and equipment
Common experimental instruments and
5.1 Continuous flow analyzer (see Figure 1), composed of the following parts: a sampler;
a proportional pump;
dialyzer;
a heating tank:
spiral tube;
a colorimeter with a 410nm filter;
recorder.
5.2 Balance, sensitivity 0.0001g.
5.3 Oscillator.
6 Analysis steps
6.1 Sampling
Take samples according to GB/T5606.1 or YC/T5. 6.2 Prepare samples according to YC/T31 and determine the moisture content. 6.3 Weigh 0.25g of the sample into a 50ml ground-mouth conical flask, accurate to 0.0001g, add 25mL of 5% acetic acid solution, cover with a stopper, and oscillate and extract on an oscillator at 400°C for 30min.
6.4 Filter with qualitative filter paper, discard the first few milliliters of filtrate, and collect the subsequent filtrate for analysis. YC/T 159--2002
6.5 Run the working standard solution and sample solution on the machine. If the concentration of the sample solution exceeds the concentration range of the working standard solution, it should be diluted. 7.79 mL heated sugar
7. 79 mL heated sugar solution
152mm (6 inches)
410mm glass film
12.0mm×15mm flow cell
black/black (0. 32 mL/min), air
red/red (0. 80 mL/min), 1. 0 mol/L hydrochloric acid (or water) white/white (0.60 mL/min), Xiangpin
red/red 2 (0.80 mL/min), 1.0 mol/L sodium hydroxide (water) Cheng/white (0. 23 mL/min), PAHBAH/connection (0. 42 mL/min). Air
green/green (2. 0 mL/min), 0. 5 mol/L sodium hydroxide Lou/yellow (0. 16 mL/min), 0.008 mol/L calcium hydride red/red (0.80 mL/min), 5% acetic acid
Figure 1 Diagram of the pipeline for water-soluble sugar determination
Note: When determining total sugar, red/red is 1.0mol/L hydrochloric acid, 95℃ heating tank open, when determining reducing sugar, red/red tube is activated water, red/red2 tube is water, 95℃ heating tank closed.
Calculation and expression of results
7. 1 Calculation of water-soluble sugar
The content of water-soluble sugar on a dry basis, calculated as glucose, is obtained by formula (1): cxv
m×(iw)× 100
Total (reducing) sugar (%)=
Where:
The instrumental observation value of total (reducing) sugar of the sample solution, in milligrams per liter (mg/ml.); V——the volume of the extract, in milliliters (mL); m——the mass of the sample, in milligrams (mg); W——the water content of the sample.
7.2 Expression of results
The average of the two determinations is taken as the determination result. (1)
If the measured water-soluble sugar content is greater than or equal to 10.0%, the result shall be accurate to 0.1%; if it is less than 10.0%, the result shall be accurate to 0.01%. 8 Precision
The absolute value difference between two parallel determination results shall not be greater than 0.50%. 401
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