YC/T 160-2002 Determination of total alkaloids in tobacco and tobacco products - Continuous flow method
Some standard content:
ICS 65. 160
Preparation number: 10590--2002bZxz.net
Tobacco Industry Standard of the People's Republic of China
YC/T 160 --- 2002
Tobacco and tobacco products
Determination of total alkaloids
Continuous flow method
Tobacco and tobacco products-Determination of total alkaloidsContinuous flow method
Issued on September 12, 2002
State Tobacco Monopoly Administration
Implemented on December 1, 2002
YC/T160--2002
This standard is equivalent to the recommended method No. 35 of the International Tobacco Scientific Research Cooperation Center (CORESTA). The main technical differences between this standard and the CORESTA recommended method No. 35 are as follows: Different reference standards. These reference standards include the extraction, preparation and determination of the purity of nicotine or nicotine salts of samples. The operating methods specified in these reference standards are slightly different from the operating methods of the reference standards specified in CORESTA Recommendation No. 35. 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 Rong, Li Ping, Wang Fang 404
1 Scope
Tobacco and tobacco products
Determination of total alkaloids
Continuous flow method
This standard specifies the determination method of total alkaloids in tobacco. This standard is applicable to tobacco and tobacco products. 2 Normative reference documents
YC/T 160--2002
The provisions in the following documents become the provisions of this standard through reference in this standard. For dated references, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, parties to agreements based on this standard are encouraged to study whether the latest versions of these documents can be used. For undated references, the latest versions apply to this standard. GB/T5606.1 Cigarette sampling
YC/T5 General principles for batch sampling of tobacco leaves
YC/T31 Preparation and moisture determination of tobacco and tobacco products Oven method YC/T34 Determination of total alkaloids in tobacco and tobacco products Photometric method 3 Principle
Tobacco samples are extracted with water, and the total alkaloids (in terms of nicotine) in the extract react with p-aminobenzenesulfonic acid and cyanogen chloride, which is produced by the online reaction of potassium cyanide and chloramine T. The reaction product is measured by a colorimeter at 460nm. Note 1: Studies have shown that extraction with water and 5% acetic acid solution can obtain the same results. If total alkaloids and water-soluble sugars are analyzed simultaneously, it is recommended to use 5% acetic acid solution as the extraction agent.
4 Reagents
Use analytical grade reagents, and water should be distilled water or water of equivalent purity. 4.1 Brij 35 solution (polyethoxylated lauryl ether) Add 250g Brij35 to 1L water, heat and stir until dissolved. 4.2 Buffer solution A
Weigh 2.35g sodium chloride (NaCI) and 7.60g sodium borate (NazB,O,·10H,O), dissolve in water, then transfer to a 1L volumetric flask, add 1mL Brij35 (4.1), and dilute to 1L with distilled water. Filter with qualitative filter paper before use. 4.3 Buffer solution B
Weigh 26 g sodium dihydrogen phosphate (NazHPO,), 10.4 g citric acid [COH(COOH)(CH,COOH)2·H,O], 7 g p-aminobenzenesulfonic acid (NHzC,H,SO,H), dissolve in water, then transfer to a 1L volumetric flask, add 1 mL Brij35 (4.1), and dilute to 1 L with distilled water. Filter with qualitative filter paper before use.
4.4 Chloramine T solution (N-amino-4-methylbenzenesulfamide sodium salt) [CH,CH,SO2N(Na)CI·3H,O]Weigh 8.65 g chloramine T, dissolve in water, then transfer to a 500mL volumetric flask, and dilute to the mark with water. Filter with qualitative filter paper before use.
4.5 Cyanide antidote A
Weigh 1 citric acid [COH(COOH)(CH,COOH)z·H2O], 10 g ferrous sulfate (FeSO·7H,O), dissolve in water, dilute to 1L
4.6 Cyanide antidote B
Weigh 10 g sodium carbonate (Na,CO,), dissolve in water, dilute to 1L. 4.7 Potassium cyanide solution
Potassium cyanide is highly toxic, so be careful when handling!
In a fume hood, weigh 2 g potassium cyanide in a 1L beaker, add 500 mL water, stir until dissolved, and store in a brown bottle. 4.8 Standard solution
4.8.1 Determine the purity of nicotine or nicotine salt according to YC/T34. 4.8.2 Reserve solution: Weigh an appropriate amount of nicotine or nicotine salt into a 250mL volumetric flask, accurate to 0.0001g, dissolve in water, and dilute to the mark. The nicotine content of this solution should be around 1.6mg/mL. Store in a refrigerator. This solution should be prepared once a month. 4.8.3 Working standard solution: Prepare at least 5 working standard solutions from the reserve solution with water. The purity of nicotine or nicotine salt should be considered when calculating the concentration of the working standard solution, and its concentration range should cover the expected sample content 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, consisting of the following parts (see Figure 1): sampler;
a proportional pump;
dialyzer;
a heating tank;
spiral tube;
colorimeter, equipped with 460nm filter;
recorder or other suitable data processing device. /(0.32 mUmin), air
1 skin solution
305mm(12 inches)
460 nm filter
2. 0mm×15mm flow cell
white/white (0. 60 mL/min), buffer solution A orange/white (0. 23mL/min), sample
black/black (0. 32 mL/min), air
red/red (0. 80 mL/min ), buffer solution B orange/green (0. 10 mLmin ), KCN
1/green (0. 10 mL/min ), chloramine T
gray/gray (1. 00 mL/min ), antidote solution A gray/gray (1. 00 mL/min)), cooked venom solution B yellow/yellow (1.40 mL/min ) water
Figure 1 Diagram of the total alkaloid determination pipeline
5.2 Balance, sensitivity 0.000 1g.
5.3 Oscillator.
6 Analysis steps
6.1 Sampling
Extract samples according to GB/T5606.1 or YC/T5. 6.2 Prepare samples according to YC/T31 and determine the moisture content. YC/T 160—2002
6.3 Weigh 0.25g of sample into a 50mL ground-mouth conical flask, accurate to 0.0001g, add 25mL of water, cover with a stopper, and extract on an oscillator for 30min.
6.4 Filter with qualitative filter paper, discard the first few milliliters of filtrate, and collect the subsequent filtrate for analysis. 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 Calculation and expression of results
7.1 Calculation of total alkaloids
The content of total alkaloids on a dry basis is obtained by formula (1): Total alkaloids (%) =
mx(1=W)
W——The water content of the sample.
7. 2 Expression of results
The average value of two measurements is taken as the measurement result, and the result is accurate to 0.01%. 8 Precision
The difference in the absolute value of two parallel measurement results should not be greater than 0.05%. (1)
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