Some standard content:
YC/T165—2D03
This standard is recommended to be revised and adopted TS06488-19974 Tobacco—Determination of Moisture Content—Part 1, Carlsberg Method 36 (Yanwen Co., Ltd.), and this standard is recommended to be drafted again based on TS06485-1,1997. Taking into account my country's national conditions, this standard has been revised quickly when adopting international standards. These technical differences are marked in the blank space of the terms they are in. In Appendix A, the technical differences and common reasons are listed for reference. For ease of use, the following editorial modifications have been made to this standard ISG48.1:1997: \1S04874191\\1S5725-2:1994\ is changed to \YC, T5\ and \G/TG379\. In addition to the foreword of 150641, 1997, Appendix A of this standard is an editorial appendix. Www.bzxZ.net
This standard was proposed by the State Tobacco Monopoly Administration
This standard was drafted by the National Tobacco Standardization Technical Committee (T1). The drafting unit of this standard: Traditional Chinese Medicine and Tobacco Standardization Research Center: The main drafters of this standard are: Pan Zeng, Ma Ming, Zheng He, 1 Scope
Determination of moisture content in tobacco: Karl Fischer method
This standard specifies the determination method of moisture content in tobacco with standard analysis. This standard is applicable to finished tobacco.
2 Normative references
Karl Fischer method:
YC/I 165--2003
The following documents have become the terms of this standard through the application of this agreement. The dated application documents are not applicable to this standard. However, all the revisions (excluding the contents of the revisions) or revisions that accompany this standard are not applicable to this standard. However, the parties to the agreement on this standard have studied whether the latest versions of these independent documents can be used. For any undated referenced documents, the latest version shall apply to this standard. YCT5 General principles for batch sampling of tobacco
YC/T31-10 Preparation and moisture content determination of tobacco and tobacco product samples Oven method 9 Terms and definitions
The following terms and definitions apply to this standard. 3.1
water content of tnhaccn
Moisture content of tobacco
The moisture content of tobacco is measured by using methyl ether. 3.2
Unflavored tobacco on cast tobacco baceo
This is the tobacco that has been scented or selected.
4 Principle
If anhydrous methyl ether is added to the bale sample and collected, the sample is filtered out and the moisture content of the sample is determined by titrating it with Karl Fischer's reagent.
Carl Fischer's reagent can react with iodine, sodium dioxide, pyridine and methyl ether in the sample in a quantitative manner. The reaction formula is as follows: H,O+SO+I3C,H.N+2C.HN-HI+CHNS C, INSO-GOH, NOSOI
5 Test
Use analytical grade test lubricant, water should be distilled water or water of equivalent purity: 5.1 Karl Fischer reagent: its absolute value is about 2mg/L~5mR/nL..5.2 Methanol: analytical grade, water content less than 0.05% dry weight fraction. 5.3 Activated silica, used as filling agent. 6 Apparatus
The glassware used should be heated at (105-5) for two hours and placed in a sealed desiccator to cool for a month. 6.1 Karl Fischer moisture analyzer: 6.-.1 to 6.1.5 Group sensor: 6.1.1 Hourly electrical quantity measuring device.
6. 1.2 Platinum telegraph.
YC/T165—2003
6.1.3 Moisture agitator.
6.1.4 Reaction bottle,
6.1.5 Titration, alcohol and Karl Fischer reagent. 6.2 Mechanical carbon nova, perturbation frequency 155 times/umin. 6.3 Pneumatic syringe, 0T
6.4 Single scale weighing tube. 1cm, 20mL.
6.5 Conical flask. 250mL. 500mL.
6.6 Flood tank (1C5 ± 5).
Standardization of Karl Fischer reagent
7.1 Titration
Add enough methanol (5.2) to the reaction mixture (6.1.4) to remove the end of the electrode. Titrate the water content in methanol by Karl Fischer titration test (5.1) to the end point.
Correction: The band lubrication is carried out in this way. When the concentration of the reactant exceeds a certain amount, the result will be: the plate electrode is still wrong. Sometimes this will help the concentration of methanol to be gradually reduced to the level below which it can be effectively carried out, and produce precipitation, making the lubrication station inaccurate. The experience of the report + should be discussed to expel all the body fluids in the anti-world, lift up and re-inject, and use a micro-single-filament syringe (6.31) to suck out 21.0% water. To ensure that there is no air in the syringe during injection, gently tap the syringe to move the air pool to the needle. Then move it vertically to 205/scale, quickly wipe the needle with selected paper, and carefully inject the water into the reaction energy. Be careful not to put the water into the broken bottle. There must be water leakage on the outer tip. The needle tip should be turned to touch the surface to let the water fall into the body. Lubricate the reagent (5.1) of Calfil, and verify the application. Volume of test sample consumed: Repeat the titration. If the deviation of the two titrations does not exceed 30 L, calculate the average titration volume. The titration of the test sample should be determined before each test. 7.2 Calculation of Titer
The titration degree of the test sample is given by the formula (): E
Where
E: The titration width of the test sample, in grams per milliliter (mR/mL). - The mass of the added substance, in grams (ng)... The average volume of the test sample consumed, in milliliter (mR)). 8 Test steps
8.1 Sampling
Prepare the sample according to YC/T=sampling. 8.2 Preparation of test sample
8.2.1 Take 100 g of the sample from the sample prepared in accordance with 6.1 of YC/T3_-1996. Place it in a dimensional bottle, weigh it accurately to 0.81, and place the sample in the dimensional bottle. Add 25 nmol, open the seal, and discharge 30 in. on a micrometer with a pumping frequency of 155 times/min.
8.2.2 If the sample is sufficient, the test column can be reduced to at least 3.3. Add at least 5 ml of the sample to the dimensional bottle. 8.2.3 Under unusual conditions, for the determination of the sample and the content of the sample, the sampling time of 10 min is not enough. Add 50 ml of the sample in a dimensional bottle, and the sampling time is reduced by 1 until a constant result is obtained. The difference between the two calculated results of the same extraction is not greater than 3.3% by mass fraction. 8.3 Determination of water content of the sample
8.3.1 Preparation of the agreed method
YC/T165-2003
Prepare the instrument according to the requirements of the end use. Add the promoter methanol (5.2) to the reaction chamber (61,4) so that the front of the double platinum electrode is completely immersed during stirring. Use the Karl Fischer reagent to titrate the volume of the titration tube to the end point. 8.3.2 Empty test
Pipette 250ml of methanol (5.2) into a 500mL conical flask. Use a single-scale pipette (6.4) to take 2mL of methanol from the conical flask to the reaction flask. Use Karl Fischer titration to determine the end point and record the volume of the consumed reagent. Repeat the determination. If the deviation of the two determinations does not exceed 0.0ml, take the arithmetic mean of the titration volumes. Blank value is calculated by formula (2):
Where:
V, the volume of the sample used for the blank test, in milliliters (mL),
The volume of the sample in the aliquot, in liters (mL), 8.3.3 Determination
Pipette 1 mL of the sample and add it immediately to the reaction bottle. Record the volume of the reagent used. Re-calculate the water content. If the difference between the two values is not greater than 0.3 of the volume of the titration, the average value of the result is calculated by the slope factor. The result is as follows:
The moisture content of the sample is calculated by formula (3): (BXV) × EX × 100
Where:
The percentage of moisture in the sample:
The volume of Karl Fischer reagent consumed in the titration, in milliliters (mL);
The volume of the sample extract added to the flask, in milliliters (ml);
The concentration of Karl Fischer reagent, in grams per milliliter (m/mL): The total volume of the sample extract, in milliliters (ml); The mass of the ground-filtered sample, in grams (mg). The results are expressed with an accuracy of 0.1%.
10 Reproducibility and reproducibility
An international collaborative study was conducted on the reproducibility (r) and reproducibility (R) of this standard. A total of 15 laboratories participated in the collaborative study, and two batches of tobacco leaves with different moisture contents were used in the test. Each batch consisted of five boxes, and each box of leaves was measured under reproducible conditions. The reproducibility and reproducibility of the method were determined in accordance with CE/T63. The data analysis and evaluation are shown in Table 1
Table 1 Data analysis and evaluation
Moisture level value (two 5 laboratories)
Reproducibility value*
The values given in Table 1 should be considered as the average value obtained by the calculation of 15 laboratories. In this paper, the reproducibility and reproducibility of the new density test method of GB/6379 (standard test method) were evaluated? 3
YC/T165—2D03
Acid test report
The test report shall state the method of use and the results obtained, and shall also indicate the operating conditions specified in this standard, the conditions that are considered optional, and the various conditions that affect the results. The test report shall include all design requirements for the evaluation of the sample. Attached (informative appendix)
Comparison table A1 of this standard and IS064BB-1:1997 shows the technical differences between this standard and IS06498-1:1997 and their advantages. 1. Technical differences between this standard and [506488-1:1997] and their reasons. This standard is divided into 4 articles according to the technical differences, so it adds ten "common analysis" standards, quotes the industry standards that adopt international standards, and quotes Y/T for routine sample preparation for ISO618119775 test stand-end device - single mother room transfer tube and 1503696:1 987 The definition and test method 3 of this standard for laboratory use are chemical detection methods. This standard is no longer a normative reference document for this standard. The amount of water in the Karl Fischer test is determined by the modified 21.. of IS>64:9. The single product quantity specified in [85488-1:1997 is modified. The international standard YC/T165--2003 does not specify the sample state. In order to adapt to the situation in my country, this standard is calibrated with the sample in 5.1 of YC/T31-1395. The sample is made with the standard 4, the operation error is reduced, and the tooth droplet scale is used as an alternative. The operation error is reduced to ensure that the other kidneys are simple and stable.
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