This standard specifies the determination method of dichloromethane extract in leather. This standard is applicable to all types of leather. QB/T 2718-2005 Leather chemical test Determination of dichloromethane extract QB/T2718-2005 Standard download decompression password: www.bzxz.net

ICS 59. 140
Classification number: Y45
Registration number: 15770-2005
Light Industry Standard of the People's Republic of China
QB/T 2718—2005
Replaces QB/T3812.13—1999
Chemical tests
Determination of dichloromethane extract
Leather-Chemical tests-
Determination of matter soiuble ln dichloromethane(ISO 4048 : 1977, Leather--Dctermination of matter soluble indichloromethane, MOD)
Issued on March 19, 2005
Implementation by National Development and Reform Commission of the People's Republic of China on September 1, 2005
This standard is a revision of QB/T 3812.13-1999 Determination of alkane extracts in leather - QB/T 2718-2005
This standard modifies and adopts [SO4048:1977 Determination of 4-dioxane in leather> (Lcathcr-Dcterminatio of maltcrsolublc dichloroncthanc), which is an international standard and the International Union of Leather Chemists (IULICs) standard C4. Based on the actual situation in my country, this standard has made the following technical modifications after adopting ISO 4048:1977: The explanatory content in the introduction was moved to 4 principles: The original ISO standards cited in "Normative reference documents" were rewritten as references to relevant Chinese standards: 7.1 and 7.2 in the original standard were merged
The content of 8 "Preparation of test specimens" in the original standard was adjusted to 7.2: For easier use, 8 was refined and divided into 8.1, 8.3, 8.3, 8.4, and 8.5: The requirements for calculation results were added in 9.1. This standard has also been edited as follows: In addition to the ISO standard foreword: The word "International Standard" is changed to "non-standard" and the decimal point "" is used instead of the decimal point "". The main changes of this standard QB/T3812.13-1999 are as follows: 2 "Standard Reference Documents" are added: 7 "Preparation for Sampling and Testing of Specimens" are added. This standard was proposed by the China Light Industry Federation. This standard was issued by the National Technical Committee for Standardization of Leather Industry (SAC/TC232) and drafted by: China Leather and Footwear Industry Research Institute. The main drafter of this standard: Yue Liguo. This standard was first issued on October 4, 1944. The original national standard GB4689.13-1984 was converted into the light industry standard QB/T3812.13-1999 in April 1999. This is the first revision. From the date of implementation, this standard replaces the light industry standard QB/T3812.13-1999 issued by the State Light Industry Department. Determination of methane extracts in leather. 3.
1 Scope
Determination of methane extracts in leather chemical tests This standard specifies the determination method of methane extracts in leather. This standard is applicable to various types of leather. 2 Normative references
QB/T2718-2005
The clauses in the engraved document become clauses of this standard through reference to the small standard. For all dated referenced documents, all subsequent revisions (excluding errata) and 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 edition shall apply to this standard: QH/T 2706-2005 Leather chemical test - Sampling locations for single and mechanical chromaticity tests (ISO 2418: 2002, MOD) Sampling quantity for complete sampling batches (ISO 2588: 1985, MOD) QB/T 2708-2005 Preparation of samples for leather chemical tests (ISO 4044: 1977, MOD) QB/T 2716-2005 5 Leather chemical test - Determination of water-soluble matter, water-soluble inorganic matter and water-soluble organic matter QD/T 2721-2015 3 Terms and definitions The following expressions and definitions are applicable to this standard.
Extraction
Oil and other soluble substances are extracted from the skin with dichloromethane. 4 Principle
The prepared skin sample is extracted with dichloromethane in reverse order, the solvent in the extract is evaporated, and the extract is dried at (102±2)°C and weighed.
Oil and similar substances cannot be completely extracted from the skin with organic solvents. Some of them are solubilized and some of them may be combined with the skin. On the other hand, solvents may dissolve non-fat substances such as sulfonates and fillers, both of which will affect the determination of the acid saponification value of oils.
The apparatus and procedures specified in this method are also applicable to extraction with solvents other than dichloromethane. If other solvents or solvent mixtures are used for other reasons, they should be stated in the test report. 5 Reagents and materials
Only analytically pure reagents can be used in the analytical process. 5.1 Dichloromethane, temperature 38 ℃ ~ 40 ℃, should be freshly heated and stored in a brown bottle, the brown bottle is placed on calcium butyl amide. Warning: Dichloromethane contains toxic substances, use with caution. Note: After dichloromethane has been stored for a long time, a test should be conducted to see if there is hydrochloric acid. Under dryness, add 0.1: nmA/. silver solution to 10mL of dichloromethane. If the nitric acid solution becomes turbid, the monochloromethane should be freshly evaporated and stored as specified in 5.1.
2; some dichloromethane that has been used for a month can still be used after recovery. 1
QB/T27182005
6 Apparatus
6, 1 system yield analyzer, including a density-controlled yield averaging bottle and a condenser. 6.2 A suitable size cylinder or medium for glass sink. 6.3 Drying, the temperature can be controlled within the range of (102±2)℃. Preparation of sampling and test specimens
7.1 Sampling
H If the relevant parties have special agreement, samples shall be drawn from the batch production according to the provisions of QR/T2708200, and samples shall be taken for determination of QR/T27H200. Other sampling shall be carried out according to the company or the cooperation. If the sampling cannot be carried out according to the standard, such as by direct contact, eye installation, etc., the test report shall be recorded in detail.
7. 2 Preparation of the sample
Follow the provisions of QH2716-2005
8 Procedure
8.1 Weigh 110-0.1% of the sample: press it evenly onto the filter paper or filter paper (6.2), and apply a thin layer of cotton wool (51) coated with fat on the surface of the sample.
8.2 Place two beads on the surface of the sample: the standard (6.1> is about (102+2)% Add 30 minutes and put it in a ten-pressure reactor and cool it. After burning, weigh it.
8.3 Take dimethylbenzene from the solvent continuously (Note 1). After the solvent is refluxed for 31 times, add dimethylbenzene to the flask containing only the collected product and evaporate it (2).
8.4 Fill the extract with 102_22 and dilute it with 6.34 solvent for 4 hours (if there are water droplets in front of the membrane, add 1~2 alcohol and put it in a ten-pressure reactor and cool it for 130 minutes and weigh it. 8.5 How to ignite ( 1h), cool and weigh the rust rate at least 3 times, until the two weighings differ by no more than 0.01 mA, or the total drying time exceeds 8 (see 3) www.bzxz.net
Note: The dimethyl pit can be used to mark the fetal pressure of the product, and the blood is only denser than other materials with a color of sediment. It proves that the carbon dioxide can be separated from the product by the following method; if a small amount of 7 stems are found, it can be sold: after a small change, it is put into the bottle under the mouth and used for thorough room After washing for a period of time, the extract is evaporated in the heat-generated solution, acetaldehyde is removed from the collected material, and the flame is removed in advance. The cola is ground and the sediment is analyzed by single-phase analysis. After combustion, the extract is taken out. Note 2: The extract can be analyzed by distillation to determine the content of free fatty acids in the extract. Note 3: After the extraction, the free fatty acids in the extract can be determined by QB/T272! 2005. The results show that the free fatty acids in the extract can be determined by QB/T272! 2005.1 Calculation
The effective dose (or other specified dose) of the substance is expressed as a mass fraction and the total value is expressed as a fraction according to formula (1): Quality (%) -
Where:
The quality of the sample is expressed as the required quantity (%)
The amount of the collected substance is expressed as grams (%)
The result is expressed as an average value with one decimal place, x100
Q/T2718—2005
9.2 Safety
In a reading room, the parallel effective doses determined by the operator are obtained, and the total value shall not exceed 0.2% of the original quality of the sample: 9.3 Reproducibility
In different experiments, the difference between the results of the measurements on the samples made by different operators shall not exceed 0.5% of the original sample. 10 Test report
The risk report should contain the following contents:
Number of this standard:
Sample name, number, integer,
Detailed information of the sample, whether the sampling is consistent with QB/T2706-2UU5 technology:
Characteristics of the floating agent:
Test station and its half mean (%):
Any special circumstances that may affect the test results: The differences between the actual operation and this standard.
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