This standard specifies the first method for determining the unsaponifiable matter content of animal and vegetable fats and oils by ether extraction. This standard applies to all fats and oils. It does not apply to waxes. Moreover, only approximate results can be obtained for fats and oils with high unsaponifiable matter content, such as marine animal fats and oils. When climatic conditions or environment do not allow the use of ether, the hexane method can be used. GB/T 5535.1-1998 Determination of unsaponifiable matter in animal and vegetable fats and oils Part 1: Ether extraction method (first method) GB/T5535.1-1998 Standard download decompression password: www.bzxz.net

GB/T5535.1—1998
This standard is a revision of GB5535—1985 “Determination of unsaponifiable matter in vegetable oils and fats” based on the international standard IS03596-1:1988 “Determination of unsaponifiable matter in animal and vegetable oils and fats Part 1: Ether extraction method (first method)”. It is equivalent to the international standard in terms of technical content, and is written in accordance with the requirements of GB/T1.1—1993 “Guidelines for standardization work Unit 1: Rules for drafting and expressing standards Part 1: Basic provisions for standard writing”. This standard was proposed by the Ministry of Domestic Trade of the People’s Republic of China. The drafting unit of this standard: Cereal Oil Chemistry Research Institute of the Ministry of Domestic Trade. The main drafters of this standard: Hao Xicheng, Liu Jing, Ying Shanhong. ISO Foreword
ISO (International Organization for Standardization) is a worldwide federation composed of national standardization bodies (ISO member bodies). The work of formulating international standards is usually carried out by ISO’s technical committees. Each member body has the right to participate in the work of a committee if it is interested in a standard project established by a technical committee. International organizations (official or unofficial) in contact with ISO may also participate in the work. In the field of electrotechnical standardization, ISO maintains a close cooperative relationship with the International Electrotechnical Commission (IEC). The draft international standard adopted by the technical committee must be submitted to the member bodies for approval before it is accepted as an international standard by the ISO committee. An international standard must be approved as a formal ISO standard by at least 75% of the member bodies voting.
International Standard IS03596-1 was developed by IS0/TC34 Agricultural Food Technical Committee. The general title of IS03596 is "Animal and Vegetable Fats and Oils-Determination of Unsaponifiable Matter" and consists of the following parts: Part 1: Ether Extraction Method (Benchmark Method) Part 2: Hexane Extraction Rapid Method
Appendix A of this part of IS03596 is for reference only. Approved by the State Administration of Quality and Technical Supervision on May 8, 1998 and implemented on December 1, 1998
GB/T 5535.1—1998
National Standard of the People's Republic of China
Determination of unsaponifiable matter in animal and vegetable fats and oils
Part 1: Rapid method using ether extraction
Animal and vegetable fats and oilsDetermination of unsaponifiable matterPart 1:Method using diethyl ether extraction (Reference method)GB/T5535.1—1998
eqvISo
3596-1:1988
Replaces GB5535-85
1Scope
This standard specifies the first method for determining the unsaponifiable matter content of animal and vegetable fats and oils by ether extraction. This standard applies to all fats and oils. It does not apply to waxes. Moreover, only approximate results can be obtained for oils with high unsaponifiable matter content, such as marine animal fats. When climatic conditions or environment do not allow the use of ether, the hexane method can be used. 2 Referenced standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When the standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest version of the following standards. GB/T15687-1995 Preparation of oil and fat samples (eqvIS0661: 1989) 3 Definitions
This standard adopts the following definitions.
Unsaponifiable matter: All products of the sample after saponification with potassium hydroxide are extracted with a specific solvent under the operating conditions specified in this standard, and the residue after evaporation of the solvent and drying. Expressed as mass percentage.
Note: Unsaponifiable matter includes natural lipids, such as alcohol, high molecular weight fatty alcohol and olefin compounds. In addition, any non-volatile organic impurities (such as mineral oil) extracted by solvent at 103°C may also be present.
4 Principle
Fats and potassium hydroxide ethanol solution are saponified under boiling and reflux, and unsaponifiable matter is extracted from the soap solution with ether. The solvent is evaporated and the residue is dried and weighed. 5 Reagents
The reagents listed in this standard are all analytically pure, and the water is distilled water. 5.1 Ether (HG3-1002): does not contain peroxides and residues. 5.2 Acetone.
Approved by the State Administration of Quality and Technical Supervision on May 8, 1998 and implemented on December 1, 1998
GB/T5535.1-1998
5.3 Potassium hydroxide (GB2306) ethanol solution: c(KOH)~1mo1/L. Dissolve 60g potassium hydroxide in 50mL water and dilute to 1000mL with 95% (V/V) ethanol. The solution should be colorless or light yellow.
5.3.1 Potassium hydroxide ethanol solution: c(KOH)~0.5mol/L. 5.4 Potassium hydroxide standard solution: c(KOH)~0.1mol/L (prepared with 95% ethanol) The exact concentration of the solution must be known before use and should be calibrated. Use a solution prepared at least five days ago, transfer the clear solution to a brown glass bottle for storage, and seal it with a rubber stopper. The solution should be colorless or light yellow. 5.5 Phenol (GB10729) indicator solution: 10g/L 95% ethanol solution. 6 Instruments
6.1 Round bottom flask: 250mL round bottom flask with standard ground mouth. 6.2 Reflux condenser: Match the ground mouth of the flask (6.1). 6.3500mL separatory funnel, preferably with a polytetrafluoroethylene piston and stopper. 6.4 Water bath
6.5 Electric oven or vacuum drying apparatus capable of maintaining (103±2)℃, such as a rotary evaporator or similar apparatus.
7 Sample preparation
Perform according to GB/T15687.
8 Analysis steps
8.1 Sample
Weigh about 5g of sample (accurate to 0.01g) and place it in a 250mL flask (6.1). 8.2 Saponification
Add 50mL of potassium hydroxide solution (5.3) and some zeolite. Connect the flask to the reflux condenser (6.2) and boil and reflux for 1h. Stop heating, add 100mL of water from the top of the reflux tube and shake. 8.3 Extraction of unsaponifiable matter
After cooling, transfer the solution to a 500mL separatory funnel (6.3). Rinse the flask and zeolite with 100mL of ether (5.1) several times, and pour the rinse solution into the separatory funnel. Cover the stopper and shake vigorously for 1 minute. Invert the separatory funnel and carefully open the piston to release the internal pressure intermittently. After standing and separating the layers, try to put the lower soap solution into the second separatory funnel.
Note: If an emulsion is formed, add a small amount of ethanol or concentrated potassium hydroxide or sodium chloride to break the emulsion. Extract the ethanol soap water solution twice more, using 100mL of ether each time, and use the same method. Collect the three ether extracts and put them into a separatory funnel filled with 40mL of water. 8.4 Washing of ether extract
Gently rotate the separatory funnel containing the mixture of 40mL of water and extract. Note: Vigorous shaking will form an emulsion at this stage. After complete separation, discard the lower water layer. Wash the ether solution twice or more with 40 mL of water each time and shake vigorously. After the layers are separated, discard the lower water layer. When discharging the washing liquid, keep 2 mL. Then rotate the separatory funnel along its axis and wait for a few minutes to continue collecting the water layer. Discard the water layer and close the piston when the ether solution reaches the piston mouth. Wash the solution twice with 40 mL of potassium hydroxide solution (5.3.1) and then with 40 mL of water. Finally, wash with 40 mL of water twice or more according to the above method. Continue washing with water until the washing liquid no longer turns pink after adding a drop of phenolic acid solution (5.5). 8.5 Evaporation of solvent
Approved by the State Administration of Quality and Technical Supervision on May 8, 1998, and implemented on December 1, 1998
GB/T5535.1-1998
Transfer the ether solution quantitatively in small amounts through the upper opening of the separatory funnel to a 250mL flask (6.1) that has been dried in an oven (6.5) at (103±2)°C in advance, and weigh after cooling to an accuracy of 0.1mg. Recover the solvent by distillation in a boiling water bath (6.4). Add 5mL of acetone and evaporate the volatile solvent completely under a gentle air flow. 8.6 Drying and determination of residue
Dry the residue in an oven at (103±2)°C for 15min, with the flask placed horizontally. Cool in a desiccator and weigh to an accuracy of 0.1mg. Repeat the above method until the mass weighed twice does not exceed 1.5mg. If the weight is not constant after three dryings, the unsaponifiable matter may be contaminated and needs to be re-measured. When the weight of the residue is corrected by the content of free fatty acids, the weighed residue is dissolved in 4 ml of ether and then 20 ml of pre-neutralized phenol crisp indicator solution (5.3) Ethanol with a pale pink color. Titrate with potassium hydroxide solution (5.4) to the same final color. Calculate the mass of free fatty acids with oleic acid and use this to correct the mass of the residue (see Chapter 9). 8.7 Number of determinations
Two determinations are required for the same sample.
8.8 Blank test
Use the same procedure and the same amount of all reagents, but do not add the sample. If the residue exceeds 1.5 mg, the reagents and methods need to be improved.
9 Calculation of results
The unsaponifiable matter content is expressed as a percentage of the mass of the sample and calculated according to formula (1): Unsaponifiable matter (%) = m-m2-m3×100…
Where: mo
The mass of the sample, g;
The mass of the residue, g;
The mass of the blank residue, g;
The mass of free fatty acids, equal to 0.28Vc, g; -The volume of the standard potassium hydroxide ethanol solution, mL; The exact concentration of the potassium hydroxide ethanol standard solution, mo1/L. The arithmetic mean of the two determinations is used as the result. 10 Test report
The test report should specify the use of the results obtained. It should also describe any method not specified in this standard and any operational details that may affect the results. The test report should include complete information required for sample identification. Approved by the State Administration of Quality and Technical Supervision on May 8, 1998 and implemented on December 1, 1998
Approved by the State Administration of Quality and Technical Supervision on May 8, 1998 and implemented on December 1, 1998
GB/T5535.1-1998 on May 8, 1998bZxz.net
Implemented on December 1, 1998
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