GB/T 14924.10-2001 Determination of amino acids in compound feeds for experimental animals

This standard specifies the determination method of amino acids in compound feeds for experimental animals. This standard is applicable to the determination of amino acids in compound feeds and their raw materials for experimental animals such as mice, rats, rabbits, guinea pigs, hamsters, dogs and monkeys. GB/T 14924.10-2001 Determination of amino acids in compound feeds for experimental animals GB/T14924.10-2001 Standard download decompression password: www.bzxz.net

GB/T 14924.10wwW.bzxz.Net
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This standard is separated from GB14924-1994 "Complete Nutrient Feed for Laboratory Animals" to form an independent standard. This standard specifies the determination methods of three tryptophans in compound feeds for laboratory animals: the first method is high performance liquid chromatography; the second method is fluorescence spectrophotometry; the third method is spectrophotometry. The first method is the arbitration method. This standard and its supporting standards shall replace GB14924-1994 from the date of implementation.
This standard is proposed and managed by the Ministry of Science and Technology of the People's Republic of China. The drafting unit of this standard is the Chinese Society of Laboratory Animals. The main drafters of this standard are Zhang Yu, Zhou Ruihua, Jia Jianbin, Wang Guodong, Liu Sumei, Zheng Tao, and Liu Xiumei. This standard is interpreted by the Chinese Society of Laboratory Animals, the technical management unit entrusted by the Ministry of Science and Technology of the People's Republic of China. This standard was first issued in January 1994.
1 Scope
National Standard of the People's Republic of China
Laboratory animals
Formula feeds
Determination of amino acids
Laboratory animals-Formula feeds-Determination of amino acids This standard specifies the method for the determination of amino acids in formula feeds for laboratory animals. GB/T14924.10-2001
Replaces G13119241994
This standard applies to the determination of amino acids in formula feeds and their raw materials for laboratory animals such as mice, rats, rabbits, guinea pigs, hamsters, dogs and monkeys. 2 Cited standards
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision, and parties using this standard should explore the possibility of using the latest versions of the following standards. G3/T14965-1994 Determination of amino acids in food (G13/T15400-1994 Determination of tryptophan in feed Spectrophotometric method GB3/T182462000 Determination of amino acids in feed 3 Determination method
3.1 Determination of amino acids in compound feed
According to the relevant provisions of GB/T18246 and GB/T14965. 3.2 Determination of tryptophan in compound feed
3.2.1 The first method Determination of tryptophan
According to the provisions of GB/T15400-1994. 3.2.2 The second method Fluorescence spectrophotometric method
3.2.2.1 Principle
During the acid hydrolysis process of protein in feed, the tryptophan is easily hydrolyzed. This method uses alkaline water The natural carbon fluorescence of tryptophan can be directly measured by protein hydrolysis. In the protein hydrolyzate, only tryptophan and tyrosine can be detected with fluorescence. At pH 11, the fluorescence intensity of tryptophan is 100 times greater than that of tyrosine, and the fluorescence peaks of the two amino acids differ by more than 40nm. Based on this feature, the content of tryptophan can be detected in the presence of a large amount of tyrosine.
3.2.2.2 Reagents
3.2.2.2.1 Sodium hydroxide solution (5mol/l.): Dissolve 20g of sodium hydroxide with 0.5% soluble starch and make up to 100ml-, prepare before use.
3.2.2.2.2 Urea solution (4mol/l.): Adjust the pH to 11. 3.2.2.2.3 50% hydrochloric acid: Add 1 part of concentrated hydrochloric acid (super pure) to 1 part of double distilled water. 3. 2. 2. 2. 4
Bromothymol blue aqueous solution (0.5g/1): 0.1g bromothymol blue indicator, add 0.1mol/1 sodium hydroxide solution. Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China on August 29, 2001. 512
Implementation on May 1, 2002
GB/T 14924. 10.--2001
1.6ml..Prepare into an aqueous solution with a final concentration of 0.5g/L 3.2.2.2.5 High purity nitrogen (content 99.99%). 3.2.2.2.6 Octanol toluene solution: contains 1% octanol. 3.2.2.2.7 Tryptophan standard preparation solution (1mg/ml): Accurately weigh 100mg of tryptophan. Dissolve it in 0.005mol/l sodium oxynitride solution and make up to 100ml.
3.2.2.2.8 Tryptophan standard application solution (0.2mg /ml): Accurately pipette 10ml of tryptophan standard stock solution into a 50ml volumetric flask and dilute to the mark with water. Prepare it before use. 3.2.2.3 Instruments
Fluorescence spectrophotometer, vacuum evaporator, polytetrafluoroethylene tube (5mL). 3.2.2.4 Sample treatment
After the plant sample is crushed, store it in a sample bottle for later use. 3.2.2.5 Analysis steps
3.2.2.5.1 Sample preparation: Accurately weigh a sample containing about 5mg of crude protein and place it in a polytetrafluoroethylene tube. Add 1ml of sodium hydroxide solution containing 5mol/I of soluble starch, add a drop of octanol, and place the sample tube in a container. Add ice and salt to the outside of the container to cool it down, and evacuate it to less than 1.3kFa (10mmHg) for 15min. Fill it with nitrogen and then reduce the pressure, repeat three times. Seal the nitrogen-filled and reduced-pressure container, put it in a 110C oven, and hydrolyze the sample with alkali for 22h. After the sample is cooled, add 0.7mL of (1:1) hydrochloric acid, wash the sample with deionized water into a 25ml volumetric flask, adjust the pH to neutral with bromothymol blue as an indicator, and dilute to the mark with deionized water. 3.2.2.5.2 Determination: Take 1ml of the sample solution, add 4mol/1. urea solution (pHl1) to dilute to 10ml in a 10ml stoppered graduated test tube. Measure the fluorescence intensity at an excitation wavelength of 280nm and an emission wavelength of 360nm, and find out the tryptophan content in the sample from the standard curve.
3.2.2.5.3 Drawing of the standard curve: Take 0.00.5, 1.5.2.0ml of the tryptophan standard application solution in two polytetrafluoroethylene test tubes, and add 1\ to the tryptophan content of 0.0, 0.1, 0.3, and 0.4mg. Perform alkaline hydrolysis in the same way as sample preparation (3.3.1.5.1). Use the measured fluorescence intensity of the standard series as the ordinate and the tryptophan standard content as the abscissa to draw a standard curve. 3.2.2.6 Calculation
See Wu (1).
Tryptophan content, mg/100g;
Check the tryptophan content from the standard curve, mg;;, dilution factor;
m-sample mass.g.
3.2.2.7 Allowable error
Relative standard deviation of repeated determinations in the room ≤10%. 3.2.3 Method III spectrophotometry
Perform in accordance with GB/T15400.
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