GB/T 5009.124-2003 Determination of amino acids in foods

This standard specifies the method for determining amino acids in food using an automatic amino acid analyzer. This standard is applicable to the determination of 16 amino acids in food, including aspartic acid, threonine, serine, glutamic acid, proline, glycine, alanine, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, histidine, lysine and arginine. Its minimum detection limit is 10pmol. This standard is not applicable to the determination of amino acids in fruits, vegetables, beverages and starchy foods with low protein content. GB/T 5009.124-2003 Determination of amino acids in food GB/T5009.124-2003 standard download decompression password: www.bzxz.net

67,040
National Standard of the People's Republic of China
GB/T5009.124--2003
Replaced GB/T14965-1994
Determination of amino acids in food
foods2003-08-11 Issued
Ministry of Health of the People's Republic of China
Standardization Administration of the People's Republic of China
Implementation on January 1, 2004Www.bzxZ.net
GH/T5009.124—2003
This standard replaces GB/T14665-1994 Determination of amino groups in foods Technical standard Compared with GB/T1496E-994, the main changes are as follows: The Chinese name of the standard is adopted and the Chinese name of the standard is changed to Determination of amino groups in foods GH/T2000-4-20014 Rules for writing standards Part 4: Chemical analysis methods 3 The structure of the original standard is modified.
This standard is issued by the Ministry of Health of the People's Republic of China and is under the jurisdiction of the Institute of Nutrition and Food Hygiene, Chinese Academy of Preventive Medicine. The main drafters of this standard are Jia Jianbin and Song He. The source standard was first released in 1999, and this is the first time. 1.5
Determination of amino acids in food
This standard specifies the method for determining amino acids in food using an automatic standard acid analyzer, GB/T 5009.124-2003
This standard is applicable to the determination of aspartic acid, arginine, endogenous amino acids, glutamic acid, ceramide, arginine, isothiocyanate, isothiocyanate, hydroxyethyl ester, hydroxypropyl ester, histidine, arginine and other amino acids in food. The minimum detection limit is 20 pm
This standard is not suitable for the determination of amino acids in fruits, vegetables, beverages and powders with low protein content. 2 Principle
The protein in the food is converted into dichloromethane by hydrochloric acid and water, and then separated by amino acid analyzer and added to the leucine solution to produce a color reaction, and then the content of hydrogen radicals is determined by spectrophotometer colorimetry. 3 Trial
3.1 bottle of water: 3.26 mul/L Heat: Mix dilute hydrochloric acid with water 1 + 1. 3.3 Benzoic acid: Distill and add 3,4 (5.0025ml/L) mixed with 1% benzoic acid standard solution (the manufacturer provides 3.5). 3.5. Sodium citrate solution with pH 2.2: weigh 19g sodium citrate (NaCFLO, 2H2O) and 15.5mL concentrated hydrochloric acid, add 1mL concentrated hydrochloric acid or 506/mL sodium hydroxide to 2.23. 5.23.3 Sodium citrate solution: take 2mL concentrated sodium citrate, dilute with 10mL water, and adjust the pH to 3.3 with 560g/mL sodium hydroxide. 3.5.3 Sodium citrate solution with pH 4.0: weigh 1.6g sodium hygroscopic acid and 9mL distilled water to 1mL 00CmL, adjust the pH to 4.2 with concentrated sodium hydroxide solution (5M). 3.5.4 PF13.3 sodium thiocyanate solution: Take 19.63 g sodium citrate and 46.8 g sodium oxide (superior grade) and dilute to 100 mL with water. Adjust the pH to 9.4 with concentrated or 500 g/mL hydroxide. 3.6 Tris solution
3.6. pH 1.2 lithium thiocyanate solution, weigh 55 mL lithium hydroxide (superior grade) and add 27 mL water to 100 mL, adjust the pH to 5.2 with hydrochloric acid or 500 g/mL sodium hydroxide solution. 3.6.2 Pre-trione solution, take 15 mL dimethyl sulfoxide (CH2SO4) and 50 mL acetic acid solution and add 4% hydrated oxalool [C2H2O3]. 2 The reduction reaction (CuO, 2H, O) is completely dissolved, 3.7 The commercial purity is 59%.
3.8 Cooling, according to 1-3, contains: 4 Promoters and equipment
4.1 Vacuum recorder:
4.2 Constant temperature drying oven.
4,3 Hydrolysis tube, resistant glass tube or better glass with end cap, volume 2mL~2mL. Rinse thoroughly with deionized water and dry. 4.4 Vacuum blaster (Monkey two).
CB/T 5009.124—2003
4.5 Automatic analysis of amino acids.
5 Sample processing
The sample is beaten into a slurry by a homogenizer (the sample should be concentrated as much as possible) and stored in a low-temperature refrigerator for medium freezing. When used for analysis, it will be thawed quickly before use.
Analysis steps
6.1 Sample weighing
Accurately weigh the sample with good quantitative homogeneity, such as milk powder, etc., and determine the exact value of C, 000g (make the sample egg mouth The quality content is in the range of 10m-20m1%! For samples with poor homogeneity such as fresh meat, the weighing amount can be appropriately increased to reduce the error. Dilute before measurement. Put the weighed sample in the hydrolysis tube.
6.2 buckets
Add ml/1. Hydrochloric acid in the water) 1 [depending on the quality content of the sample): the sample with the highest water content (such as milk; can add an equal volume of concentrated hydrochloric acid, add a drop of freshly evaporated test, the hydrolysis tube can be stored in the freezer, frozen for ?min~min, and then connected to the exhaust pipe of the vacuum system, vacuum (close to 0Pa). Then fill it with high-purity hydrogen: vacuum fill it with chlorine, after one time, seal it or tighten the screws under the hydrogen filling state, and put the sealed [1] hydrolysis tube in a constant temperature drying box at 1107±17, hydrolyze for 22h, and take it out.
Take 100ml of hydrolyzate. After filtering the hydrolyzate, rinse the hydrolyzate tube with carbo-ion water several times, transfer the hydrolyzate to 53ml. Add 20ml of water to the bottle and make up to volume. Take 1ml of the solution from the warm water. Put it into a desiccator at 40-ECC and dry it. Use 1ml of water to keep the solution and then add 1ml of water to dry it again. Repeat this process twice. After evaporation, dissolve it in 11l of EH2O2 buffer for instrument determination. 7 Determination
Accurately pipette 0.2J of the mixed amino acid standard and condense it to 1ml with pH 2.2 condensate. The concentration of this standard solution is 5.0)nl/50x1. It is used as the amino acid standard for the machine determination. The amino acid content of the sample standard solution is determined by the external standard method using a broad-base acid automatic analyzer.
8 Calculation of results
As follows:
XFxVXM
nx100-·×100
Wherein:
X is the nitrogen content of the sample, in grams per hundred grams (R/100); RC is the basic content of the sample test solution, in milliliters per 50 microliters (mo./59L); F is the dilution efficiency of the sample;
V.-the volume of the sample after hydrolysis, in milliliters (ml.); M
is the mass of the sample, in gramsNumber of cases, sixteen amino acid molecules; aspartic acid: 133.1; threonine: 119.1; serine: 05.1; glutamic acid: 117.1; proline: 115.1; 75.1; alanine: 89.1; methionine: 117.2; isoleucine: 131.2; oxalic acid: 131.2; alanine: 181.24; histidine: 155.3; amino acids: 146.21; sugars: 14,218
6B/T 5009.1242003
The calculation result is expressed as: the test nitrogen content is less than 1.0/1, retain two significant figures, the total inventory is 1.00%/1CC, retain three significant figures,
precision
the single pair difference obtained under the recombinant condition shall not exceed 12% of the average value, 10 standard chart
standard chart see chart
period sequence
aspartic acid
yellow mouse
selection time/mnia
Wang Fengming point
study function
propionic acid
production
production state/min
25, 76
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