QB/T 5189-2017�-polyglutamic acid (English PDF)

6.2 Sensory inspection

At room temperature and no direct sunlight, take the specimen and place it in a clean white porcelain plate; perform the visual inspection.

6.3 Content of gamma-polyglutamic acid

6.3.1 Summary of method

The sodium sulfate solution is used as the mobile phase, to detect the ultraviolet absorption values of gamma-polyglutamic acid standard solutions of different contents.

The content of polyglutamic acid is determined by high performance liquid chromatography.

6.3.2 Reagents and materials

6.3.2.1 Water: Grade I water in GB/T 6682.

6.3.2.2 Anhydrous sodium sulfate: chromatographically pure.

6.3.2.3 Sodium sulfate solution (0.3 mol/L)

Weigh 42.6 g of anhydrous sodium sulfate; use water to dissolve it to make its volume reach to 1 L; use acetic acid to adjust the pH to 4.0; use with microporous membrane filter which has a pore size of 0.22 µm to filter it.

Ultrasonically degas it for 15 min.

6.3.2.4 gamma-polyglutamic acid standard: content (on a dry basis) >= 99.0%.

Note: Select polyglutamic acid standards with suitable average molecular weight range according to the product.

6.3.2.5 Standard stock solution of gamma-polyglutamic acid (10.0 mg/mL)

Weigh out 1.000 g of gamma-polyglutamic acid; use mobile phase to dissolve it and make its volume reach to 100 mL. The shelf life is 1 week at 4 °C.

6.3.2.6 Standard working solution of gamma-polyglutamic acid (1.0 mg/mL)

Pipette 10.0 mL of gamma-polyglutamic acid standard stock solution into a 100 mL volumetric flask; make its volume reach to 100 mL. This standard solution shall be prepared before use.

6.3.3 Equipment

Laboratory and the following instruments are applicable to this standard.

6.6.2 Reagents and materials

6.6.2.1 Water: Grade I water in GB/T 6682.

6.6.2.2 Anhydrous sodium sulfate: Chromatographically pure.

6.6.2.3 Sodium sulfate solution: 0.3 mol/L

Weigh 42.6 g of anhydrous sodium sulfate; dissolve and make its volume reach to 1 L; use acetic acid to adjust the pH to 4.0; use a microporous filter which has a pore size 0.22 µm to filter it; ultrasonically degas it for 15 min.

6. 6.2.4 Dextran standards: Chromatographically pure, which has a molecular weight of 5900 u; 11800 u; 22800 u; 47300 u; 112000 u; 212000 u; 404000 u;

788000 u, respectively.

6.6.2.5 Dextran standard solution

Use dextran standards as molecular weight standards. Respectively weigh 8 kinds of chromatographic pure dextran standards of different molecular weights, each 0.05 g. Dissolve it. Transfer it into a 50 mL volumetric flask to make it reach the volume.

6.6.3 Equipment

Laboratory and the following instruments are applicable to this standard.

High performance liquid chromatography: Equipped with a refractive index detector.

6.6.4 Chromatographic reference conditions

6.6.4.1 Chromatographic column: Gel chromatography column (7.8 mm x 300

mm, or a gel chromatography column with equivalent effect and specifications).

6.6.4.2 Detection column temperature: 30 °C.

6.6.4.3 Detector: Differential refractive index detector.

6.6.4.4 Flow rate: 0.5 mL/min.

6.6.4.5 Injection volume: 20 µL.

6.6.5 Analytical procedures

6.6.5.1 Drawing of standard curve

The 8 dextran standard solutions of different average molecular weights are filtered through a 0.22 µm microporous filter membrane, respectively. Turn on

6.8.2 gamma-polyglutamic acid for agriculture

According to the method specified in GB/T 23349.

7.1 Batch

The products are inspected in batches. The products manufactured by one time production forms 1 batch.

7.2 Sampling

It is performed according to GB/T 6679. The sampling size is 30 g. Mix the sampled products uniformly. Then divide it into two parts. One part is used for inspection; the other part is retained for reference.

7.3 Exit-factory inspection

7.3.1 Each batch of products shall be qualified by the quality inspection department of the manufacturer in accordance with this standard and exit- factory after being attached with a certificate of conformity.

7.3.2 The exit-factory inspection items of gamma-polyglutamic acid for cosmetics are sensory indicators, gamma-polyglutamic acid content, pH, loss on drying, molecular weight, light transmittance, total number of colonies. The exit-factory inspection items of gamma-polyglutamic acid for agriculture are sensory indicators, of gamma- polyglutamic acid for content, pH, loss on drying.

7.4 Type inspection

7.4.1 Type inspection items are all items specified in this standard.

7.4.2 Type inspection shall be carried out in one of the following cases:

a) When there are major changes in raw and auxiliary materials;

b) When changing critical processes or equipment;

c) When the production of the new trial product or the normal production product is stopped for 3 months and then resumed;

d) When there is a large difference between the results of the exit-factory inspection and the last type inspection;

e) When the national quality supervision agency needs random inspection according to relevant provisions.

......