GB/T 21694-2008Feed additive -- Zinc methionine complex (chelate) (English PDF)

3.1 Appearance and traits

Methionine zinc (chelate) complexes with a molar ratio of 2. 1 are white or almost white powder, very slightly soluble in water, light in weight and slightly methionine-specific taste. No caking, moldy phenomenon.

The methionine zinc complex (chelate) with a molar ratio of 1. 1 is white or almost white powder, soluble in water, slightly methionine-specific odor. no Caking, moldy phenomenon.

3.2 Specifications

Feed additive methionine zinc (chelate) products should be consistent with the provisions of Table 1.

Table 1 technical indicators

project

index

The molar ratio of 2. 1 product is 1. 1 Zinc (Zn) /% >=17.2 >=19.0 Methionine /% >=78.0 >=42.0 Chelation rate /% >=95 >=35 Moisture /% <=2 <=5 Total arsenic (As)/(mg/kg) <=5 Lead (Pb)/(mg/kg) <=5 Cadmium (Cd)/(mg/kg) <=6 Particle size (0.20 mm sieve) /% <=2

4.1 Sensory test

Take the right amount of sample placed on a white paper, observe the color under natural light, smell its taste.

4.2 Identification

4.2.1 Reagents and solutions

4.2.1.1 Methanol.

4.2.1.2 Trichloromethane.

4.2.1.3 o-Phenanthroline trichloromethane solution (0.1g/L). Weigh 0.01g o-phenanthroline, dissolved in 100mL of chloroform (4.2.1.2).

4.2.1.4 eosin methanol solution (0.1%). Weigh 0.1g eosin, dissolved in 100mL of methanol (4.2.1.1).

4.2.1.5 Potassium hydroxide methanol solution (0.5mol/L) Weigh 2.805g potassium hydroxide, dissolved in 100mL of methanol (4.2.1.1).

4.2.2 Identification

Weigh 1.0g sample, extracted with 25mL of methanol (4.2.1.1), filtered, the filtrate was taken 0.1mL, respectively, by adding phenanthroline trichloride Methane solution (4.2.1.3) 2mL, eosin methanol solution (4.2.1.4) 3 drops of methanol solution of potassium hydroxide (4.2.1.5) 1mL, shall not appear turbid.

4.3 Determination of zinc content

According to HG2934-2000 5.2 Determination.

Determination of methionine content 4.4

4.4.1 Principle

Excess iodine solution is added accurately in neutral medium, two iodine atoms are added to the sulfur atom of methionine, the excess iodine solution is treated with sulfur Substitution of sodium sulfate standard titration solution back to the sample from the consumption of sodium thiosulfate standard titration solution volume calculated methionine content of the sample.

4.4.2 Reagents and materials

4.4.2.1 Potassium iodide.

4.4.2.2 hydrochloric acid solution .6mol/L.

4.4.2.3 Sodium hydroxide solution .20%.

4.4.2.4 sulfuric acid solution. Sulfuric acid water = 15.

4.4.2.5 potassium dihydrogen phosphate solution .200 g/L.

4.4.2.6 dipotassium hydrogen phosphate solution .200 g/L.

4.4.2.7 iodine solution .c (1/2I2) = 0.1mol/L.

4.4.2.8 sodium thiosulfate standard titration solution .c (Na2S2O3) = 0.1mol/L.

4.4.2.9 Starch indicator solution .10g/L.

4.4.3 Analysis steps

Weigh 1.5g sample, weighed to 0.0001g, placed in 100mL beaker, add 50mL water, 3mL hydrochloric acid solution (4.4.2.2), plus Heat dissolved, with sodium hydroxide solution (4.4.2.3) to adjust the pH greater than or equal to 13, boiled 3min, cooled and moved into 250mL volumetric flask, Dilute to the mark, take the supernatant filtration, accurately remove 50mL filtrate in iodine bottle, add 50mL of water, with sulfuric acid solution (4.4.2.4) tune A pH of 7 was added and 10 mL potassium dihydrogen phosphate solution (4.4.2.5), 10 mL dipotassium hydrogen phosphate solution (4.4.2.6), 2 g potassium iodide (4.4.2.1), Shake, accurately add 50mL iodine solution (4.4.2.7), evenly, in the dark place 30min, with sodium thiosulfate standard titration solution (4.4.2.8) drops Set until the solution color changes from dark blue to light blue, add 3 mL of starch indicator solution (4.4.2.9) and continue titration until the solution blue disappears.

At the same time, take another 100mL beaker and 250mL Erlenmeyer flask, a blank test, in addition to without the sample, the other operations and add the reagent species Class and quantity are the same with the test.

4.4.4 Calculation and representation of results

Methionine content in the sample X1 mass fraction, the value is expressed in%, according to equation (1) calculation.

(V0-V1) × c1 × M1 × 10-3 × 5 m1 × 100 (1) in the formula.

V0 --- titration blank solution consumed sodium thiosulfate standard titration solution (4.4.2.8) volume, in milliliters (mL);

Volume of titration solution of sodium thiosulfate standard titration solution (4.4.2.8) consumed by titration sample solution in milliliters (mL);

c1 --- sodium thiosulfate standard titration solution (4.4.2.8) the actual concentration in units of moles per liter (mol/L);

M1 --- and consume 1moL sodium thiosulfate standard titration solution (4.4.2.8) equivalent methionine content, in grams per mole (g/mol) (M1 = 74.6);

m1 --- sample quality, in grams (g).

The arithmetic mean of the two parallel determination results is the determination result, and the result is retained to one decimal place.

The absolute difference between the two measurements is not more than 1%.

4.5 Chelation rate determination

According to the method specified in GB/T 13080.2 Determination.

4.6 Determination of moisture content

According to GB/T 6435 determination.

4.7 Determination of total arsenic content

Sample pretreatment according to GB/T 13079-2006 in 5.4.1.2, measured by GB/T 13079-2006 in Chapter 5.

4.8 Determination of lead content

Pre-treatment of samples according to GB/T 13080-2004 in 7.1.2.1, measured according to GB/T 13080-2004. Sample determination required Deduct the background.

4.9 Determination of cadmium content

Pre-treatment of samples according to GB/T 13082-1991 in 6.1, measured according to GB/T 13082-1991.

4.10 Determination of particle size

According to GB/T 5917.1 determination.

5.1 Group approved

With the same material, the same production process, continuous production or the same batch of products produced for a group.

5.2 Sampling

According to the provisions of GB/T 14699.1 sampling.

5.3 Factory inspection

The items listed in Table 1, zinc, methionine, moisture, total arsenic and lead content for the factory inspection items.

5.4 Type test

Type inspection items for all the requirements of Chapter 3. Product normal production, at least once every six months type test, but the following conditions when one of the conditions, also conducted type testing.

a) when the product is shaped

b) there is a big change in the production process or the source of raw materials, which may affect the product quality;

c) stop production for more than three months, to resume production;

d) the factory test results and the last type test results are quite different.

5.5 Decision rules

Inspection results have an indicator does not meet the requirements of this standard, should be re-sampled twice from the amount of packaging reinspection, retest results even There is an indicator does not meet the requirements of this standard, the entire batch of products is unqualified.

6.1 Label

According to GB 10648 implementation.

6.2 Packaging

Packaging materials should be non-toxic, harmless, moisture-proof.

6.3 Transportation

Prevent packaging damage during transport, the sun, rain, prohibit co-operation with toxic and hazardous substances.

6.4 Storage

Storage to prevent the sun, rain, toxic and harmful substances prohibited mixing.