GB 22489-2017Feed additive-Manganese methionine complex (chelate) (English PDF)

4.2.1 Reagents and solutions

4.2.1.1 Methanol.

4.2.1.2 Trichloromethane.

4.2.1.3 pyridine naphthol (PAN) chloroform solution (0.1mg/mL). Weigh 0.01gPAN dissolved in 100mL trichloromethyl Alkane.

4.2.1.4 Potassium hydroxide methanol solution (0.01g/mL) Weigh 1g of potassium hydroxide dissolved in 100mL of methanol.

4.2.2 Identification method Weigh 1.0g sample, extracted with 25mL of methanol (4.2.1.1), filtered, the filtrate 1.0mL, was added pyridylazonaphthol (PAN) tris

1.0 mL of methyl chloride solution (4.2.1.3) and

0.5 mL of potassium hydroxide methanol solution (4.2.1.4) to give a purple solution.

4.3 moisture According to the method specified in GB/T 6435 Determination.

4.4 smashing size According to the method specified in GB/T 5917.1 Determination.

4.5 Determination of total arsenic Pre-treatment according to the provisions of

5.4.1.2 GB/T 13079-2006, determination according to GB/T 13079-2006 in Chapter 5 get on.

4.6 Determination of lead Pretreatment according to the provisions of

7.1.2.1 GB/T 13080-2004, determined according to GB/T 13080-2004 in 7.2,

7.3 regulations Set to.

4.7 Determination of cadmium According to the method specified in GB/T 13082 Determination.

4.8 Determination of manganese content

4.8.1 Principle In a phosphoric acid medium, the divalent manganese in the sample is quantitatively oxidized to trivalent manganese with ammonium nitrate at.200 ° C. to 220 ° C., N-benzyloxide Aminobenzoic acid as an indicator, ammonium ferrous sulfate standard titration solution titration.

4.8.2 Reagents and materials

4.8.2.1 Phosphoric acid.

4.8.2.2 Ammonium nitrate.

4.8.2.3 Anhydrous sodium carbonate.

4.8.2.4 N-phenyl-anthranilic acid indicator solution .2g/L. Weigh 0.2gN-phenyl-anthranilic acid, dissolved in a small amount of water, add 0.2g anhydrous sodium carbonate, low temperature heating to dissolve water to 100mL, shake.

4.8.2.5 Phosphorus Mixed Acid Add 150mL sulfuric acid and 150mL phosphoric acid to 700mL water, shake well and cool.

4.8.2.6 Potassium dichromate standard solution .c (1/6K2Cr2O7) is about 0.1mo1/L. Weigh at 120 °C bake to a constant mass basis weight Potassium Chromate about 4.9g (accurate to 0.0001g), placed in 1000mL volumetric flask, add the appropriate amount of water dissolved, diluted to the mark, shake.

4.8.2.7 Ferrous ammonium sulfate standard titration solution .c [Fe (NH4) 2 (SO4) 2] is about 0.1mol/L. Ferrous ammonium sulfate standard titration solution The calibration should be performed simultaneously with the sample determination. Weigh 40g ammonium ferrous sulfate, add (14) sulfuric acid solution 300mL, add 700mL of water after dissolving, shake. Weigh 25mL potassium dichromate standard solution, add 10mL phosphoric acid, add water to 100mL. Ferrous ammonium sulfate standard Titration to orange yellow disappeared. Add 2 drops of N-phenyl-anthranilic acid indicator solution, continue titration until the solution was bright green is the end. Ferrous ammonium sulfate standard titration solution concentration (c1) according to equation (1) calculation. c1 = V1m1 49.03V (1) In the formula. m1

--- Weigh the actual quality of potassium dichromate in grams (g); 49.03

--- Molar mass of potassium dichromate (1/6K2Cr2O7) in grams per mole (g/mol); V1

--- Remove the volume of potassium dichromate standard solution, in milliliters (mL); V

--- titration consume ammonium ferrous sulfate standard titration solution volume, in milliliters (mL).

4.8.3 Analysis steps Weigh about 0.5g sample (accurate to 0.0001g), placed in 500mL Erlenmeyer flask, moistened with a small amount of water. Add 20 mL of phosphoric acid (4.8.2.1), shake well and heat until the solution is just sepia (at this time the temperature is.200 °C ~ 220 °C), add 4g ammonium nitrate (4.8.2.2) And shake well until the yellow smoke exhausted, cooled to 70 °C, add 100mL of water, shake, dissolve, cooled to room temperature. Ferrous ammonium sulfate standard Titration solution (4.8.2.7) titration to light red, add 2 drops of N-phenyl-anthranilic acid indicator solution (4.8.2.4), continue to titrate the solution from Red to bright yellow is the end.

4.8.4 Analysis of the results of the statement Manganese content in mass fraction X1, the value is expressed in%, according to equation (2) calculation. X1 = c1V2 × 0.05494 m2 × 100 (2) In the formula. c1

--- ferrous ammonium sulfate standard titration solution actual concentration in units of moles per liter (mol/L); V2

4.9 Determination of methionine content

4.9.1 Principle Excess iodine solution is added accurately in neutral medium, two iodine atoms combine with sulfur atom on methionine, excess iodine solution is treated with thio Sodium sulfate standard solution back drop, so as to find out the content of methionine in the sample.

4.9.2 Reagents and solutions

4.9.2.1 Hydrochloric acid solution (1 1).

4.9.2.2 sodium hydroxide solution (20%).

4.9.2.3 Sulfuric acid (20%).

4.9.2.4 dipotassium hydrogen phosphate solution.200g/L.

4.9.2.5 potassium dihydrogen phosphate solution.200g/L.

4.9.2.6 Potassium iodide.

4.9.2.7 iodine solution .c (1/2I2) is about 0.1mol/L. Weigh 13g iodine and 35g potassium iodide dissolved in water, diluted to 1000mL, shake Uniform, stored in brown bottle.

4.9.2.8 sodium thiosulfate standard solution .c (Na2S2O3) is about 0.1mol/L, according to GB/T 601 preparation and calibration.

4.9.2.9 starch indicator solution .10g/L.

4.9.3 Analysis steps Weigh the sample about 1.5g (accurate to 0.0001g) in a 100mL beaker, respectively, add 50mL water, 3mL hydrochloric acid solution (4.9.2.1), plus Heat dissolved, with sodium hydroxide solution (4.9.2.2) to adjust the pH to about 13, boiled 3min, cooled and moved into 250mL volumetric flask, diluted with water To the mark, mix well. Filter, accurately remove 50mL filtrate in 250mL iodine bottle, add 50mL of water, with sulfuric acid solution (4.9.2.3) tune A pH of 7 was added to a solution of 10 mL of potassium phosphate dibasic (4.9.2.4), 10 mL of potassium dihydrogen phosphate (4.9.2.5), 2 g of potassium iodide (4.9.2.6), Evenly add 50mL iodine solution (4.9.2.7), cover the bottle, seal, shake, placed in the dark for 30min, with sodium thiosulfate standard solution Liquid (4.9.2.8) Titration to the near end, adding 3mL starch indicator solution (4.9.2.9), continue titration until the solution blue disappears as the end point. Simultaneously Make a blank test.

4.9.4 Calculation Results Methionine content in terms of mass fraction X2, the value is expressed in%, according to equation (3) calculation. X2 = (V3-V4) × c2 × 0.0746 × 5 m3 × 100 (3) In the formula. V3

--- titration blank solution consumed sodium thiosulfate standard solution volume, in milliliters (mL); V4

--- titration sample solution consumed sodium thiosulfate standard solution volume, in milliliters (mL); c2

--- sodium thiosulfate standard solution of the actual concentration in units of moles per liter (mol/L); 0.0746

15.0 Methionine /% >=79.5 >=

40.0 Network (chelation) rate /% >= 93.0 >=

83.0 Moisture /% <=