GB 22548-2017Feed additive-Monocalcium phosphate (English PDF)

4.4.1.1 Glacial acetic acid

4.4.1.2 Hydrochloric acid solution: 1+1.

4.4.1.3 Ammonia solution: 1+1.

4.4.1.4 Ammonium oxalate solution: 100 g/L.

4.4.1.5 Silver nitrate solution: 17 g/L.

4.4.2 Identification of calcium ions Take a small amount, about

0.1 g, of sample; add 5 mL of glacial acetic acid to dissolve; boil. Filter after cooling; add 5 mL of ammonium oxalate solution to the filtrate to give a white precipitate. This precipitate is dissolved in a hydrochloric acid solution.

4.4.3 Identification of phosphate radical Take a small amount, about

0.1 g, of the sample; dissolve it in 10 mL of water; add 1 mL of silver nitrate solution to form a yellow precipitate. This precipitate is soluble in excess ammonia solution and insoluble in glacial acetic acid.

4.5 Determination of total phosphorus content

4.5.1 Method summary In the acidic medium, the phosphate radical in the test solution all forms a precipitate with the added quinoxaline ketone precipitant. Calculate the content by filtration, drying, and weighing.

4.5.2 Reagents and materials

4.5.2.1 Hydrochloric acid solution: 1+1.

4.5.2.2 Nitric acid solution: 1+1. is previously constant at 180°C ± 5°C to suction-filter the supernatant; use decantation to wash the precipitate for 5 ~ 6 times. About 20 mL of water shall be used each time; transfer the precipitate to the glass mortar; continue to use water to wash for 3 ~ 4 times. Place the glass mortar in an electrically heated drying oven; bake at 180°C ± 5°C for 45 min; take out and place in a desiccator to cool to room temperature; weigh.

4.5.5 Result calculation The total phosphorus content is calculated, in mass fraction of phosphorus (P) w1, according to Formula (1): Where: m1 -- the mass of quinoline phosphomolybdate precipitate that is formed by the test solution, in grams (g); m0 -- the mass of quinoline phosphomolybdate precipitate that is formed by the blank test solution, in grams (g); m -- sample mass, in grams (g). 0.014 0 -- the conversion coefficient from phosphorus molybdate to phosphorus. Take the arithmetic mean of the parallel determination results as the determination result; the absolute difference between the two parallel determination results shall not be larger than 0.2%.

4.6 Determination of water-soluble phosphorus content Weigh approximately

0.5 g of the sample, accurate to 0.000 2 g, in a porcelain (or agate) mortar. Add water to grind; add 25 mL of water each time; continuously grind for 4 times; transfer all the aqueous solution to a 250 mL volumetric flask; shake for 30 min (2 times/s); use water to dilute to the mark; shake well. Dry filtration; discard the initial 20 mL of filtrate; pipette 20 mL of the filtrate; place it in a 250 mL beaker. The following operations are determined and calculated according to that which starts from "Add 10 mL of nitric acid solution..." of 4.5.4.3; perform a blank test at the same time.

4.7 Determination of calcium content

4.7.1 Method summary Same as Chapter 10 of GB/T 6436-2002.

4.8.2 Reagents Same as Chapter 4 of GB/T 13083-2002.

4.8.3 Instruments Same as Chapter 5 of GB/T 13083-2002.

4.8.4.1 Preparation of test solution A Weigh about

0.5 g ~

1.00 g of sample, accurate to 0.0002 g, in a 100 mL volumetric flask; add 16 mL of hydrochloric acid solution (1+4); use water to dilute to the mark; shake well.

4.8.4.2 Determination Pipette 25 mL of the test solution; place it in a 50 mL volumetric flask; use total ion buffer solution to dilute to the mark; shake well. Determine and calculate according to Chapter 7 of GB/T 13083-2002.

4.9.1 Method summary Same as Chapter

5.1 of GB/T 13079-2006.

4.9.2 Reagents Same as Chapter

5.2 of GB/T 13079-2006.

4.9.3 Instruments Same as Chapter

5.3 of GB/T 13079-2006.

4.9.4.1 Preparation of test solution B Weigh

5.0 g of sample, accurate to 0.000 2 g; add 20 mL of hydrochloric acid solution (1+1); heat to dissolve; cool; place in a 250 mL volumetric flask; add water to dilute to the mark; shake well; dry filter. This filtrate is test solution B, which is for the determination of arsenic, lead, cadmium and chromium contents.

4.9.4.2 Determination Take the arithmetic mean of the parallel determination results as the determination result; the absolute difference between the two parallel determination results shall not be larger than 0.5%.

4.14.1 Instruments and apparatuses Test sieve (in accordance with

GB/T 6003.1-2012): R40/3 series phi200 mm × 50 mm ×

0.5 mm.

4.14.2 Analysis steps Weigh

20.0 g of the sample, accurate to

0.01 g, on a test sieve for sieving; weigh the sieved material.

4.14.3 Result calculation The fineness is calculated, in mass fraction w4, according to Formula (4): Where: m1 -- the mass of the sieved material, in grams (g); m -- sample mass, in grams (g). Take the arithmetic mean of the parallel determinations as the determination result. The absolute difference between the results of two parallel measurements shall not be greater than 0.3%.

4.15 pH determination

4.15.1 Instruments and apparatuses Acidity meter: the division value is 0.02; equipped with a composite electrode or glass electrode and a calomel electrode.

4.15.2 Analysis steps Weigh

0.24 g ±

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