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In this standard, clauses 1, 4 and 6 are compulsory and the rest are voluntary.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 22549-2008 Feed grade - Dicalcium phosphate.
In addition to editorial changes, the following main technical changes have been made with respect to GB/T 22549-2008:
——The index parameters of arsenic is modified from 0.003% to 20 mg/kg (see 4.2; 5.2 of Edition 2008);
——The dithizone spectrophotometric method used for determination of lead content is deleted (6.11.2 of Edition 2008);
——The index parameters and test methods for chromium content are added (see 4.2 and 5.13);
——The index parameters and test methods for free moisture content are added (see 4.2 and 5.15).
This standard was proposed by and is under the jurisdiction of SAC/TC 76 National Technical Committee on Feed Industry of Standardization Administration of China.
The previous edition of this standard is as follows:
——GB/T 22549-2008.
Feed additive - Diealcium phosphate
1 Scope
This standard specifies the requirements, test methods, inspection rules as well as labeling, packaging, transport and storage of the feed additive - diealcium phosphate.
This standard is applicable to feed additive - diealcium phosphate produced with wet-process phosphoric acid according to certain calcium-phosphorus ratio.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 601 Chemical reagent - Preparations of reference titration solutions
GB/T 602 Chemical reagent - Preparations of standard solutions for impurity
GB/T 603 Chemical reagent - Preparations of reagent solutions for use in test methods
GB/T 6003.1-2012 Test sieves - Technical requirements and testing - Part 1: Test sieves of metal wire cloth
GB/T 6436-2002 Determination of calcium in feed
GB/T 6682-2008 Water for analytical laboratory use - Specification and test methods
GB 10648 Feed label
GB/T 13079-2006 Determination of total arsenic in feeds
GB/T 13080-2004 Determination of lead in feeds - Method using atomic absorption spectrometry
GB/T 13082-1991 Method for determination of cadmium in feeds
GB/T 13083-2002 Determination of fluorine in feed - Ion selective electrode method
GB/T 13088-2006 Determination of chromium in feeds
GB/T 14699.1 Feeding stuffs - Sampling
3 Classification
It shall be classified by production process into Types I, II and III.
4 Requirements
4.1 Appearance: white or slightly yellowish powder or granule.
4.2 The feed additive - diealcium phosphate, if inspected by the test methods specified in this standard, shall meet the technical requirements in Table 1.
Table 1 Technical requirements
Item Index
Type I Type II Type III
Total phosphorus (P), ω/% ≥ 16.5 19.0 21.0
Citric acid soluble phosphorus (P), ω/% ≥ 14.0 16.0 18.0
Water-soluble phosphorus (P), ω/% ≥ - 8.0 10.0
Calcium (Ca), ω/ % ≥ 20.0 15.0 14.0
Fluorine (F)/(mg/kg) ≤ 1,800
Arsenic (As)/(mg/kg) ≤ 20
Lead (Pb)/ (mg/kg) ≤ 30
Cadmium (Cd)/(mg/kg) ≤ 10
Chromium (Cr)/(mg/kg) ≤ 30
Free moisture, ω/% ≤ 4.0
Fineness, ω/% Powder, passing through a 0.5-mm test sieve ≥ 95
Fineness, passing through a 2-mm test sieve ≥ 90
Note: Other special requirements of the user for fineness, shall be subjected to negotiation between the Supplier and the Demander.
5 Test methods
5.1 Warning
Some of the reagents used in this test are corrosive, therefore, must be handled with care! If necessary, this test shall be performed in a fume cupboard. If the reagent is splashed on the skin, rinse it immediately with water. In severe cases, seek medical attention immediately.
5.2 General requirements
If no other requirements are noted, the reagents and water used in this standard refer to analytical reagents and distilled water, or Grade 3 water specified in GB/T 6682-2008. If no other requirements are noted, the standard volumetric solutions, standard solutions for impurity, preparations and products used in the test shall be prepared in accordance with the requirements of GB/T 601, GB/T 602 and GB/T 603.
5.3 Sensory inspection
Visual method is adopted for judging the appearance under sufficient natural light.
5.4 Identification
5.4.1 Reagents and materials
5.4.1.1 Glacial acetic acid.
5.4.1.2 Hydrochloric acid solution: 1+1.
5.4.1.3 Ammonia solution: 1+1.
5.4.1.4 Ammonium oxalate solution: 100 g/L.
5.4.1.5 Silver nitrate solution: 17 g/L.
5.4.2 Identification of calcium ion
Take about 0.1 g of specimen, add 5 mL of glacial acetic acid to dissolve it, and boil the solution. After cooling, filter it and add 5 mL of ammonium oxalate solution to the filtrate to produce white precipitation which is soluble in hydrochloric acid solution.
5.4.3 Identification of phosphate radical
Take about 0.1 g of specimen, dissolve it in 10 mL of water, add 1 mL of silver nitrate solution to produce yellow precipitation which is soluble in excessive ammonia solution but insoluble in glacial acetic acid.
5.5 Determination of total phosphorus content
5.5.1 Method summary
In acidic medium, all the phosphate radical in the test solution react with the quimociac precipitant added and produce precipitation. Then filter, dry and weigh the precipitate, and calculate the total phosphorus content.
5.5.2 Reagents and materials
5.5.2.1 Hydrochloric acid solution: 1+1.
5.5.2.2 Nitric acid solution: 1+1.
5.5.2.3 Quimociac solution:
a) Weigh 70 g of sodium molybdate (Na2MoO4·2H2O) and dissolve it in 100 mL of water;
b) Weigh 60 g of citric acid (C6H8O7·2H2O) and dissolve it in 150mL of water;
c) Pour Solution a) into Solution b) while stirring;
d) Add 25 mL of concentrated nitric acid and 5 mL of quinoline into 100 mL of water;
e) Pour Solution d) into Solution c), then allow it to stand for 12 h, after that, filter it with sintered-glass filter crucible, and then add 280 mL of acetone into it, dilute it with water to 1,000 mL, shake well and pour the solution into polyethylene bottle for preservation.
5.5.3 Instruments
5.5.3.1 Sintered-glass filter crucible: the hole diameter of filter plate is 5μm ~15μm.
5.5.3.2 Electric thermostatic drying oven: with the temperature capable of being controlled at 180℃±5℃.
5.5.4 Analytical procedure
5.5.4.1 Preparation of Test Solution A
Weigh about 1.0 g of specimen, accurate to 0.0002 g, and put it into a 100-mL beaker, then add 10 mL of hydrochloric acid and a small amount of water, cover the watch glass, and boil it for 10 min. Cool it off, transfer it into a 250-mL volumetric flask, and dilute it to the scale with water and shake it well. This solution is Test Solution A which is used for the determination of total phosphorus and calcium content.
Foreword i
1 Scope
2 Normative references
3 Classification
4 Requirements
5 Test methods
6 Inspection rules
7 Labeling, packaging, transport and storage
8 Guarantee period
