HG/T 2222-1991 Determination of free moisture in triple superphosphate Vacuum oven method HG/T2222-1991 Standard download decompression password: www.bzxz.net

Chemical Industry Standard of the People's Republic of China
HG2222—91
Determination of Free Water in TSP
Vacuum Oven Method
Published on November 15, 1991
Ministry of Chemical Industry of the People's Republic of ChinabZxz.net
Implementation on July 1, 1992
Chemical Industry Standard of the People's Republic of China
Determination of Free Water in TSP
Vacuum Oven Method
1 Subject Content and Scope of Application
This standard specifies the determination of free water in TSP by vacuum oven method. This standard is applicable to the determination of free water in TSP. 2 Principle
HG2222—91
Under certain temperature and vacuum degree, TSP sample is dried under reduced pressure at a fixed time, and the free water is expressed by weight loss. 3 Instruments
Usually laboratory instruments and
3.1 Electric constant temperature vacuum drying oven (vacuum oven): can maintain constant temperature at 50±2℃ and vacuum degree of 64.0~70.7kPa: 3.2 Vacuum pump,
3.3 Weighing bottle: diameter 50mm, height 30mm. 4 Operation steps
Weigh about 2g of sample (accurate to 0.001g), transfer it into a weighing bottle that has been dried and weighed under the test conditions in advance, place it in a vacuum oven at 50±2℃ and vacuum degree 64.0~70.7kPa (equivalent to 480~530mmHg) and dry it for 2h±10min, take it out, cool it in a desiccator, and weigh it.
5 Expression of results
5.1 Free moisture X expressed as a percentage by mass is calculated as follows: x_mo-m1×100
Where: mo——mass of the sample before drying, g; mi
mass of the sample after drying, g.
The result should be expressed to two decimal places.
5.2 Allowable difference
5.2.1 The arithmetic mean of the parallel determination results is taken as the determination result. 5.2.2 The absolute difference of the parallel determination results shall not exceed 0.20%. 5.2.3 The absolute difference of the determination results of different laboratories shall not exceed 0.30%. Approved by the Ministry of Chemical Industry of the People's Republic of China on November 15, 1991 and implemented on July 1, 1992
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Additional Notes:
HG 2222-91
This standard was proposed by the Science and Technology Department of the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of the Shanghai Research Institute of Chemical Industry of the Ministry of Chemical Industry. This standard was drafted by the Shanghai Research Institute of Chemical Industry of the Ministry of Chemical Industry and Yunnan Phosphate Fertilizer Factory. The main drafters of this standard are Yin Yongkang, Chen Xuezhi, Xie Ruiming and Hua Xiaoxian. This standard refers to the AOAC (14th edition) "Determination of free water in fertilizers - Vacuum oven method".
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