GB/T 2441.5-2001 Urea determination method Alkalinity determination volumetric method GB/T2441.5-2001 standard download decompression password: www.bzxz.net

GB/T 2441.5—2001
This standard is a revision of GB/T2446-1991 "Volume method for determination of alkalinity of industrial urea". This standard adopts ISO1593:1977 "Volume method for determination of alkalinity of industrial urea" in a non-equivalent manner. The main technical differences between this standard and ISO1593:1977 and GB/T2446—1991 are as follows: 1. The basic standard HG/T2843--1997 for the chemical industry is quoted, and the GB/T601 series standards are no longer quoted. 2. The sample weight of the test material is specified in the analysis step. This standard is Part 5 of GB/T2441 "Determination of urea method". GB/T2441 also includes the following parts:
GB/T 2441.1—-2001
Part 1
Part 2 (
GB/T 2441.2--2001
GB/T 2441.3—2001
Part 3
Part 4 GB/T2441.4—2001
Part 6
Part 7
GB/T 2441.6—2001
GB/T 2441.7—2001
GB/T 2441. 8---2001
Part 8
Part 9
GB/T 2441.9-2001
Determination of total nitrogen content
Urea determination method
Urea determination method
Determination of dihydrogen phosphate content-spectrophotometric method
Determination of water content-Karl Fischer method
Urea determination methodwwW.bzxz.Net
Urea determination method
Urea determination method
Urea determination method
Urea determination method
Urea determination method||t t||This standard replaces GB/T2446-1991 from the date of implementation. This standard is proposed by the State Bureau of Petroleum and Chemical Industry. Determination of iron content O-phenanthroline spectrophotometric method Determination of water-insoluble content Gravimetric method
Determination of particle size Sieving method
Determination of sulfate content Visual turbidimetry
Determination of methylenediamine content Spectrophotometric method This standard is under the jurisdiction of the National Technical Committee for Standardization of Fertilizers and Soil Conditioners and is responsible for its interpretation. Drafting units of this standard: National Fertilizer Quality Supervision and Inspection Center (Shanghai), Fertilizer Plant of Urumqi Petrochemical Company of PetroChina , Sinopec Jiujiang Branch, Hainan Fudao Chemical Co., Ltd. The main drafters of this standard are Zhang Qiuzhen and Yang Jiqun. This standard was first issued in 1981.
GB/T2441.5-2001
ISO Foreword
ISO (International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The development of international standards is usually carried out through ISO technical committees. Each member body interested in the project of an established technical committee has the opportunity to join the technical committee. International organizations, governmental or non-governmental, in liaison with ISO may also take part in the work. Draft international standards adopted by technical committees are circulated to member bodies for approval before being approved as international standards by the ISO Council.
Prior to 1972, the results of the work of technical committees were published as ISO recommended standards, and these documents are in the process of becoming international standards. As part of this process, ISO/TC47 Technical Committee on Chemistry reviewed ISO Recommendation R1593-1970 and found it to be technically suitable for conversion to an international standard. Therefore, ISO Recommendation R1593-1970, which is technically identical, is replaced by International Standard ISO 1593.
The member states that agree to the IS0 recommended standard R1593 are as follows: Australia
Australia
Belgium
Canada
Czechoslovakia
Hungary
Israel
Italy
New Zealand
Portugal
Romania
No member state disagrees with this recommended standard. South Africa
Spain
Turkey
Yugoslavia
No member state disagrees with this recommended standard becoming an international standard. 88
1 Scope
National Standard of the People's Republic of China
Determination of urea
Determination of alkalinity-Titrimetric method This standard specifies the determination of alkalinity in urea by volumetric method. This standard is applicable to the determination of alkalinity of industrial urea synthesized from ammonia and carbon dioxide. Cited Standards
GB/T2441.5—2001
neq ISO 1593:1977
Replaces GB/T2446-1991
The provisions contained in the following standards constitute the provisions of this standard through reference in this standard. When this standard was published, the versions shown were valid. All standards are subject to revision. Parties using this standard should explore the possibility of using the latest version of the following standards: HG/T2843--1997 Standard titration solutions, standard solutions, reagent solutions and indicator solutions commonly used in chemical analysis of fertilizer products 3 Principle
In the presence of indicator solution, the alkalinity of the sample is titrated with hydrochloric acid standard titration solution. 4 Reagents and solutions
Unless otherwise specified, the reagents, solutions and water used in this test method shall comply with the requirements of HG/T2843. 4.1 Methyl red-methylene blue mixed indicator solution; 4.2 Hydrochloric acid standard titration solution, c(HCI)=0.1 mol/L. 5 Instruments
General laboratory instruments.
6 Analysis steps
Weigh about 50g of laboratory sample (accurate to 0.05g), place the sample in a 500mL conical flask, add about 350mL of water to dissolve the sample, add 3 to 5 drops of mixed indicator solution, and then titrate with hydrochloric acid standard titration solution until the solution turns gray-green. 7 Expression of analysis results
Alkalinity (X) in the sample, expressed as the mass fraction (%) of nitrogen (NH3) is calculated as follows: X = cV× 0.017 × 100_cV × 1.7m
Wherein: -—concentration of hydrochloric acid standard titration solution, mol/l; volume of hydrochloric acid standard titration solution consumed in the determination, mL; V
-mass of the sample, g;
Approved by the General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China on July 26, 2001m
Implementation on January 1, 2002
GB/T2441.5—2001
0.017—with 1.00mL hydrochloric acid standard titration solution [c(HCI)=0.100 0mol /L] The mass of ammonia in grams equivalent to the parallel determination results is taken as the arithmetic mean as the determination result, and the result is expressed to three decimal places. 8 Tolerance
The absolute difference of the parallel determination results shall not exceed 0.001%; ​​the absolute difference of the determination results of different laboratories shall not exceed 0.002%.
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