Basic Information
Standard ID:
GB/T 15350-1994
Standard Name: Chemical reagent m-cresol purple
Chinese Name:
化学试剂 间甲酚紫
Standard category:National Standard (GB)
state:Abolished
Date of Release1994-01-02
Date of Implementation:1995-10-01
Date of Expiration:2005-10-14
other information
Review date:2004-10-14
Drafting unit:Beijing Chemical Plant
Focal point unit:National Technical Committee on Chemical Standardization
Publishing department:State Bureau of Technical Supervision
competent authority:China Petroleum and Chemical Industry Association
Some standard content:
National Standard of the People's Republic of China
Chemical reagent
m-Cresol purple
GB/T 15350—94
This reagent is green-brown or brown powder. Slightly soluble in water and ethanol. Its alkaline solution is purple, weak acid solution is yellow: strong acid solution is pink.
Molecular formula: CzHi.OS
Structural formula:
Relative molecular mass, 382.44 (according to the 1991 international relative atomic mass) 1 Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of chemical reagent m-cresol purple. This standard applies to the inspection of chemical reagent m-cresol purple. 2 Reference standards
GB/T 601
GB/T603
GB/T604
GB/T619
GB/T 6682
GB/T.9721
HG3—119
3 Technical requirements
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Preparation of standard solutions for titration analysis (volume analysis) Preparation of preparations and products used in test methods Acid-base indicators pH General method for color change range determination Sampling and acceptance rules
Specifications and test methods for water in analytical laboratories Chemical reagents
Chemical reagents
3.1pH color change range:
1.2 (pink) ~ 2.8 (yellow),
7.4 (brown yellow) ~ 9.0 (purple).
3.2 Maximum absorption wavelength (nm):
A,(pH1.2)..
2(pH2. 8)..
A2(pH7. 4)...*
General rules for molecular absorption spectrophotometry (ultraviolet and visible light parts) Packaging and marking
526529
431~437
431~437;
Approved by the State Administration of Technical Supervision on December 22, 1994 1140
Implemented on October 1, 1995
A(pH9. 0).
3.3 Mass absorption coefficient (L/cm·g):α,(A,pH1. 2, dry sample)....
α2(^2,pH2.8, dry sample)...
α:(^3,pH7.4, dry sample)..
α(,pH9.0, dry sample).
3.4Maximum impurity content:
Ethanol solubility test
Loss on drying, %
4Test method
GB/T 15350—94
576~580
80-94-
...40~46
…39~45
75~~86.
The standard titration solutions, preparations and products and pH buffer solutions in this test method shall be prepared according to the provisions of GB/T601, GB/T603 and GB/T604 unless otherwise specified. The experimental water shall meet the specifications of Grade 3 water in GB/T6682. 4.1 Determination of pH color range
Determine according to the provisions of GB/T604.
4.2 Determination of maximum absorption wavelength
Determine according to the provisions of GB/T9721, where: 4.2.1 Determination conditions
Thickness of absorption cell: 1 cm;
Reference solution: water,
Scanning range: 400~700 nm.
4.2.2 Determination method
Weigh 0.100g of the sample that has been dried to constant weight at 105±2℃ in advance, accurate to 0.0001g. Add 13.6mL of sodium hydroxide standard bath solution (c(NaOH)=0.02mol/L), heat in a water bath to dissolve, cool, and place in a 500mL volumetric flask, dilute to scale with carbon dioxide-free water, and shake well.
Measure 2.00mL, 4.00mL, 4.00mL, and 2.00mL of the above sample solutions, place them in 100mL volumetric flasks, dilute to scale with pH1.2, pH2.8, pH7.4, and pH9.0 buffer bath solutions, and shake well. According to the provisions of Article 7.2.1 of GB/T9721, measure the maximum absorption wavelength and the corresponding absorbance A (A is used to calculate the mass absorption coefficient). 4.3 Mass absorption coefficient
The mass absorption coefficient is calculated according to formula (1):
Wherein: α—mass absorption coefficient, L/cm·g, A—absorbance measured in 4.2.2, b——thickness of absorption cell, cm,
C sample solution concentration, g/L.
4.4 Impurity determination
The sample must be weighed accurately to 0.01g.
4.4.1 Ethanol dissolution test
Weigh 0.1g sample, add 100mL ethanol, heat in a water bath to dissolve, it should be completely dissolved and clear without mechanical impurities. 4.4.2 Loss on drying
GB/T15350-94
Weigh 1g of sample, accurate to 0.0001g, and place it in a weighing bottle that has been dried to constant weight at 105±2℃, and dry it in an electric oven at 105±2℃ to constant weight.
Loss on drying is calculated according to formula (2):
X=m=m×100
Where: X—loss on drying, %
-mass of sample before constant weight,,
mass of sample after constant weight, nom.
5 Inspection rules
Sampling and acceptance shall be carried out in accordance with the provisions of GB619. 6 Packaging and marking
According to the provisions of HG3-119, among which:
Inner packaging form: Gz-3;
Outer packaging form: W-1,
Packing unit: Class 2. www.bzxz.net
Additional instructions:
This standard is proposed by the Ministry of Chemical Industry of the People's Republic of China. This standard is under the jurisdiction of Beijing Chemical Reagent General Factory. This standard is drafted by Beijing Chemical Factory. The main drafters of this standard are Qiang Jinglin, Guan Bao, Hao Yulin, and Liu Dongyuan. From the date of implementation of this standard, the original Ministry of Chemical Industry standard HG 3--1221-79 "Chemical Reagent Metacresol Purple" will be invalid. 1142
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