This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of chemical reagent phenol red. This standard applies to the inspection of chemical reagent phenol red. GB/T 15351-1994 Chemical reagent phenol red GB/T15351-1994 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Phenol red
Chemical reagent
Phenol red
GB/T15351-94
This reagent is a red crystalline powder, easily soluble in ethanol and alkaline solution, insoluble in chloroform and ether. Molecular formula: CH, O, S
Structural formula:
Relative molecular mass: 354.38 (according to the 1991 international relative atomic mass) Subject content and scope of application
This standard specifies the technical requirements, test methods, inspection rules, packaging and marking of the chemical reagent phenol red. This standard applies to the inspection of the chemical reagent phenol red. 2 Reference standards
GB/T 601
GB/T 603
GB/T604
GB/T 619
GB/T 6682
GB/T 9721
GB/T 9741
HG 3—119
3 Technical requirements
Chemical reagents
Chemical reagents
Chemical reagents
Chemical reagents
Preparation of standard solutions for titration analysis (volumetric analysis) Preparation of preparations and products used in test methods General method for determination of pH color change of acid and base indicators Sampling and acceptance rules
Specifications and test methods for water used in analytical laboratories Chemical reagents
Chemical reagents
Chemical reagents
3.1 pH color change range:
1.2 (orange) ~ 3.0 (yellow);
6.5 (brown yellow) ~ 8.0 (purple red).
3.2 Maximum absorption wavelength (nm):
A,(pH1. 2)**
A2(pH3. 0)....
A(pH6. 5).....
General rules for molecular absorption spectrophotometry (ultraviolet and visible light part) General method for determination of ignition residue
Packaging and marking
503~506;
430~435;
.·430~435
Approved by the State Administration of Technical Supervision on December 22, 1994 and implemented on October 1, 1995
A(pH8. 0).
3.3 Mass absorption coefficient (L/cm·g):
α,(),pH. 2,dry sample).
α,(>z pH3. 0, dry sample)...
αs(^3pH6.5, thousand sample)
α(^pH8.0, dry sample)...
3.4Maximum impurity content:
Alkali dissolution test
Loss on drying
GB/T 15351—94
557~560.
110～123,
60~68,
.··62~72;
·120~～135.
Ignition residue (calculated as sulfate)
Test method
The standard titration solution, preparation and product and pH buffer solution in this test method shall be prepared in accordance with the provisions of GB/T 601, GB/T603 and GB/T604 unless otherwise specified. The experimental water shall meet the third-grade water specifications in GB/T6682. 4.1 Determination of pH color range
Determine in accordance with the provisions of GB/T604.
4.2 Determination of maximum absorption wavelength
Determine in accordance with the provisions of GB/T9721, where:
4.2.1 Determination conditions
Thickness of absorption cell: 1cm;
Reference solution: water;
Scanning range: 400～700nm.
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 14.20mL of sodium hydroxide standard solution (c(NaOH)-0.02mol/LJ), heat in a water bath to dissolve, cool, place in a 500mL volumetric flask, and dilute to the scale with carbon dioxide-free water, shake well.
Measure 2.00mL, 3.00mL, 3.00mL, and 2.00mL of the above sample solution, each placed in a 100mL volumetric flask, and dilute to the scale with pH1.2, pH3.0, pH6.5, and pH8.0 buffer solutions, respectively, and shake well. According to the provisions of Article 7.2.1 of GB/T9721, measure the maximum absorption wave length 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,
—absorbance measured in Article 4.2.2;
-thickness of the absorption cell, cm;
concentration of the sample solution, g/L.
4.4 Impurity determination
The sample must be weighed accurately to 0.01g.
4.4.1 Alkali dissolution test
GB/T 15351—94
Weigh 0.1g sample, dissolve in 0.3mL sodium hydroxide standard solution Lc(NaOH)=1mol/L, dilute to 250mL, it should be completely dissolved and clear without mechanical impurities.
4.4.2 Loss on drying
Weigh 1g sample, accurate to 0.0001g. Place in a weighing bottle that has been dried to constant weight at 105±2℃, and dry in an electric oven at 105±2℃ to constant weight.
Loss on drying is calculated according to formula (2):
X=m=m × 100www.bzxz.net
Wherein: X—loss on drying, %;
mt-mass of sample before constant weight, g,
mass of sample after constant weight, g.
4.4.3 Residue on ignition
Weigh 0.5g sample and measure according to the provisions of Article 4.1 of GB/T9741. The result shall be calculated according to the provisions of Chapter 5 of GB/T9741. 5 Inspection rules
Sampling and acceptance shall be carried out according to the provisions of GB/T619. 6 Packaging and marking
According to HG 3--119, among which:
Inner packaging form: Gz-3,
Outer packaging form: W-1
Packing unit: Class 2.
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 Hao Yulin, Guan Ruibao, Qiang Jinglin, and Liu Dongyuan. From the date of implementation of this standard, the former Ministry of Chemical Industry standard HG3-957-76 Chemical Reagent: Phenol Red will be invalid. 1145
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