GB/T 6324.5-2008 English PDF (GBT6324.5-2008)

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GB/T 6324.5-2008: Test method of organic chemical products -- Part 5: Determination of trace quantities of carbonyl compounds in organic chemicals
GB/T 6324.5-2008
GB
NATIONAL STANDARD OF
THE PEOPLE’S REPUBLIC OF CHINA
ICS 71.080.01
G 15
Replacing GB/T 6324.5-1986, GB/T 6324.6-1986
Test method of organic chemical products –
Part 5. Determination of trace quantities of carbonyl
compounds in organic chemicals
ISSUED ON. JUNE 4, 2008
IMPLEMENTED ON. DECEMBER 1, 2008
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration Committee.
Table of Contents
Foreword ... 3 
1 Scope ... 5 
2 Normative references ... 5 
3 Safety and preventative measures ... 6 
4 Test method ... 6 
5 Expression of results ... 10 
Annex A (Informative) Comparison on clause number between this Part and
ASTM E 411-2005 ... 12 
Foreword
GB/T 6324 Test method of organic chemical products consists of six parts.
- Part 1. Water miscibility test of liquid organic chemical products;
- Part 2. Determination of dry residue after evaporation on a water bath for
volatile organic liquids;
- Part 3. Determination of permanganate-reducing substances;
- Part 4. Determination of trace sulfur in organic liquid products -
Microcoulometric method;
- Part 5. Determination of trace quantities of carbonyl compounds in
organic chemicals;
- Part 6. Determination of color for liquids - Tristimulus colorimetry.
This Part is the fifth part of GB/T 6324 and an integrated revision of GB/T
6324.5-1986 and GB/T 6324.6-1986.
The revision of this Part adopts the Standard of American Society for Testing
and Materials ASTM E 411-2005 Standard Test Method for Trace Quantities of
Carbonyl Compounds with 2,4-Dinitrophenylhydrazine (English version).
This Part was redrafted based on ASTM E 411-2005. Annex A lists the
comparison on clause number between this Part and ASTM E 411-2005.
Considering national conditions of China, this Part made some modifications
when adopting ASTM E 411-2005. The main difference is as follows.
- added determination of carbonyl compounds - volumetric method (4.2 of
this Part), so as to cooperate with the change of the method
determination range.
This Part replaces GB/T 6324.5-1986 Organic chemical products for industrial
use--Determination of content of carbonyl compounds present--Volumetric
method and GB/T 6324.6-1986 Organic chemical products for industrial use--
Determination of content of carbonyl compounds present in small amounts--
Photometric method.
Compared with GB/T 6324.5-1986 and GB/T 6324.6-1986, the main changes
are as follows.
- modified the name of this Part from “Organic chemical products for
industrial use--Determination of content of carbonyl compounds present”
Test method of organic chemical products –
Part 5. Determination of trace quantities of carbonyl
compounds in organic chemicals
WARNING This Part does not address all safety issues related to the use
of standards. It is user’s responsibility to take appropriate safety and
protective measures and to ensure compliance with the relevant national
regulations. See Clause 3 for information on safety and precautionary
measures.
1 Scope
This Part specifies the test methods for determination of carbonyl compounds
in organic chemical products. spectrophotometric method and volumetric
method.
This Part is applicable to the determination of carbonyl compounds in water-
soluble and alcohol-soluble organic chemical products. The spectrophotometric
method is applicable to the sample determination of which carbonyl compound
mass fraction is less than or equal to 0.01%. The volumetric method is
applicable to the sample determination of which carbonyl compound mass
fraction is greater than 0.01%.
2 Normative references
The following standards contain the provisions which, through reference in this
Part, constitute the provisions of this Part. For dated references, subsequent
amendments (excluding corrections) or revisions do not apply to this Part.
However, the parties who enter into agreement based on this Part are
encouraged to investigate whether the latest versions of these documents are
applicable. For undated reference documents, the latest versions apply to this
Part.
GB/T 601-2002 Chemical Reagent - Preparations of Standard Volumetric
Solutions
GB/T 603-2002 Chemical Reagent - Preparations of Reagent Solution for
Use in Test (ISO 6353-1.1982, NEQ)
GB/T 6682-2008 Water for analytical laboratory use - Specification and test
methods (eqv ISO 3696.1987)
GB/T 9725-2007 Chemical reagent - General rule for potentiometric
titration
3 Safety and preventative measures
3.1 Sampling safety shall be specified in the product standard according to
product characteristics.
3.2 Methanol is flammable. It may be on fire in distillation. So it should take
preventive measures. For example, inspect the flask for cracks; check the
device sealing and if it is equipped with protective cover, etc.. Sufficient
ventilation shall be provided so that the vapor concentration of the solvent
around the distillation is less than the explosion limit. And the solvent vapor
concentration in the entire working area is less than the threshold.
3.3 2,4-dinitrophenylhydrazine is easy to explode. Open flame or electric
spark can make it intense burning. Avoid heat sources during use.
4 Test method
4.1 General
Unless otherwise stated, only reagents identified as analytically pure and grade
3 water as specified in GB/T 6682-2008 can be used in the analysis.
The standard titration solutions, preparations and products used in the analysis,
in the absence of any other indication, shall be prepared in accordance with the
provisions of GB/T 601-2002 and GB/T 603-2002.
4.2 Spectrophotometric method
4.2.1 Methodology
The carbonyl compounds in the sample react with 2,4-dinitrophenylhydrazine
in acidic medium to generate 2,4-dinitrophenylhydrazone. 2,4-
dinitrophenylhydrazone reacts with potassium hydroxide, resulting in significant
red material. Measure the absorbance with a spectrophotometer at a
wavelength of 480 nm to obtain carbonyl compound content.
Equation.
where,
m1 - the value of the mass of the carbonyl compound checked on the standard
curve corresponding to the absorbance of the sample, in micrograms (μg);
m0 - the value of the mass of the carbonyl compound checked on the standard
curve corresponding to the blank absorbance, in micrograms (μg);
m - the mass of sample, in grams (g).
4.3 Volumetric method
4.3.1 Methodology
The carbonyl compound in the sample is reacted with hydroxylamine
hydrochloride. The resulting acid shall be indicated in bromophenol blue. Use
sodium hydroxide standard titration solution to titrate. Calculate the content of
carbonyl compound.
Equations.
RCHO + H2NOH•HCl = RCH = NOH + HCl + H2O
RCOR’ + H2NOH•HCl = RR’C = NOH + HCl + H2O
4.3.2 Reagents and solutions
4.3.2.1 95% ethanol
4.3.2.2 Hydroxylamine hydrochloride solution. 20 g/L
Weigh 4 g of hydroxylamine hydrochloride. Dissolve it in a 250 mL iodometric
volumetric flask containing 20 mL of water. Use 95% ethanol to dilute it to 200
mL. After inverse flowing on boiling water bath for 30 min, cool it to room
temperature. Add 5.0 mL of bromophenol blue indicator solution. Use sodium
hydroxide solution to neutralize so as to generate dichroic green. Prepare this
solution before use.
4.3.2.3 Sodium hydroxide standard titration solution. c(NaOH) = 0.1 mol/L
4.3.2.4 Sodium hydroxide solutio...