Standard Test Method for Purity of Aldehydes and Ketones

SCOPE
1.1 This test method covers the determination of the purity of certain commercially available aldehydes and ketones.  
1.2 In addition to all aldehydes and ketones, all compounds such as vinyl alkyl ethers, acetals, and ketals, that hydrolyze under the conditions of the reaction to form free carbonyl groups, react with the reagent and consequently interfere. Water, alcohols, saturated esters, and hydrocarbons do not react with the reagent, but large amounts of inert organic solvents are undesirable because of the effect on the indicator.  
1.3  This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.  For specific hazard statements, see Section 7.
1.4 For hazard information and guidance, see the supplier's Material Safety Data Sheet.

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Publication Date
31-Dec-1995
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ASTM D2192-96(2000) - Standard Test Method for Purity of Aldehydes and Ketones
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:D2192–96 (Reapproved 2000)
Standard Test Method for
Purity of Aldehydes and Ketones
This standard is issued under the fixed designation D 2192; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
NH OH·HCl 1 ~HOCH CH ! N→ (1)
1. Scope
2 2 2 3
1.1 This test method covers the determination of the purity NH OH 1 ~HOCH CH ! N·HCl
2 2 2 3
of certain commercially available aldehydes and ketones.
The free hydroxylamine reacts with the aldehyde or ketone
1.2 In addition to all aldehydes and ketones, all compounds
to form the corresponding oxime.
such as vinyl alkyl ethers, acetals, and ketals, that hydrolyze
RR C50 1 NH OH→ RR C5H5NOH 1 H O, (2)
1 2 1 2
under the conditions of the reaction to form free carbonyl
groups, react with the reagent and consequently interfere.
where:
Water,alcohols,saturatedesters,andhydrocarbonsdonotreact
R = alkyl group and
withthereagent,butlargeamountsofinertorganicsolventsare R = alkyl group or hydrogen.
undesirable because of the effect on the indicator.
The amount of hydroxylamine consumed, which is deter-
1.3 This standard does not purport to address all of the mined by titration of the excess base with standard sulfuric
safety concerns, if any, associated with its use. It is the
acid, is a measure of the aldehyde or ketone originally present.
responsibility of the user of this standard to establish appro- 3.2 Since the determination is based on an acidimetric
priate safety and health practices and determine the applica-
titration, a suitable correction must be applied if the sample is
bility of regulatory limitations prior to use. For specific hazard not neutral to bromophenol blue indicator.
statements, see Section 7.
4. Significance and Use
1.4 For hazard information and guidance, see the supplier’s
Material Safety Data Sheet. 4.1 This test method provides a measurement of purity
(assay) of aldehydes and ketones. The results of these mea-
2. Referenced Documents
surements can be used for specification acceptance.
2.1 ASTM Standards: 4.2 The precision of this test method is applicable only to
D 268 Guide for Sampling and Testing Volatile Solvents
material having a purity of 98 to 100 %.
and Chemical Intermediates for Use in Paint and Related
2 5. Apparatus
Coatings and Materials
D 1193 Specification for Reagent Water 5.1 Pressure Bottle, 200 to 350-mLcapacity, with lever type
E 200 Practice for Preparation, Standardization, and Stor- closure and made of heat-resistant glass.
age of Standard and Reagent Solutions for Chemical 5.2 Container for Pressure Bottle—Asuitable safety device
Analysis to contain the pressure bottle.Ametal container with a hinged
E 222 Test Methods for Hydroxyl Groups by Acetic Anhy- top and perforated bottom, a strong synthetic fabric or canvas
dride Acetylation bag, or a safety shield may be used.
5.3 Ampoule, 1 or 2-mL capacity.
3. Summary of Test Method
5.4 Weighing Pipet, Lunge or similar type.
3.1 Hydroxylamine hydrochloride is converted in part to
5.5 Burets, 50-mL capacity.
free hydroxylamine by reaction with a known amount of 5.6 Transfer Pipet, 50-mL capacity.
aqueous triethanolamine.
5.7 Glass Rod, 8-mm, several pieces approximately 1 in.
long.
5.8 Boiling Water Bath.
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and Related Coatings, Materials, andApplications and is the direct responsibility of
6. Reagents and Materials
Subcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.
Current edition approved May 10, 1996. Published July 1996. Originally 6.1 Purity of Reagents—Reagent grade chemicals shall be
published as D 2192 – 63. Last previous edition D 2192 – 89.
used in all tests. Unless otherwise indicated, it is intended that
Annual Book of ASTM Standards, Vol 06.04.
all reagents shall conform to the specifications of the Commit-
Annual Book of ASTM Standards, Vol 11.01.
tee onAnalytical Reagents of theAmerican Chemical Society,
Annual Book of ASTM Standards, Vol 15.05.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D2192
where such specifications are available. Other grades may be substantially pure material, weigh the specimen to the nearest
used, provided it is first ascertained that the reagent is of 0.1 mg, using the amount and procedure specified in Table 1.
sufficiently high purity to permit its use without lessening the 7.6.1 Warning: Acetaldehyde is a highly volatile, flam-
accuracy of the determination. mable material; observe all necessary safety precautions.
6.2 Purity of Water—Unless otherwise indicated, references Handle samples only in a fume hood that is free from open
to water shall be understood to mean reagent water conforming flames, electric heaters, and other sources of ignition. Cool all
to Type IV of Specification D 1193. samples in an ice bath before the containers are opened. Weigh
6.3 Bromophenol Blue Indicator (0.04 % Alcoholic the acetaldehyde in a sealed glass ampoule. The actual proce-
Solution)—Dissolve 0.04 g of bromophenol blue (tetrabro- dure for filling and sealing the ampoule will vary somewhat
mophenolsulfonphthalein)in100mLofmethylalcohol.Titrate with the type of ampoule being used. One convenient method
this solution with 0.1 N sodium hydroxide (NaOH) solution to is to pack commercially available ampoules in powdered, solid
a reddish-bronze color. If an off-color is obtained at this point, carbon dioxide, introduce the specimen by means of a chilled
it is probably due to the age of the indicator and fresh indicator hypodermic syringe, and seal the ampoule with a gas torch.
should be used to prepare a new solution. 7.7 If a sealed glass ampoule is used to weigh the specimen,
6.4 Cylinder Nitrogen. add several pieces of 8-mm glass rod and shake the bottle
6.5 Hydroxylamine Hydrochloride, Standard (0.5 N Alco- vigorously to break the ampoule.
holic Solution)—Dissolve 35 g of hydroxylamine hydrochlo- 7.8 React the solutions at room temperature or at 98°C
ride (NH OH · HCl) in 150 mLof water and dilute to 1 Lwith according to the directions in Table 1.
99 % isopropanol. 7.8.1 Reaction at 98°C (Warning—See 7.8.1.1.)—Place
6.6 Isopropanol (99 %). the specimen and blank bottles as close together as possible in
6.7 Sulfuric Acid, Standard (0.5 N)—Prepare and standard- a boiling water bath maintained at least at 98°C for the time
ize 0.5 N sulfuric acid (H SO ) in accordance with Practice specifiedinTable1.Maintainsufficientwaterinthebathtojust
2 4
E 200, Sections 24 through 27. cover the liquid in the bottles. Remove the bottles from the
6.8 Triethanolamine, Standard (0.5 N Aqueous Solution)— bath after the specified time and allow them to cool in air to
Dissolve 65 mL (74 g) of 98 % triethanolamine in water and room temperature.When the bottles have cooled, remove them
dilute to 1 L with water. Adjust the normality of this solution from the safety device and continue as described in 7.9.
so that it is slightly below the normality of the H SO being 7.8.1.1 Warning: Enclose each bottle securely in a suitable
2 4
used. container (metal or strong fabric) to restrain fragments of glass
should the pressure bottle rupture.
7. Procedure
7.8.2 Reaction at Room Temper
...

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