ASTM E2313-22

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2313 − 21a E2313 − 22
Standard Test Method for
Aldehydes in Mono-, Di-, and Triethylene Glycol (using
Spectrophotometry)
This standard is issued under the fixed designation E2313; 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 (´) indicates an editorial change since the last revision or reapproval.
1. Scope*
1.1 This test method describes the spectrophotometric determination of total aldehyde content in mono-, di-, and triethylene glycol
(MEG, DEG, and TEG). Alkoxyalcohols (hemiacetals), if present, are co-determined, whereas dialkoxyalkanes (acetals), if
present, are not. The results provide a measure of the purity of the sample with respect to total aldehyde content.
1.2 This test method is applicable to samples with total aldehyde concentration (as acetaldehyde) to 50 mg/kg or 35 mg ⁄kg (as
formaldehyde). The limit of detection (LOD) is 0.4 mg ⁄kg and the limit of quantitation is 1.2 mg/kg.
NOTE 1—LOD and LOQ were calculated using the lowest level sample in the ILS.
1.3 The following applies for the purposes of determining the conformance of the test results using this test method to applicable
specifications, results shall be rounded off in accordance with the rounding-off method of Practice E29.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.5 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use. For specific hazard statements, see Section 8 and 7.1.1 – 7.1.6.
1.6 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D2194 Test Method for Concentration of Formaldehyde Solutions
D6809 Guide for Quality Control and Quality Assurance Procedures for Aromatic Hydrocarbons and Related Materials
E29 Practice for Using Significant Digits in Test Data to Determine Conformance with Specifications
This test method is under the jurisdiction of ASTM Committee D16 on Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsibility of
Subcommittee D16.14 on Alcohols & Glycols.
Current edition approved Nov. 1, 2021Sept. 1, 2022. Published December 2021September 2022. Originally approved in 2003. Last previous edition approved in 2021 as
E2313 – 21.E2313 – 21a. DOI: 10.1520/E2313-21A.10.1520/E2313-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E2313 − 22
E180 Practice for Determining the Precision of ASTM Methods for Analysis and Testing of Industrial and Specialty Chemicals
(Withdrawn 2009)
E275 Practice for Describing and Measuring Performance of Ultraviolet and Visible Spectrophotometers
E288 Specification for Laboratory Glass Volumetric Flasks
E300 Practice for Sampling Industrial Chemicals
E969 Specification for Glass Volumetric (Transfer) Pipets
E1547 Terminology Relating to Industrial and Specialty Chemicals
2.2 Other Document:
Manufacturer’s Instruction Manual of Spectrophotometer
3. Terminology
3.1 See Terminology E1547 for definitions of terms used in this test method.
4. Summary of Test Method
4.1 The total aldehyde content of the sample is determined spectrophotometrically. The aldehydes present are reacted with excess
3-methyl-2-benzothiazolinone hydrazone (MBTH) to form azines. An aqueous solution of iron (III) chloride is added, causing the
oxidation of the excess MBTH to a reactive cation, which reacts with the previously formed azines producing bluish-green cations.
Acetone or methanol is added to stop the oxidation reaction, to mask the excess MBTH and to obtain a clear solution. The
absorbance of the test solution is measured spectrophotometrically at 635 nm. The amount of aldehyde present in the test solution
is derived from a previously prepared calibration graph. The aldehyde content of the sample, expressed as either acetaldehyde or
formaldehyde, is calculated from the data obtained.
5. Significance and Use
5.1 Knowledge of the total aldehyde content of MEG is required to establish whether the product meets the requirements of its
quality specifications.
6. Apparatus
6.1 Spectrophotometer, suitable for measurement at a wavelength of 635 nm, provided with cells with a pathlength of 10 mm.
NOTE 2—Further information on spectrophotometers can be obtained from Practice E275.
6.2 Analytical Balance, readable to 0.1 mg, calibrated. Recalibrate or verify at regular intervals.
6.3 Stopwatch, measuring accuracy 61 s or better. Verify at regular intervals.
6.4 Buret, calibrated, 100 mL, with a 50- or 75-mL reservoir on top of a lower portion calibrated in 0.1-mL divisions. A
PTFE-fluorocarbon resin stopcock is suitable for this purpose. Recalibrate or verify at regular intervals.
6.5 Adjustable Volume Dispensing Pipette(s), capable of dispensing volumes in the range 1.00 to 5.00 mL, with suitable disposable
pipette tips. It is recommended to verify the capacity of the pipette(s) at regular intervals.
6.6 Glassware:
NOTE 3—In cases where volumetric glassware is to be used, it shall conform to Grade (or Class) A specifications as described in, for example,
Specification E288 for volumetric flasks, or Specification E969 for one-mark pipettes.
7. Reagents
7.1 Purity of Reagents—Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the
The last approved version of this historical standard is referenced on www.astm.org.
E2313 − 22
committee on Analytical Reagents of the American Chemical Society where such specifications are available. Other grades may
be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy
of the determination.
7.1.1 Acetone (2-propanone), A.R. minimum purity 99.99 % (V/V). (Warning—Acetone is highly flammable. Keep container in
a well-ventilated place. Keep away from sources of ignition. Do not breathe vapor. Take precautionary measures against static
discharges.)
7.1.2 Formaldehyde, A.R., 36 to 40 % mass formaldehyde solution (Formalin). (Warning—Formaldehyde is classified as a
human carcinogen. Formaldehyde is toxic by inhalation, in contact with skin and if swallowed. Causes burns. Possible risks of
irreversible effects. May cause sensitization by skin contact. In case of contact with eyes, rinse immediately with plenty of water
and seek medical advice. Wear suitable protective clothing, gloves and eye/face protection. In case of accident or if you feel unwell,
seek medical advice immediately. Use only in well ventilated areas.)
7.1.3 Hydrochloric Acid, A.R., concentrated [36 % mass]. (Warning—Hydrochloric Acid is toxic by inhalation. Causes severe
burns. Keep container in a well-ventilated place. In case of contact with eyes, rinse immediately with plenty of water and seek
medical advice. Wear suitable protective clothing, gloves and eye/face protection. In case of accident or if you feel unwell, seek
medical advice immediately.)
7.1.4 Iron (lll) Chloride, (FeCl ·6H O), A.R. (Warning—Iron (III) Chloride causes burns. Avoid contact with skin and eyes. In
3 2
case of contact with eyes, rinse immediately with plenty of water and seek medical advice. Take off immediately all contaminated
clothing. Wear eye/face protection. If swallowed, seek medical advice immediately and show the container or label.)
7.1.5 Methanol, A.R. minimum purity 99.99 % (V/V). (Warning—Methanol is highly flammable. Toxic by inhalation and
ingestion. Keep container in a well-ventilated place. Keep container tightly closed when not in use. Keep away from sources of
ignition. Avoid contact with skin. In case of accident or if you feel unwell, seek medical advice immediately (show the label where
possible.)
7.1.6 3-Methyl-2-Benzothiazolinone Hydrazone Hydrochloride (MBTH). (Warning—MBTH is toxic if swallowed. Irritating to
eyes. Keep locked up. Avoid contact with skin and eyes. In case of contact with eyes, rinse immediately with plenty of water and
seek medical advice. This material and its container must be disposed of in a safe way. Wear suitable protective clothing. In case
of accident or if you feel unwell, seek medical advice immediately. If swallowed, seek medical advice immediately and show the
container or label.)
7.2 Water, reagent water conforming to Type I or II of Specification D1193.
7.3 Solutions:
7.3.1 Standard Formaldehyde Solution, 8.0 μg/mL, aqueous. Determine the exact concentration (c ) of an A.R. 36 to 40 % mass
formaldehyde solution (Warning—See 7.1.2.) according to Test Method D2194, expressing the result in g/100 mL. Weigh
approximately 2.0 to 2.2 g (m ) of the formaldehyde solution to the nearest 0.1 mg, into a 100-mL volumetric flask. Make up to
the mark with water and mix thoroughly. Pipette 1.0 mL of this solution into a 1-L volumetric flask. Make up to the mark with
water and mix thoroughly. Transfer this solution to a brown bottle with screw cap. Calculate the exact formaldehyde content of
this solution (c ), in μg/mL, by means of the following equation:
m 3c
1 1
c , µg/mL 5 (1)
where:
c = concentration of concentrated formaldehyde solution used, g/100 mL, and
m = mass of concentrated formaldehyde solution taken, g.
The concentrated and diluted formaldehyde solutions are stable in excess of six months if stored at room temperature. Do not
store in a refrigerator. Prepare fresh solutions every six months.
ACS Reagent Chemicals, Specifications and Procedures for Reagents and Standard-Grade Reference Materials, American Chemical Society, Washington, DC. For
suggestions on the testing of reagents not listed by the American Chemical Society, see Analar Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and
the United States Pharmacopeia and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
E2313 − 22
7.3.2 Hydrochloric Acid, 50 % (V/V). Dilute one volume of A.R. concentrated hydrochloric acid (Warning—See 7.1.3.) with one
volume of water.
7.3.3 Iron (III) Chloride Solution, 0.3 % mass, aqueous. Dissolve 5 g of A.R. iron (III) chloride. 6H O (Warning—See 7.1.4.) in
water, adding 1 or 2 drops of A.R. concentrated hydrochloric acid to stabilize solution (Warning—See 7.1.3.) and dilute to 1 L
with water. Prepare a fresh solution daily.
7.3.4 Methyl-2-benzothiazolone Hydrazone Solution (MBTH solution),0.4 % mass, aqueous. Dissolve 400 6 1 mg of MBTH
hydrochloride (Warning—See 7.1.6.) in water in a 100-mL volumetric flask. Make up to the mark and mix thoroughly. Prepare
a fresh solution daily.
7.4 Reagents, as described in Test Method D2194, for the standardization of formaldehyde solution (see 7.3.1).
7.4.1 Sodium Sulfite Solution, 12.5 % mass, aqueous. Dissolve 125 g of anhydrous sodium sulfite (Na SO ) in water and dilute
2 3
to 1 L.
NOTE 4—Sodium sulfite gradually oxidizes to sodium sulfate on exposure to air and therefore should be kept in a tightly closed container. For best results
freshly prepared reagent should be used.
7.4.2 Sulfuric Acid, 0.5 mol/L (1.0 N). Prepare and standardize sulfuric acid (H SO ) against 0.5 mol/L (0.5 N) sodium hydroxide
2 4
(NaOH) solution which has been standardized against potassium acid phthalate to a thymolphthalein end point.
7.4.3 Thymolphthalein Indicator, 0.1 % mass, alcohol solution. Dissolve 1.0 g of thymolphthalein in 100 mL of methanol, ethanol,
or isopropanol and dilute to 1 L with additional alcohol.
7.5 Ethylene Glycol Quality Control Sample—It is recommended to select an Ethylene Glycol sample (fiber grade MEG, DEG or
TEG), similar to the product being analyzed and to use it as a quality control sample (Warning—See 8.28.3.). To this end, ensure
to obtain a sufficient amount and store it in such a way that it is stable for a known period of time and use it as such during this
period of time only. For more details, see 16.1.2.
8. Hazards
8.1 Consult current OSHA regulations and supplier’s Safety Data Sheets and local regulations for all materials used in this test
method.
8.2 Note health and safety warnings in Section 7.
8.3 Ethylene Glycol—Although (mono-, di-, and tri-) ethylene glycol in general is not classified as dangerous or flammable and
is not expected to impose a health hazard when used under normal conditions, it is recommended to avoid inhalation and contact
with skin and eyes. Wear suitable protective clothing and gloves. Do not breathe gas, fumes, vapor, or spray. Use only in well
ventilated areas. In case of contact with eyes rinse with plenty of water and seek medical advice.
8.4 Formaldehyde is classified as a human carcinogen.
9. Sampling, Test Specimens, and Test Units
9.1 Follow the relevant instructions for sampling as given in Practice E300.
10. Preparation of Apparatus
10.1 Spectrophotometer—Check the performance of the spectrophotometer at regular intervals according to
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