ASTM D4954-89(2017)

Standard Test Method for Determination of Nitrilotriacetates in Detergents

SIGNIFICANCE AND USE
3.1 This test method is suitable in research, development, and manufacturing control to monitor the level of NTA, a sequestering agent, in powder and liquid detergents.  
3.2 Accurate determination of a sequestering agent is important in evaluating cost and performance of detergent products.
SCOPE
1.1 This test method describes the determination of nitrilotriacetates (NTA) in detergents.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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 safety precautions, see 6.5.

General Information

• Status: Published
• Publication Date: 31-Dec-2016
• ICS: 71.100.40 - Surface active agents
• Technical Committee: D12 - Soaps and Other Detergents
• Drafting Committee: D12.12 - Analysis and Specifications of Soaps, Synthetics, Detergents and their Components

Relations

• Replaces: ASTM D4954-89(2009) - Standard Test Method for Determination of Nitrilotriacetates in Detergents
• Effective Date: 01-Jan-2017

Overview

ASTM D4954-89(2017): Standard Test Method for Determination of Nitrilotriacetates in Detergents is an internationally recognized analytical procedure published by ASTM International. The standard outlines the precise method for quantifying nitrilotriacetates (NTA), an important sequestering agent, present in powder and liquid detergent formulations. This method ensures laboratories and manufacturers can accurately assess and control NTA content, helping to optimize detergent performance and manage associated costs.

NTA serves as a chelating agent, commonly used to enhance cleaning efficacy by binding metal ions in water. Its accurate determination is essential in product development, quality control, and regulatory compliance within the detergents industry.

Key Topics

• Scope: The method applies to both powder and liquid detergents and mandates the use of SI units.
• Significance: Quantitative NTA analysis supports research, formulation optimization, and cost-effective manufacturing.
• Apparatus and Reagents: Utilizes standard laboratory equipment, including volumetric flasks, titration burets, copper ion electrodes, and pH meters, alongside reagent-grade chemicals.
• Interferences: The procedure’s accuracy can be affected by other chelating substances such as citrate, formate, ethylenediaminetetraacetate (EDTA), and phosphonates, which may also react with copper ions.
• Summary of Method: The test involves adding excess copper nitrate to a detergent sample. The unreacted copper is back-titrated potentiometrically with an NTA standard using copper ion-selective electrodes. This provides a direct measure of the NTA present in the test sample.
• Safety Considerations: Users must establish all necessary safety and health protocols due to the chemicals involved and possible regulatory obligations.

Applications

The ASTM D4954-89(2017) standard is widely utilized in:

• Manufacturing Quality Control: Ensuring that the NTA content in detergents meets formulation specifications, avoiding under- or over-dosing of sequestering agents.
• Product Development and Research: Assessing the influence of NTA concentration on detergent efficacy and cost efficiency.
• Regulatory Compliance: Demonstrating adherence to environmental and safety standards concerning chelating agents in consumer products.
• Process Optimization: Supporting efficient formulation adjustments based on precise NTA concentration data to maintain product performance.
• Third-Party Testing and Validation: Providing a standardized measurement method for industry laboratories and certification bodies.

Related Standards

Organizations working with NTA in detergents may also consult:

• ASTM D1963 - Standard Test Method for Ethylenediaminetetraacetic Acid (EDTA) in Detergents
• ASTM D5233 - Standard Test Method for Biological Active Compounds in Detergents
• ISO 4316 - Surface Active Agents - Determination of Primary Biodegradability

These standards, along with ASTM D4954-89(2017), form a comprehensive toolkit for laboratory testing, regulatory scrutiny, and quality assurance in the detergent manufacturing sector.

By following ASTM D4954-89(2017), laboratories and manufacturers benefit from reliable, repeatable, and internationally recognized procedures for NTA determination, supporting product excellence and regulatory readiness.

Standards Content (Sample)

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.
Designation: D4954 −89 (Reapproved 2017)
Standard Test Method for
Determination of Nitrilotriacetates in Detergents
This standard is issued under the fixed designation D4954; 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 5. Apparatus
1.1 This test method describes the determination of nitrilo- 5.1 Volumetric Flasks, 200-mL, 500-mL, 1000-mL.
triacetates (NTA) in detergents.
5.2 Beakers, 200-mL (tall form), 250-mL, 1000-mL.
1.2 The values stated in SI units are to be regarded as
5.3 Pipets, 25-mL, 100-mL.
standard. No other units of measurement are included in this
5.4 Graduated Cylinders, 10-mL, 25-mL.
standard.
5.5 Copper Ion Electrode (Orion Model 94-29).
1.3 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5.6 Single Junction Reference Electrode (Orion Model 90-
responsibility of the user of this standard to establish appro-
01), filled with Orion 90-00-01 solution.
priate safety and health practices and determine the applica-
5.7 pH Combination Electrode.
bility of regulatory limitations prior to use. For specific safety
5.8 Burets, 10-mL, 25-mL, 50-mL.
precautions, see 6.5.
5.9 pH Meter, with millivolt capabilities.
2. Summary of Test Method
5.10 Automatic Titrator—may be substituted for 5.8 and
2.1 A known excess amount of copper nitrate solution is
5.9.
added to the detergent sample under controlled pH conditions.
5.11 Magnetic Stirrer/Hot Plate.
The uncomplexed copper is back-titrated potentiometrically
5.12 Balance, with 1-mg sensitivity.
with a standard NTA solution using a copper ion specific
electrode. The millimoles of NTAin the sample are equivalent
6. Reagents
to the millimoles of copper added, less the millimoles of the
NTA titrant.
6.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated, it is intended that
3. Significance and Use
all reagents shall conform to specifications of the Committee
on Analytical Reagents of the American Chemical Society,
3.1 This test method is suitable in research, development,
where such specifications are available. Other grades may be
and manufacturing control to monitor the level of NTA, a
substituted, provided it is first ascertained that the reagent is of
sequestering agent, in powder and liquid detergents.
sufficiently high purity to permit its use without lessening the
3.2 Accurate determination of a sequestering agent is im-
accuracy of the determination.
portant in evaluating cost and performance of detergent prod-
6.2 DisodiumEthylenediaminetetraacetate(EDTA), 0.1 M.
ucts.
6.3 Nitric Acid, concentrated.
4. Interferences
6.4 Sodium Hydroxide, 50 % reagent solution.
4.1 The presence of substances that will make copper
6.5 SodiumHydroxide, 20 % solution. Mix 40 g of the 50 %
complex like citrate, formate, ethylenediaminetetraacetate, and
solution with 60 g of water. Cool. Wear a face shield during
phosphonate, will interfere positively in the determination of
mixing.
NTA.
6.6 Cupric Nitrate, 0.1 M. Weigh (to the nearest 0.1 g) 6.3
gofcoppermetalandtransferintoa600-mLbeaker.Addabout
100 mL of water. Place a magnetic bar into the beaker and
This test method is under the jurisdiction of ASTM Committee D12 on Soaps
and Other Detergents and is the direct responsibility of Subcommittee D12.12 on
Analysis and Specifications of Soaps, Synthetics, Detergents and their Components.
Current edition approved Jan. 1, 2017. Published February 2017. Originally American Chemical Society, 1155 16th St., NW, Washington, DC 20036.
approved in 1989. Last previous edition approved in 2009 as D4954-89(2009). DOI: EDTA solution is available from J. T. Baker Inc., already standardized against
10.1520/D4954-89R17. NIST Reference Material Calcium Carbonate.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4954 − 89 (2017)
A
TABLE 1 Determination of Inflection Point
place on a stirrer/hotplate. Add 30 mL of concentrated nitric
acid while stirring and heat gently. Stir until the copper metal
NOTE 1—Volume of NTArequired to react with 25 mLof cupric nitrate
dissolves. Add more nitric acid if undissolved metal remains. solution (0.0972 M).
After dissolution, cool and transfer quantitatively to a 1-L NTA, mL mV, (+)
volumetric flask. Dilute to the mark and mix the solution well.
0 303
1.00 300
6.6.1 Alternatively, weigh out (to the nearest 1 g) 23 g of
2.00 297
reagent grade cupric nitrate, 2 ⁄2 hydrate crystals, and transfer
3.00 294
to a 600-mL beaker. Add 400 mL of water. Stir to dissolve the 4.00 291
5.00 287
crystals and add 5 mL of concentrated nitric acid. Transfer to
6.00 283
a 1-L volumetric flask, dilute to the mark and mix well.
7.00 275 ∆mV ∆(∆mV)
7.50 270
6.7 Trisodium Nitrilotriacetate Monohydrate (NTA), 0.3 M.
Weigh out (to the nearest 1 g) 41 g of NTAand dissolve in 400 V 8.00 260 36 D
1 1
mL of water in a 600-mL beaker. Transfer to a 500-mL
V 8.50 214 25 D
2 2
volumetric flask, dilute to the mark and mix well.
9.00 193
6.8 Sodium Acetate Buffer Solution, Dissolve 68 g of re-
9.50 188
agent sodium acetate, trihydrate, in 500 mL of water in a 1-L
10.00 186
beaker. Add 30 g of glacial acetic acid. Transfer to a 1-L A
End Point = V + [(V −V )×(D /(D +D ))].
1 2 1 1 1 2
= 8.00 + [(8.50 − 8.00) × (36 ⁄(36 + 25))].
volumetric flask, dilute with water to the mark and mix well.
= 8.00 + [(0.5) × (0.59)].
The pH of this solution should be 4.6 to 4.8.
=8.00+0.30.
= 8.30 mL.
Then,
7. Standardization of 0.1-M Cupric Nitrate
25.00 mL cupric nitrate3 0.0972 M
7.1 Add50mLofwaterintoa200-mLtallformbeaker.Add Molarity of NTA5 5 0.2928 M
8.30 mL NTA
3 mL of concentrated nitric acid from a graduated cylinder.
Transfer by pipet a 25-mLaliquot of the cupric nitrate solution
into the beaker.
7.2
...