ASTM D4954-89(1995)e1

Standard Test Method for Determination of Nitrilotriacetates in Detergents

SCOPE
1.1 This test method describes the determination of nitrilotriacetates (NTA) in detergents.
1.2 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: Historical
• Publication Date: 31-Dec-1994
• Technical Committee: D12 - Soaps and Other Detergents
• Drafting Committee: D12.12 - Analysis and Specifications of Soaps, Synthetics, Detergents and their Components

Relations

• Replaced By: ASTM D4954-89(2003) - Standard Test Method for Determination of Nitrilotriacetates in Detergents
• Effective Date: 26-May-1989

Standards Content (Sample)

NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: D 4954 – 89 (Reapproved 1995)
Standard Test Method for
Determination of Nitrilotriacetates in Detergents
This standard is issued under the fixed designation D 4954; 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.
e NOTE—Keywords were added editorially in February 1995.
1. Scope 5.6 Single Junction Reference Electrode (Orion Model 90-
01), filled with Orion 90-00-01 solution.
1.1 This test method describes the determination of nitrilo-
5.7 pH Combination Electrode.
triacetates (NTA) in detergents.
5.8 Burets, 10-mL, 25-mL, 50-mL.
1.2 This standard does not purport to address all of the
5.9 pH Meter, with millivolt capabilities.
safety concerns, if any, associated with its use. It is the
5.10 Automatic Titrator—may be substituted for 5.8 and
responsibility of the user of this standard to establish appro-
5.9.
priate safety and health practices and determine the applica-
5.11 Magnetic Stirrer/Hot Plate.
bility of regulatory limitations prior to use. For specific safety
5.12 Balance, with 1-mg sensitivity.
precautions, see 6.5.
6. Reagents
2. Summary of Test Method
6.1 Purity of Reagents—Reagent grade chemicals shall be
2.1 A known excess amount of copper nitrate solution is
used in all tests. Unless otherwise indicated, it is intended that
added to the detergent sample under controlled pH conditions.
all reagents shall conform to specifications of the Committee
The uncomplexed copper is back-titrated potentiometrically
on Analytical Reagents of the American Chemical Society,
with a standard NTA solution using a copper ion specific
where such specifications are available. Other grades may be
electrode. The millimoles of NTA in the sample are equivalent
substituted, provided it is first ascertained that the reagent is of
to the millimoles of copper added, less the millimoles of the
sufficiently high purity to permit its use without lessening the
NTA titrant.
accuracy of the determination.
3. Significance and Use
6.2 Disodium Ethylenediaminetetraacetate (EDTA), 0.1 M.
6.3 Nitric Acid, concentrated.
3.1 This test method is suitable in research, development,
6.4 Sodium Hydroxide, 50 % reagent solution.
and manufacturing control to monitor the level of NTA, a
6.5 Sodium Hydroxide, 20 % solution. Mix 40 g of the 50 %
sequestering agent, in powder and liquid detergents.
solution with 60 g of water. Cool. Wear a face shield during
3.2 Accurate determination of a sequestering agent is im-
mixing.
portant in evaluating cost and performance of detergent prod-
6.6 Cupric Nitrate, 0.1 M. Weigh (to the nearest 0.1 g) 6.3
ucts.
g of copper metal and transfer into a 600-mL beaker. Add about
4. Interferences 100 mL of water. Place a magnetic bar into the beaker and
place on a stirrer/hotplate. Add 30 mL of concentrated nitric
4.1 The presence of substances that will make copper
acid while stirring and heat gently. Stir until the copper metal
complex like citrate, formate, ethylenediaminetetraacetate, and
dissolves. Add more nitric acid if undissolved metal remains.
phosphonate, will interfere positively in the determination of
After dissolution, cool and transfer quantitatively to a 1-L
NTA.
volumetric flask. Dilute to the mark and mix the solution well.
5. Apparatus
6.6.1 Alternatively, weigh out (to the nearest 1 g) 23 g of
reagent grade cupric nitrate, 2 ⁄2 hydrate crystals, and transfer
5.1 Volumetric Flasks, 200-mL, 500-mL, 1000-mL.
to a 600-mL beaker. Add 400 mL of water. Stir to dissolve the
5.2 Beakers, 200-mL (tall form), 250-mL, 1000-mL.
crystals and add 5 mL of concentrated nitric acid. Transfer to
5.3 Pipets, 25-mL, 100-mL.
a 1-L volumetric flask, dilute to the mark and mix well.
5.4 Graduated Cylinders, 10-mL, 25-mL.
6.7 Trisodium Nitrilotriacetate Monohydrate (NTA), 0.3 M.
5.5 Copper Ion Electrode (Orion Model 94-29).
Weigh out (to the nearest 1 g) 41 g of NTA and dissolve in 400
This test method is under the jurisdiction of ASTM Committee D-12 on Soaps
and Other Detergents and is the direct responsibility of Subcommittee D12.12 on American Chemical Society, 1155 16th St., NW, Washington, DC 20036.
Analysis of Soaps and Synthetic Detergents. EDTA solution is available from J. T. Baker Inc., already standardized against
Current edition approved May 26, 1989. Published July 1989. NIST Reference Material Calcium Carbonate.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superceded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 4954
mL of water in a 600-mL beaker. Transfer to a 500-mL
where:
volumetric flask, dilute to the mark and mix well.
M 5 molarity of EDTA, and
6.8 Sodium Acetate Buffer Solution, Dissolve 68 g of re-
V 5 mL of EDTA.
agent sodium acetate, trihydrate, in 500 mL of water in a 1-L
beaker. Add 30 g of glacial acetic acid. Transfer to a 1-L 8. Standardization of NTA Solution
volumetric flask, dilute with water to the mark and mix well.
8.1 Proceed as for the standardization of the 0.1-M cupric
The pH of this solution should be 4.6 to 4.8.
nitrate; except in this case, the titrant will be the NTA solution
rather than EDTA solution. Use a 10-mL buret for the NTA
7. Standardization of 0.1-M Cupric Nitrate
titrant.
7.1 Add 50 mL of water into a 200-mL tall form beaker. Add
8.2 The first 6 mL can be added rapidly, then continue with
3 mL of concentrated nitric acid from a graduated cylinder.
0.5-mL increment additions. Determine the endpoint in accor-
Transfer by pipet a 25-mL aliquot of the cupric nitrate solution
dance with Table 1.
into the beaker.
8.3 Calculate the molarity of the NTA as follows:
7.2 Place the pH combination electrode into the solution.
Molarity of NTA 5 ~V 3 M!/V (2)
1 2
Adjust the pH to 1.0 to 1.1 by dropwise addition of 50 %
NaOH solution. About 2 mL may be re
...