Reaction mass of sodium hydrogen N-(1-oxooctadecyl)-L-glutamate and sodium hydrogen N-(1-oxohexadecyl)-L-glutamate

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24/04/2008-19/09/2008

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in compliance with GLP and agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

yes

Remarks:

The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used

Principles of method if other than guideline:

Deviation:
The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used. Once calibrated, the balance and ring assembly used in this test give a direct reading for the surface rension that is within the required accuracy (+/- 0.5 mN/m); this is as a result of the reduced ring dimensions.
This deviation has been considered not to have affected the integrity of the study.

GLP compliance:

yes (incl. QA statement)

Remarks:

Date of Signature: 15/10/2007; Date of Inspection: 21/08/2007

Type of method:

ring method

Surface tension:

50.5 mN/m

Temp.:

22 °C

Remarks on result:

other: The surface tension of a solution containing 0.300 g/l of constituent 1 and 7.71 x 10-2 g/l of constituent 2 was determined

Sample solution concentration

The mean peak areas for each component relating to the standard and sample solutions are shown in the following tables:

component 1

Solution	MeanArea
Standard 46.2 mg/l	650.138
Standard 44.8 mg/l	616.894
Sample	471.565
Sample solution concentration = 0.272 g/l
Sample solution concentration (corrected for recovery) = 0.300 g/l

component 2

Solution	MeanArea
Standard 89.3 mg/l	1.158 x 10^3
Standard 86.7 mg/l	1.105 x 10^3
Sample	49.955
Sample solution concentration = 3.11 x 10^-2g/l
Sample solution concentration (corrected for recovery) = 7.71 x 10^-2g/l

 

Calibration factor (f)

The readings, temperatures and the corresponding calibration factors for glass double-distilled water are shown in the following table:

Reading (mN/m)	Temperature (ºC)	Literature Value (mN/m)	Calibration Factor
72.5	22.0	72.41	0.999
72.5	22.0	72.41	0.999
72.5	22.0	72.41	0.999
72.5	22.0	72.41	0.999
72.5	22.0	72.41	0.999
72.5	22.0	72.41	0.999
Mean Calibration Factor = 0.999

Sample solution readings

The readings, times and temperatures for the sample solution are shown in the following table:

Time (mins)	Reading (mN/m)	Temperature (ºC)
63	50.5	22.0
69	50.5	22.0
79	50.5	22.0
85	50.5	22.0
91	50.5	22.0

Mean reading                    :   50.5 mN/m
Surface tension                  = reading x calibration factor
                                         = 50.5 x 0.999
                                         = 50.5 mN/m
Temperature                      :   22.0 ± 0.5ºC
pH of sample solution        :   6.3

Validation

See Water Solubility Section.

 

Conclusions:

The surface tension of a solution with a loading rate of 1.162 g/L (resulting in 0.300 g/l of constituent 1 and 7.71 x 10^-2 g/l of constituent 2) has been determined to be 50.5 mN/m at 22.0°C ± 0.5°C. The test material is considered to be a surface-active material.

Executive summary:

The surface tension of the test material was determined using a White Electrical Institute interfacial tension balance and a procedure based on the ISO 304 ring method. With the exception of the following deviation, the experimental procedure used complied with that specified in Method A5 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

1) The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used. Once calibrated, the balance and ring assembly used in this test give a direct reading for surface tension that is within the required accuracy (± 0.5 mN/m); this is as a result of the reduced ring dimensions.

This deviation has been considered not to have affected the integrity of the study.

 

The surface tension of a solution with a loading rate of 1.162 g/L (resulting in 0.300 g/l of constituent 1 and 7.71 x 10^-2 g/l of constituent 2) has been determined to be 50.5 mN/m at 22.0°C ± 0.5°C. The test material is considered to be a surface-active material.

Description of key information

50.5 mN/m at 22 °C with a loading rate of 1.162 g/L (resulting in 0.300 g/L of constituent 1 and 7.71 x 10^-2 g/L of constituent 2), EU Method A.5, Butler & White (2008)

Key value for chemical safety assessment

Surface tension:

50.5

in mN/m at 20°C and concentration in mg/L:

1 162

Additional information

The surface tension of the test material was determined in the key study (Butler & White 2008) using a White Electrical Institute interfacial tension balance and a procedure based on the ISO 304 ring method. With the exception of the following deviation, the experimental procedure used complied with that specified in Method A5 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

The surface tension result was not corrected using the Harkins-Jordan correction table as the correction is not applicable to the apparatus used. Once calibrated, the balance and ring assembly used in this test give a direct reading for surface tension that is within the required accuracy (± 0.5 mN/m); this is as a result of the reduced ring dimensions. This deviation has been considered not to have affected the integrity of the study.

The study was therefore assigned a reliability score of 1 in accordance with the principles for assessing data quality as outlined in Klimisch et al. (1997). 

The surface tension of a solution with a loading rate of 1.162 g/L (resulting in 0.300 g/L of constituent 1 and 7.71 x 10 ^-2 g/L of constituent 2) has been determined to be 50.5 mN/m at 22.0 ± 0.5 °C. The test material is considered to be a surface-active material.