Sodium naphthalene-2-carboxylate

Surface tension

Administrative data

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Testing was conducted between 16 May 2008 and 13 June 2008.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

yes

Principles of method if other than guideline:

The determination was carried out 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.

GLP compliance:

yes (incl. QA statement)

Remarks:

The work described was performed in compliance with UK GLP standards (Schedule 1, Good Laboratory Practice Regulations 1999 (SI 1999/3106 as amended by SI 2004/0994)).

Type of method:

ring method

Test material

Test material information

Constituent 1

Reference substance name:

Sodium naphthalene-2-carboxylate

EC Number:

700-038-4

Cas Number:

17273-79-9

Molecular formula:

C11 H7 Na O2

IUPAC Name:

Sodium naphthalene-2-carboxylate

Results and discussion

Surface tension

Surface tension:

71.9 mN/m

Temp.:

21.4 °C

Conc.:

1 g/L

Any other information on results incl. tables

Results

    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	21.4	72.50	1.000
72.5	21.4	72.50	1.000
72.5	21.4	72.50	1.000
72.5	21.4	72.50	1.000
72.5	21.4	72.50	1.000
72.5	21.4	72.50	1.000
Mean Calibration Factor = 1.000

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)
106	71.5	21.4
113	72.0	21.4
121	72.0	21.4
131	72.0	21.4
144	72.0	21.4

Mean reading                     :    71.9 mN/m
Surface tension                   =  reading x calibration factor
                                          =  71.9 x 1.000
                                          =  71.9mN/m
Temperature                       :    21.4 ± 0.5ºC
pH of sample solution         :    6.7

         Discussion

Substances showing a surface tension lower than 60 mN/m should be regarded as being surface-active.

Conclusion

The surface tension of a 1.00 g/l solution of test material has been determined to be 71.9 mN/m at 21.4 ± 0.5°C.  The test material is considered not to be a surface-active material.

Applicant's summary and conclusion

Conclusions:

The surface tension of a 1.00 g/l solution of test material has been determined to be 71.9 mN/m at 21.4 ± 0.5°C. The test material is considered not to be a surface-active material.

Executive summary:

The surface tension of a 1.00 g/l solution of test material Na-Na in project number 1307 -0436 has been determined to be 71.9 mN/m at 21.4 ± 0.5°C. The test material is considered not to be a surface-active material.The determination was carried out 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.