Registration Dossier

Administrative data

Endpoint:
surface tension
Type of information:
experimental study
Adequacy of study:
key study
Study period:
07 and 09 April 2008
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Study conducted in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affcet the quality of relevant results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2008

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method A.5 (Surface Tension)
Deviations:
no
Principles of method if other than guideline:
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. certificate)
Remarks:
Date of inspection: 21/08/07 Date of signature: 15/10/07
Type of method:
ring method

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Sponsor's identification : VCBK3810
Description : black powder
Lot number : N006746
Date received : 25 February 2008
Storage conditions : room temperature, in the dark

Results and discussion

Surface tension
Surface tension:
68.6 mN/m
Temp.:
21.5 °C
Remarks on result:
other: The surface tension of 90% saturation concentration solution of test material has been determined to be 68.6 mN/m

Any other information on results incl. tables

 Results:

 Sample solution concentration:

The mean peak areas relating to the standard and sample solutions are shown in the following table:

Solution

MeanArea

Group 1

Group 2

Standard 20.1 mg/l

350.744

193.802

Standard 20.2 mg/l

362.307

200.545

Matrix blank

None detected

None detected

Sample A

353.466

75.262

Sample B

349.371

70.530

Mean sample solution

3.98 x 10-2g/l

1.49 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

73.5

21.6

72.5

0.986

72.5

21.6

72.5

1.000

73.0

21.6

72.5

0.993

73.0

21.6

72.5

0.993

73.5

21.6

72.5

0.986

73.0

21.6

72.5

0.993

73.0

21.6

72.5

0.993

73.0

21.6

72.5

0.993

73.0

21.6

72.5

0.993

Mean Calibration Factor = 0.992                   

 

 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)

156

68.5

21.6

166

69.5

21.6

179

68.5

21.6

189

68.5

21.6

200

68.5

21.6

208

68.5

21.6

218

68.5

21.6

230

68.5

21.6

Mean reading                    :   68.6 mN/m
Surface tension                  = reading x calibration factor
                                         = 68.6 x 0.992
                                         = 68.1 mN/m
Temperature                      :   21.5 ± 0.5ºC
pH of sample solution        :   6.7

Validation:

The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0 to 50 mg/l. This was satisfactory with a correlation coefficient of > 0.997 being obtained for all groups of analyte monitored.

Discussion:

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

It is evident from the information obtained in the hydrolysis test (see Section 10) and data relating to the pH of the test material in water that negligible hydrolysis of the sample solution occurred during the course of the surface tension test.

In the absence of definitive purity values for the test material, all calculated concentration values have been reported as equivalent test material concentrations. That is, the concentration calculated for any individual group/component is equivalent to that specified concentration of test material having been successfully dissolved. The test material has been quantified separately for the two distinct groups of peaks eluting at approximately 5 minutes and 10 minutes respectively.

On initial assessment, the analytical results for the surface tension sample solution were seemingly high when compared to the water solubility definitive test samples solutions values. However on applying Grubb’s outlier test to the surface tension equivalent test material concentration for both the group 1 components and group 2 components (as defined above) the values were not identified as statistically significant using P = 0.05, even when correcting for the 90% dilution of the sample solution. Therefore the results were confirmed as being within the anticipated statistical spread for the procedure applied to the analysis of the water solubility sample solutions.

Applicant's summary and conclusion

Conclusions:
The surface tension of 90% saturation concentration solution of test material has been determined to be 68.6 mN/m at 21.5 ± 0.5°C. The test material is considered not to be a surface-active material. On analysis the sample solution was determined to contain components in the first eluting group equivalent to 3.98 x 10-2 g/l of test material in solution and components in the second eluting group equivalent to 1.49 x 10-2 g/l of test material in solution.
Executive summary:

Surface Tension: 68.6 mN/m (90% saturated solution) at 21.5 ± 0.5°C, using a ring method based on ISO 304, Method A5 of Commission Directive 92/69/EEC. The test material is considered not to be a surface-active material. On analysis the sample solution was determined to contain components in the first eluting group equivalent to 3.98 x 10-2g/l of test material in solution and components in the second eluting group equivalent to 1.49 x 10-2g/l of test material in solution.