Desmedipham

Surface tension

Link to relevant study record(s)

Reference

Endpoint:

surface tension

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-09-04 to 2012-12-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.5 (Surface Tension)

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 115 (Surface Tension of Aqueous Solutions)

Deviations:

no

GLP compliance:

yes

Type of method:

ring method

Key result

Surface tension:

71.5 mN/m

Temp.:

20 °C

Remarks on result:

other: 90% saturated solution, dissolved in 7 mmol acetic acid to aid dissolution

The surface tension of an aqueous solution of Desmedipham, was determined according to the European Commission Council Regulation (EC) No. 440/2008, Annex, Part A, A.5. and OECD Test Guideline 115, ring method. The solubility of the test item in distilled water is below 1 g/L (5.6 mg/L at 20 °C, Ref. 1). Therefore, according to the OECD and EEC guidelines, the concentration of the test solutions used should be 90% of the saturation solubility. Due to the low water solubility some of the eluate fractions from the water solubility study (Ref. 1) were diluted to be used for the determination of the surface tension. The concentrations of the diluted solutions used were determined by HPLC analyses to be 5.1 mg/L and 4.9 mg/L respectively (approx. 90 % of the saturation concentration). Due to the lack of stability of the test item in solutions with pH values > pH 4 (Ref. 2), the test was performed in distilled water acidified with small amounts of acetic acid. The acetic acid concentration of the solutions being measured was 7.0 mmol/L.

Two independent determinations were performed in Firgure 1.

Surface tension of desmedipham (AE B038107), at 20 ± 0.5°C:

 

Conclusions:

72.39 mN/m at 20°C

Executive summary:

Test Guidelines: OECD Guideline 115 European Commission Council Regulation (EC) No 440/2008, Annex, Part A, method A.5. US EPA OCSPP Not Applicable

Results

The surface tension of an aqueous solution of Desmedipham, was determined according to the European Commission Council Regulation (EC) No. 440/2008, Annex, Part A, A.5. and OECD Test Guideline 115, ring method.

The solubility of the test item in distilled water is below 1 g/L (5.6 mg/L at 20 °C). Therefore, according to the OECD and EEC guidelines, the concentration of the test solutions used should be 90% of the saturation solubility.

Due to the low water solubility some of the eluate fractions from the water solubility study  were diluted to be used for the determination of the surface tension. The concentrations of the diluted solutions used were determined by HPLC analyses to be 5.1 mg/L and 4.9 mg/L respectively (approx. 90 % of the saturation concentration).

Due to the lack of stability of the test item in solutions with pH values > pH 4, the test was performed in distilled water acidified with small amounts of acetic acid. The acetic acid concentration of the solutions being measured was 7.0 mmol/L.

Two independent determinations were performed.

Surface tension of desmedipham, at 20 ± 0.5°C:

Blank solution (acetic acid, c = 7.0 mmol/L	Desmedipham, stabilised in acetic acid solution (7.0 mmol/L acetic acid)
	c = 5.0 mg/L (mean)
σ = 71.8 mN/m	σ = 71.5 mN/m

 

The surface tension of desmedipham, stabilised in acetic acid solution (c = 7.0 mmol/L) was 71.5 mN/nm and is therefore of the same order of magnitude as the surface tension of pure distilled water (σ = 72.75 mN/m).

Description of key information

The surface tension of desmedipham, stabilised in acetic acid solution (c = 7.0 mmol/L) was 71.5 mN/n

Key value for chemical safety assessment

Surface tension:

72.39