Sodium 3-amino-2,4,6-triiodobernzoate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

21 March 2001 to 22 March 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

Principles of method if other than guideline:

Information on vapor pressure of the test substance was to be obtained as a contribution to the Schering project. Ecotoxicological Evaluation of Starting Materials, Intermediates and Drug Substances. The project is part of the Freiwillige Selbstverpflichtung der deutschen chemischen Industrie für die Erfassung und Bewertung von Stoffen (voluntary self commitment of the German chemical industry to catalogue and evaluate chemicals) as promoted by the VCI (Verband der Chemischen Industrie).

GLP compliance:

not specified

Type of method:

effusion method: Knudsen cell

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 3-amino-2,4,6-triiodobernzoate

EC Number:

614-015-0

Cas Number:

67031-56-5

Molecular formula:

C7-H3-I3-N-O2.Na

IUPAC Name:

Sodium 3-amino-2,4,6-triiodobernzoate

Test material form:

solid: bulk

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Wirkstoffbetrieb F, Schering AG, Bergkamen, Batch Number: 60707022

Results and discussion

Vapour pressure

Key result

Test no.:

#1

Temp.:

ca. 25 °C

Vapour pressure:

< 0.001 Pa

Any other information on results incl. tables

The EC Testing Guideline A.4 recommends the use of the vapor pressure balance for the range from 1⋅10^-3Pa to 1 Pa.

 

Inserting the vapor pressure value of 1⋅10-3 Pa in Equ.1 (see chapter 4) an evaporation rate of 0.014 μg/s can be calculated.

 

Equ.1 

P = K⋅φ⋅(T/M)^0.5

 

P = vapour pressure at a given temperature (Pa)

φ = evaporation rate (μg · s-1)

K = apparatus constant = 0.2285/(q · sin2α)

q = area of the aperture (mm2)

α = angle of the vapour jet, escaping from the cell

T = temperature (K)

M = molecular weight (g/mol)

The measured evaporation rate of the mixture (< 1.5⋅10-3 μg/s) at 25°C is significantly below the calculated value. Therefore, it can be assumed that the vapor pressure of the mixture and consequently of the test substance is lower than the lower limit of the measuring range recommended by the EC Testing Guideline.

 

p₂₅< 10^-3Pa (10^-5mm Hg)

 

In addition the mass spectra of the vapor escaping from the Knudsen cell show only masses m/e < 200 indicating that impurities with low molecular weights were evaporated from the mixture.

Applicant's summary and conclusion

Conclusions:

The measured vapor pressure of the test substance by the Knudsen cell was < 10^-3 Pa (10^-5 mm Hg) at 25°C.

Executive summary:

The vapor pressure of the test substance was determined using a screening method based on the detection of the evaporation rate from a Knudsen cell of a vapor pressure balance at 25°C. Since simplified experimental conditions are also acceptable within the scope of this project, the test substance was mixed with four other compounds. From all five test substances low or very low vapor pressures, based on the study director’s experience, were expected. For this reason the experiments consisted in the measurement of the evaporation rate of the mixture from a Knudsen cell a 25°C. Since the evaporation rate of the mixture was below the value derived from the lower limit of the vapor pressure range recommended for the use of a vapor pressure balance (10^-3Pa, EC Testing Guideline A.4) it can be assumed that the vapor pressure of the mixture is lower than 10^-3Pa. Considering this fact, the vapor pressure of the single compounds in the mixture has also to be lower than 10^-3Pa. Therefore, the vapor pressure of the test substance can be estimated to be at 25°C: p₂₅< 10^-3Pa.