Reaction mass of calcium 2,6-bis(3-carboxylatopropanamido)hexanoate and isomers of calcium amino-(3-carboxylatopropanamido)hexanoate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2 September 2016 - 25 October 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Version / remarks:

23 March

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

24. August 2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7950 (Vapor Pressure)

Version / remarks:

August 1996

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: Knudsen cell

Key result

Temp.:

20 °C

Vapour pressure:

0 Pa

Remarks on result:

other: calculated from the regression equation

Key result

Temp.:

25 °C

Vapour pressure:

0 Pa

Remarks on result:

other: calculated from the regression equation

The measured values for temperature and vapour pressure were evaluated as follows:

Parameter	T	Mean P	1/T	Log P
Unit	K	Pa	1/K	Log Pa
Value	378.2	4.56E-04	2.6441E-03	-3.3409
	393.2	1.39E-03	2.5432E-03	-2.8567
	408.2	3.51E-03	2.4498E-03	-2.4550
	423.2	7.76E-03	2.3629E-03	-2.1099

The graph with log P vs. 1/T was plotted. Since the values were correlated by a linear relation, the data could be fitted by linear regression.

Parameter	Value
Slope	-4376.6
Intercept	8.2508
Correlation Coefficient r	-0.9991
Coefficient of Determination r2	0.9982

Vapour pressure was examined at nine different temperatures. Four temperatures could be evaluated as they showed reproducible weight loss:

Experiment	T	Mean P	Stand.Dev.P	RSD P
No.	K	Pa	Pa	%
6	378.2	4.56E-04	3.49E-05	7.6 %
7	393.2	1.39E-03	2.53E-04	18.2 %
8	408.2	3.51E-03	8.13E-05	2.3 %
9	423.2	7.76E-03	3.46E-04	4.5 %

In this table, E-0X represents multiplication with 10^-x. Stand. Dev. = Standard Deviation; RSD = Relative Standard Deviation

Conclusions:

The vapour pressure of the test item was calculated to be 2.1E-7 Pa at 20 °C and 3.73E-7 Pa at 25 °C, respectively.

Executive summary:

A study was conducted according to OECD TG 104, EU method A.4 and EPA OPPTS 830.7950 to determine the vapour pressure of the test item at nine different temperatures (30, 45, 60, 75, 90, 105, 120, 135 and 150 °C) using the effusion method (Knudsen cell). All measured values showed good reproducibility, giving relative standard deviations of less than 18.2 %, and good correlation. Therefore, the result of the test according to the guideline criteria was considered to be valid. Experiment 1 - 5 (nominal temperature 30 - 90 °C) yielded no relevant or reproducible weight loss. These temperatures were not used for calculation cause at the first experiments the volatile components evaporated and the main constituents were determined at the following experiments. When visible contaminations, caused by explosive evaporation of the test item, were observed, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, these measurements were not used for calculations. Four temperatures could be evaluated as they showed reproducible weight loss. The vapour pressure was calculated using the linear regression equation of the Log P versus 1/T function. The vapour pressure of the test item was calculated to be 2.1E-7 Pa at 20 °C and 3.73E-7 Pa at 25 °C, respectively.

Description of key information

The vapour pressure of the test item was calculated to be 2.1E-7 Pa at 20 °C and 3.73E-7 Pa at 25 °C, respectively.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C

Additional information

A study was conducted according to OECD TG 104, EU method A.4 and EPA OPPTS 830.7950 to determine the vapour pressure of the test item at nine different temperatures (30, 45, 60, 75, 90, 105, 120, 135 and 150 °C) using the effusion method (Knudsen cell). All measured values showed good reproducibility, giving relative standard deviations of less than 18.2 %, and good correlation. Therefore, the result of the test according to the guideline criteria was considered to be valid. Experiment 1 - 5 (nominal temperature 30 - 90 °C) yielded no relevant or reproducible weight loss. These temperatures were not used for calculation cause at the first experiments the volatile components evaporated and the main constituents were determined at the following experiments. When visible contaminations, caused by explosive evaporation of the test item, were observed, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, these measurements were not used for calculations. Four temperatures could be evaluated as they showed reproducible weight loss. The vapour pressure was calculated using the linear regression equation of the Log P versus 1/T function. The vapour pressure of the test item was calculated to be 2.1E-7 Pa at 20 °C and 3.73E-7 Pa at 25 °C, respectively.