Alkali metal tetrakis (perfluoro-alcoholato)metallate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May - July 2020

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:

March 2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: Knudsen cell

Specific details on test material used for the study:

Appearance: white powder

Test no.:

#1

Temp.:

60 °C

Vapour pressure:

0.015 Pa

Test no.:

#2

Temp.:

75 °C

Vapour pressure:

0.048 Pa

Test no.:

#3

Temp.:

90 °C

Vapour pressure:

0.152 Pa

Test no.:

#4

Temp.:

20 °C

Vapour pressure:

0 Pa

Remarks on result:

other: calculated from #1 - #3

Test no.:

#5

Temp.:

25 °C

Vapour pressure:

0.001 Pa

Remarks on result:

other: calculated from #1 - #3

FINDINGS

Sample Weights

The mass of sample in the respective cell is presented in the following table:

Table 1 a: Sample Weights

Parameter	Cell empty	Cell + test item	Cell + test item + cap	Test item
Unit	g	g	g	g
Knudsen-cell 1	2.57017	4.17170	4.38327	1.60153
Knudsen-cell 2	2.55472	4.04749	4.26063	1.49277
Knudsen-cell 3	2.55455	3.99813	4.21122	1.44358
Knudsen-cell 4	2.55702	3.95784	4.16966	1.40082

 

Measurement Data

The data of the evaluated experiments is presented in the following tables:

Table 2 a: Measurement Data Experiment 1, Nom. Temperature 30 °

Date and time START	12.05.2020 14:20	13.05.2020 13:30	14.05.2020 13:50
Date and time END	13.05.2020 12:30	14.05.2020 12:40	15.05.2020 11:15
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	4.29135	4.22722	4.21435
Knudsen-cell 2	4.16343	4.09634	4.08237
Knudsen-cell 3	4.11970	4.05587	4.04103
Knudsen-cell 4	4.08352	4.02395	4.01378

 

Table 2 b: Measurement Data Experiment 2, Nom. Temperature 45 °C

Date and time START	18.05.2020 11:45	19.05.2020 11:20	25.05.2020 08:45
Date and time END	19.05.2020 10:00	20.05.2020 12:40	26.05.2020 09:20
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	4.12297	4.11948	4.08572
Knudsen-cell 2	3.99163	3.97401	3.93667
Knudsen-cell 3	3.95363	3.94854	3.93293
Knudsen-cell 4	3.96229	3.93129	3.90187

 

Table 2 c; Measurement Data Experiment 3, Nom. Temperature 60 °

Date and time START	26.05.2020 14:05	27.05.2020 13:35	28.05.2020 14:50
Date and time END	27.05.2020 12:45	28.05.2020 13:50	29.05.2020 11:10
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	4.07604	4.06781	4.06284
Knudsen-cell 2	3.91779	3.91523	3.90959
Knudsen-cell 3	3.92102	3.91809	3.91143
Knudsen-cell 4	3.85322	3.84149	3.83264

 

Table 2 d: Measurement Data Experiment 4, Nom. Temperature 75 °C

Date and time START	02.06.2020 09:15	03.06.2020 12:10	04.06.2020 13:45
Date and time END	03.06.2020 11:05	04.06.2020 13:00	05.06.2020 13:00
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	3.17168	3.13818	3.12270
Knudsen-cell 2	3.15542	3.11957	3.10135
Knudsen-cell 3	3.12599	3.10068	3.08693
Knudsen-cell 4	3.12911	3.10160	3.08124

 

Table 2 e: Measurement Data Experiment 5, Nom. Temperature 90 °C

Date and time START	08.06.2020 10:10	09.06.2020 10:20	16.06.2020 10:40
Date and time END	09.06.2020 09:20	10.06.2020 12:45	17.06.2020 12:50
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	3.06560	3.04546	2.96818
Knudsen-cell 2	3.03502	3.02278	2.94860
Knudsen-cell 3	3.01923	3.00500	2.92959
Knudsen-cell 4	3.02415	3.00805	2.92838

 

Table 2 f: Measurement Data Experiment 6, Nom. Temperature 105 °C

Date and time START	17.06.2020 13:40	22.06.2020 10:30	23.06.2020 12:00
Date and time END	18.06.2020 12:45	23.06.2020 11:00	24.06.2020 11:20
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	2.95687	2.94359	2.94101
Knudsen-cell 2	2.94000	2.92762	2.92510
Knudsen-cell 3	2.92064	2.90959	2.90745
Knudsen-cell 4	2.91939	2.90704	2.90439

 

Table 2 g: Measurement Data Experiment 7, Nom. Temperature 120 °C

Date and time START	24.06.2020 11:55	29.06.2020 11:30	30.06.2020 12:00
Date and time END	25.06.2020 13:20	30.06.2020 11:15	01.07.2020 14:15
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	2.93718	2.92906	2.92762
Knudsen-cell 2	2.92145	2.91394	2.91241
Knudsen-cell 3	2.90399	2.89700	2.89538
Knudsen-cell 4	2.90111	2.89400	2.89254

 

Table 2 h: Measurement Data Experiment 8, Nom. Temperature 135 °C

Date and time START	01.07.2020 14:45	02.07.2020 12:00	06.07.2020 10:45
Date and time END	02.07.2020 11:30	03.07.2020 10:30	07.07.2020 09:10
Parameter	Weight m	Weight m	Weight m
Unit	g	g	g
Knudsen-cell 1	2.92487	2.92446	2.92444
Knudsen-cell 2	2.90980	2.90974	2.90975
Knudsen-cell 3	2.89301	2.89301	2.89302
Knudsen-cell 4	2.89011	2.89009	2.89008

 

Observations

At 60 °C: At the first measurement of experiment 3, all cells were slightly contaminated. Therefore, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, this measurement was not used for calculations.

 

At 60 °C: At the third measurement of experiment 3, the first cell were slightly contaminated. Therefore, the cell was meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, this measurement was not used for calculations.

 

At 75 °C: At the first measurement of experiment 4, all cells were slightly contaminated. Therefore, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, this measurement was not used for calculations.

 

At 75 °C: At the second measurement of experiment 4, the first and the second cells were slightly contaminated. Therefore, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, this measurement was not used for calculations.

 

At 90 °C: At the second measurement of experiment 5, all cells were slightly contaminat-ed. Therefore, the cells were meticulously cleaned and weighed. This weight was used as initial weight for the subsequent measurements. To avoid bias, this measurement was not used for calculations.

 

CALCULATION OF RESULTS

The vapour pressure was calculated using the following equation: p = m/KAtѴ(2πRT/M)

with

p = vapour pressure in Pa (to be calculated)

m = weight loss in kg (value given in tables above divided by 1000)

T = time in s (as given in tables above)

A = area of aperture in m² (7.85 * 10E-7 m² for d = 1 mm)

K = correction factor (0.909)

R = universal gas constant in J/Mol*K (8.314472)

T = temperature in K (as given in tables above)

M = molecular weight in kg/Mol (0.974)

 

The correction factor depends on the relation length/radius of the aperture of the Knudsen cell. The following factor is stated in the literature: Relation 0.2, K 0.909 (E.D.Cater, Ch.2A, Physicochem. Measurements in Metal Research, Part 1, R.A. Rapp, Ed., John Wiley, New York, 1970). With the chosen length of the aperture 0.1 mm and the chosen radius 0.5 mm, a relation of 0.2 was calculated, and a correction factor of 0.909 was chosen.

 

Calculation Results

All calculation results are given in the tables below.

In all tables, E-0X represents multiplication with 10-X. Experiment 1 - 2 and 6 - 8 (nominal temperature 30 – 45 and 105 - 130 °C) showed no reproducible weight loss. Therefore, they were not used for calculation.

Table 3 a: Calculation Results Experiment 3, Temperature in K 333.2 (60.0 °C)

Date of Measurement	27.05.2020 12:45			28.05.2020 13:50			29.05.2020 11:10
Elapsed Time in s	81600			87300			73200
Parameter	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no	Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.00968	yes	2.22E-02	0.00823	yes	1.77E-02	0.00497	yes	1.27E-02
Knudsen-cell 2	0.01888	yes	4.33E-02	0.00256	yes	5.49E-03	0.00564	yes	1.44E-02
Knudsen-cell 3	0.01191	yes	2.73E-02	0.00293	yes	6.28E-03	0.00666	yes	1.70E-02
Knudsen-cell 4	0.04865	yes	1.12E-01	0.01173	yes	2.52E-02	0.00885	yes	2.26E-02
Mean		no			yes	1.36E-02		yes	1.67E-02
Standard deviation:						9.47E-03			4.34E-03
Mean of measured values:		1.518E-02
Standard deviation:		2.162E-03	RSD:		14.2%

 

If “no” is stated in the respective column: measurement was not considered for the calculation of the mean.

 

Table 3 b: Calculation Results Experiment 4, Temperature in K 348.2 (75.0 °C)

Date of Measurement	03.06.2020 11:05			04.06.2020 13:00			05.06.2020 13:00
Elapsed Time in s	93000			89400			83700
Parameter	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no	Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.89116	yes	1.83E+00	0.03350	no		0.01548	yes	3.54E-02
Knudsen-cell 2	0.75417	yes	1.55E+00	0.03585	no		0.01822	yes	4.17E-02
Knudsen-cell 3	0.78544	yes	1.62E+00	0.02531	yes	5.42E-02	0.01375	yes	3.14E-02
Knudsen-cell 4	0.70353	yes	1.45E+00	0.02751	yes	5.89E-02	0.02036	yes	4.66E-02
Mean		no			yes	5.65E-02		yes	3.88E-02
Standard deviation:						3.33E-03			6.69E-03
Mean of measured values:		4.766E-02
Standard deviation:		1.257E-02	RSD:		26.4%

If “no” is stated in the respective column: measurement was not considered for the calculation of the mean.

 

Table 3 c: Calculation Results Experiment 5, Temperature in K 363.2 (90.0 °C)

Date of Measurement	09.06.2020 09:20			10.06.2020 12:45			17.06.2020 12:50
Elapsed Time in s	83400			95100			94200
Parameter	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure	Weight loss	to be used	Vapour pressure
Unit	g	yes/no	Pa	g	yes/no	Pa	g	yes/no	Pa
Knudsen-cell 1	0.05710	yes	1.34E-01	0.02014	yes	4.14E-02	0.07728	yes	1.60E-01
Knudsen-cell 2	0.06633	yes	1.55E-01	0.01224	yes	2.52E-02	0.07418	yes	1.54E-01
Knudsen-cell 3	0.06770	yes	1.59E-01	0.01423	yes	2.93E-02	0.07541	yes	1.57E-01
Knudsen-cell 4	0.05709	yes	1.34E-01	0.01610	yes	3.31E-02	0.07967	yes	1.65E-01
Mean		yes	1.45E-01		no			yes	1.59E-01
Standard deviation:			1.35E-02						4.96E-03
Mean of measured values:		1.523E-01
Standard deviation:		9.603E-03	RSD:		6.3%

If “no” is stated in the respective column: measurement was not considered for the calculation of the mean.

 

Evaluation

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

Table 4: Evaluation of Calculated Values

Parameter	T	Mean p	1/T	log p
Unit	K	Pa	1/K	log Pa
Values	333.2	1.52E-02	3.0012E-03	-1.8189
	348.2	4.77E-02	2.8719E-03	-1.3219
	363.2	1.52E-01	2.7533E-03	-0.8174

In this table, E-0X represents multiplication with 10-X.

 

Since the values were correlated by a linear relation, the data could be fitted by linear regression.

Table 4: Parameters of Linear Regression

Parameter	Value
Slope	-4036.8
Intercept	10.2882
Correlation Coefficient r	-0.9996
Coefficient of Determination r²	0.9992

 

RESULTS

The following vapour pressures were determined experimentally and considered as valid (mean and standard deviation given):

Table 5: Experimentally Determined Vapour Pressures

T	T	p	Stand. Dev. p	RSD p
°C	K	Pa	Pa	%
60.0	333.2	1.52E-02	2.16E-03	14.2%
75.0	348.2	4.77E-02	1.26E-02	26.4%
90.0	363.2	1.52E-01	9.60E-03	6.3%

In this table, E-0X represents multiplication with 10-X.

Stand. Dev. = Standard Deviation; RSD = Relative Standard Deviation

 

For the test item AM(pfa)4, the following vapour pressures at 20 °C and at 25 °C were calculated from the regression equation:

Vapour pressure at 20 °C: 3.30 * 10-04 Pa

Vapour pressure at 25 °C: 5.61 * 10-04 Pa

The linear regression of log p vs. 1/T gave a correlation coefficient r of - 0.9996, showing good repeatability and precision. Therefore, the determination is considered as valid.

Positive Control: For Diethylphthalate the following vapour pressure was determined and compared with recommended value: Vapour pressure (positive control) at 30 °C: 1.96*10-1 Pa

Criterion for the vapour pressure of the positive control at 30 °C: 0.44*10-1 - 2.44*10-1 Pa

The vapour pressure met the validity criteria. Therefore, the study can be considered as valid.

Conclusions:

Vapour pressure for AM(pfa)4 at 20 °C: 0.000330 (3.30 * 10E-04) Pa and at 25 °C: 0.000561 (5.61 * 10E-04) Pa

Executive summary:

The vapour pressure of the test item AM(pfa)4 was determined at eight different temperatures (30, 45, 60, 75, 90, 105, 120 and 135 °C) according to OECD 104 resp. EU A.4 using the effusion method (weight loss). Experiment 1 – 2 and 6 - 8 (nominal temperature 30 - 45 °C and 105 – 135 °C) showed no reproducible weight loss and were not used for calculation. 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.

Three experiments could be evaluated as they showed relevant and reproducible weight loss. All evaluated experiments showed good repeatability, giving relative standard deviations of less than 26.4 % (limit value from the guideline 30 %) and good correlation. Therefore, the result of the test can be considered valid.

For the test item AM(pfa)4, the following vapour pressures at 20 °C and at 25 °C were calculated from the regression equation established in this experiment:

Vapour pressure at 20 °C: 3.30 * 10-04 Pa

Vapour pressure at 25 °C: 5.61 * 10-04 Pa

Description of key information

Vapour pressure for AM(pfa)4 at 20 °C: 0.000330 (3.30 * 10E-04) Pa and at 25 °C: 0.000561 (5.61 * 10E-04) Pa

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C