Maltose

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2017-05-02 to 2017-06-01

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: Knudsen cell

Key result

Temp.:

20 °C

Vapour pressure:

0.002 Pa

Temp.:

25 °C

Vapour pressure:

0.003 Pa

Remarks on result:

not measured/tested

Remarks on result:

not measured/tested

Table 1. Calculation Results Experiment 1

Experiment	1
Real Temperature in K	303.2
Real Temperature in °C	30.0
Date of Measurement	03.05.2017 11:40					04.05.2017 11:50			05.05.2017 11:45
Elapsed Time in s	82920					81600			82500
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	0.00117	yes		4.14E-03		0.00130	yes	4.68E-03	0.00095	yes	3.38E-03
Knudsen-cell 2	0.00095	yes		3.36E-03		0.00133	yes	4.79E-03	0.00094	yes	3.35E-03
Knudsen-cell 3	0.00143	yes		5.06E-03		0.00132	yes	4.75E-03	0.00096	yes	3.42E-03
Knudsen-cell 4	0.00149	yes		5.28E-03		0.00140	yes	5.04E-03	0.00090	yes	3.20E-03
Mean		yes		4.46E-03			yes	4.81E-03		yes	3.34E-03
Standard deviation:				8.82E-04				1.57E-04			9.36E-05
Mean of measured values:				4.205E-03
Standard deviation:				7.713E-04		RSD:	18.3%

Table 2. Calculation Results Experiment 2

Experiment	2
Real Temperature in K	318.2
Real Temperature in °C	45.0
Date of Measurement	09.05.2017 11:50					10.05.2017 11:50			11.05.2017 11:40
Elapsed Time in s	85500					83100			82800
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	0.00384	yes		1.35E-02		0.00351	yes	1.27E-02	0.00296	yes	1.08E-02
Knudsen-cell 2	0.00368	yes		1.29E-02		0.00340	yes	1.23E-02	0.00306	yes	1.11E-02
Knudsen-cell 3	0.00364	yes		1.28E-02		0.00335	yes	1.21E-02	0.00298	yes	1.08E-02
Knudsen-cell 4	0.00432	yes		1.52E-02		0.00382	yes	1.38E-02	0.00336	yes	1.22E-02
Mean		yes		1.36E-02			yes	1.27E-02		yes	1.12E-02
Standard deviation:				1.10E-03				7.63E-04			6.73E-04
Mean of measured values:				1.253E-02
Standard deviation:				1.209E-03		RSD:	9.7%

Table 3. Calculation Results Experiment 3

Experiment	3
Real Temperature in K	333.2
Real Temperature in °C	60.0
Date of Measurement	12.05.2017 12:10					16.05.2017 10:00			17.05.2017 10:45
Elapsed Time in s	84900					77400			82500
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	0.01104	yes		4.00E-02		0.00688	yes	2.74E-02	0.00321	yes	1.20E-02
Knudsen-cell 2	0.01077	yes		3.91E-02		0.00653	yes	2.60E-02	0.00343	yes	1.28E-02
Knudsen-cell 3	0.01075	yes		3.90E-02		0.00657	yes	2.61E-02	0.00359	yes	1.34E-02
Knudsen-cell 4	0.01234	yes		4.47E-02		0.00834	yes	3.32E-02	0.00342	yes	1.28E-02
Mean		yes		4.07E-02			yes	2.82E-02		no
Standard deviation:				2.74E-03				3.40E-03
Mean of measured values:				3.443E-02
Standard deviation:				8.869E-03		RSD:	25.8%

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

Experiment 4 (75 °C) showed no reproducible weight loss. Therefore, this experiment was not used for calculation and the measurement was stopped.

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

 

Table 1: Experimentally Determined Vapour Pressures

T	T	P	Stand. Dev. P	RSD P
°C	K	Pa	Pa	%
30.0	303.2	4.20E-03	7.71E-04	18.3%
45.0	318.2	1.25E-02	1.21E-03	9.7%
60.0	333.2	3.44E-02	8.87E-03	25.8%

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

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

The linear regression of log P vs. 1/T gave a correlation coefficient r of – 1.0000, showing good repeatability and precision. Therefore, the determination is considered as valid.

Parameter	Value
Slope	-3075.0
Intercept	7.7644
Correlation Coefficient r	-1.0000
Coefficient of Determination r^2	1.0000

Conclusions:

For the test item the following vapour pressures at 20°C and at 25°C were calculated from the regression equation:
for 20 °C: 1.88 * 1E-03 Pa
for 25 °C: 2.82 * 1E-03 Pa

Executive summary:

A key study was performed according to OECD TG 104 and Regulation (EC) No 440/2008 method A.4 in order to determine the vapour pressure of the test item at four different temperatures (30, 45, 60 and 75 °C) by using the effusion (Knudsen cell) method. Three experiments could be evaluated as they showed relevant and reproducible weight loss. All evaluated experiments showed good reproducibility, giving relative standard deviations of less than 26 % and perfect correlation. The vapour pressure of the test item was determined to be 1.88 * 10^-03 Pa (20 °C) and 2.82 * 10^-03 Pa (25 °C). The results of the test were considered as valid.

Description of key information

For the test item the following vapour pressures at 20 °C and at 25 °C were calculated from the regression equation:

for 20 °C: 1.88 * 10E-03 Pa

for 25 °C: 2.82 * 10E-03 Pa

Key value for chemical safety assessment

Vapour pressure:

0.002 Pa

at the temperature of:

20 °C

Additional information

A study was performed according to OECD TG 104 and Regulation (EC) No 440/2008 method A.4 in order to determine the vapour pressure of the test item at four different temperatures (30, 45, 60 and 75 °C) by using the effusion (Knudsen cell) method. All evaluated experiments showed good reproducibility, giving relative standard deviations of less than 26 % and perfect correlation. The vapour pressure of the test item was determined to be 1.88*10^-03 Pa (20 °C) and 2.82*10^-03 Pa (25 °C). The results of the test were considered as valid (reference 4.6-1).