2-[3-[(4-amino-2-methylpyrimidin-5-yl)methyl]-4-methyl-1,3-thiazoniol-5-yl]ethyl dihydrogen diphosphate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15 Dec 2016 - 11 Jan 2017

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:

adopted in 1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

Version / remarks:

adopted in 2008

Deviations:

no

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Specific details on test material used for the study:

Storage conditions: ambient temperature (10 to 30 °C)

Temp.:

20 °C

Vapour pressure:

< 0 hPa

Temp.:

25 °C

Vapour pressure:

< 0 hPa

Temp.:

50 °C

Vapour pressure:

< 0 hPa

Results
The test item was degassed at 50 °C for 8 h before the measurement. The vapour pressure was measured in a range of 70 to 120 °C.

Table 1 – Meaured vapour pressure and corresponding temperatures

Temperature [°C]	Vapour pressure [hPa]
70	1.2E-05
80	3.5E-06
90	3.7E-06
100	5.2E-06
110	3.5E-06
120	2.1E-06

 

The data point measured at 70 °C was taken into account for further evaluations because it shows a typical deviation caused by volatile impurities at the beginning of a measurement. This behavior could be caused by water of crystallization. Data points measured between 80 and 120 °C were below the detection limit of 1.0E-05 hPa.

Vapour pressures obtained were not sufficiently high to extrapolate to 20, 25 and 50 °C. Therefore, these values were estimated using the Antoine equation (Eq. 2).

Constant C was assumed to be equal to 273.15 and constant B was -5000. The detection limit (1.0E-05 hPa) at the highest measuring point (120 °C) was used for the calculation as all measured vapour pressures were below the detection limit.

A = 1.0 log10^-5– [-5000/(273.15 + 120)] = 7.72

The vapour pressure at 20, 25 and 50 °C can then be calculated with the Antoine equation. Based on the detection limit and the highest measurement point at 120 °C, the following upper limit vapour pressures for the test item were calculated.

T [°C]	p [hPa]	p [Pa]
20	< 4.6E-10	< 4.6E-08
25	< 8.9E-10	< 8.9E-08
50	< 1.8E-08	< 1.8E-06

Description of key information

< 4.6E-10 hPa at 20 °C
< 8.9E-10 hPa at 25 °C
< 1.8E-08 hPa at 50 °C

(OECD 104, estimated using Antoine equation)

Additional information

Vapour pressures obtained were not sufficiently high to extrapolate to 20, 25 and 50 °C. Therefore, these values were estimated using the Antoine equation.