N-benzoyl-5'-O-(p,p'-dimethoxytrityl)-2'-deoxycytidine

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018-01-08 to 2018-04-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

GLP compliance:

no

Type of method:

effusion method: vapour pressure balance

Temp.:

20 °C

Vapour pressure:

< 0 Pa

Temp.:

25 °C

Vapour pressure:

< 0 Pa

Temp.:

50 °C

Vapour pressure:

< 0 Pa

The vapour pressure was measured in the temperature range of 70 °C to 120 °C. The temperature range was chosen due to preliminary information about the test item. A vapour pressure measurement at ambient temperature was not possible due to the low vapour pressure of the test item. The measured vapour pressures at the corresponding temperatures are listed in the Table 1. The amount of test item was determined before (0.4830 g) and after (0.4751 g) the vapour pressure measurement. After the measurement a mass loss of approx. 2% (w/w) was observed.

Table 1: Measured vapour pressures and corresponding temperatures

Temperature / °C	Vapour pressure / hPa
70	1.7 x 10E-5
80	1.7 x 10E-5
90	2.6 x 10E-5
100	3.0 x 10E-5
110	7.9 x 10E-6
120	5.2 x 10E-6

The test item showed an unsusual vapor pressure behaviour during the measurement. The data points measured between 70 °C and 100 °C showed a typical deviation most likely caused by volatile impurities at the beginning of the measurement. All other values were below the detection limit (1 x 10E-5 hPa). The unusual behaviour did not influence the final results.

The values for 20 °C, 25 °C and 50 °C were estimated using the Antoine equation. The detection limit at the highest measurement point (120 °C) was used for the calculation.

Conclusions:

The vapour pressure of the test item was determined according to the OECD guidline 104 by effusion method using a vapour pressure balance. The measured values were in the range of the detection limit and therefore the vapour pressures for 20 °C, 25 °C and 50 °C were estimated using the Antoine equation. Based on the measured vapour pressure at 120 °C, the following upper limit vapour pressures for the test item were calculated:
20 °C: < 4.6 x 10E-8 Pa;
25 °C: < 8.9 x 10E-8 Pa;
50 °C: < 1.8 x 10E-6 Pa.

Executive summary:

The vapour pressure of the test item was determined according to the OECD guidline 104 by effusion method using a vapour pressure balance. The measured values were in the range of the detection limit and therefore the vapour pressures for 20 °C, 25 °C and 50 °C were estimated using the Antoine equation. Based on the measured vapour pressure at 120 °C, the following upper limit vapour pressures for the test item were calculated:

20 °C: < 4.6 x 10E-8 Pa;

25 °C: < 8.9 x 10E-8 Pa;

50 °C: < 1.8 x 10E-6 Pa.

Description of key information

The vapour pressure of the test item was determined according to the OECD guidline 104 by effusion method using a vapour pressure balance. The measured values were in the range of the detection limit and therefore the vapour pressures for 20 °C, 25 °C and 50 °C were estimated using the Antoine equation. Based on the measured vapour pressure at 120 °C, the following upper limit vapour pressures for the test item were calculated:

20 °C: < 4.6 x 10E-8 Pa;

25 °C: < 8.9 x 10E-8 Pa;

50 °C: < 1.8 x 10E-6 Pa.