6-Amino-5-chloro-2-cyclopyrimidine-4-carboxylic acid

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2007-08-08 to 2007-10-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 104 (Vapour Pressure Curve)

GLP compliance:

yes (incl. QA statement)

Remarks:

Food and Consumer Product Safety Authority (WMA), Den Haag, The Netherlands / National GLP Compliance Monitoring Authority, New Delhi, India

Type of method:

gas saturation method

Key result

Temp.:

20 °C

Vapour pressure:

0 Pa

Key result

Temp.:

25 °C

Vapour pressure:

0 Pa

The test item transported by the nitrogen gas was adsorbed only in the first layer of silica gel in the sorbent tubes for all the tests. The second layer did not contain any test item. These results demonstrate that the sorbent material selected for the study was efficient in trapping all transported test item. A component related to the test item eluting near the retention time of IN-LXT69 (approximately 9.2 minutes) was observed in the first sorbent trap attached to the saturator columns incubated at 40, 45 and 50 °C. This component was not observed either in the method validation samples or in the extract of the fortified silica traps. In addition, test item was observed on the coated glass beads at the conclusion of the saturator column incubation indicating that the test item remained in excess for the duration of the study. Based on this data, this component related to the test item had no effect on the vapour pressure determination of the test item.

 

Temperature	Vapour pressure (P) of test item [Pa]
	50 mL/min	40 mL/min	30 mL/min	Mean
40.0 °C (313.15 K)	2.4561E-6	1.4547E-6	2.4225E-6	2.1111E-6
45.0 °C (318.15 K)	9.703E-7	1.2615E-6	1.0080E-6	1.0799E-6
50.0 °C (323.15 K)	1.8020E-6	0.7338E-6	0.9723E-6	1.1694E-6
20 °C (293.15 K)*: 6.9215E-6 Pa (5.192E-8 mm Hg or Torr) 25 °C (298.15 K)*: 4.9113E-6 Pa (3.684E-8 mm Hg or Torr)

* The vapour pressure at 20 and 25 °C presented above was calculated using the linear regression equation, which resulted from plotting VP (vapour pressure in Pa) versus temperature (1/T) in Kelvin.

 

Vapour Pressure at 40 °C

The duration of the main test conducted at 40 °C was approximately 28 days. The vapour pressure of the test item was determined at three different gas flow rates. The vapour pressure of the test item was 2.4561E-6, 1.4547E-6, and 2.4225E-6 Pa at 50, 40, and 30 mL/min flow rates, respectively. These results clearly indicate that the nitrogen gas was completely saturated with test item at all three flow rates for the duration of the test. The mean value of vapour pressure was 2.1111E10-6 Pa.

 

Vapour Pressure at 45 °C

The duration of the main test conducted at 45 °C was approximately 12 days. The vapour pressure of the test item was determined at three different gas flow rates. The vapour pressure of the test item was 9.703E-7, 1.2615E-6 and 1.0080E-6 Pa at 50, 40, and 30 mL/min carrier gas flow rate, respectively. These results clearly indicate that the carrier gas was completely saturated with test item at all three flow rates for the duration of the test. The mean value of vapour pressure was 1.0799E-6 Pa.

 

Vapour Pressure at 50 °C

The duration of the main test conducted at 50 °C was approximately 13 days. The vapour pressure of the test item was determined at three different gas flow rates. The vapour pressure of the test item was 1.8020E-6, 0.7338E-6 and 0.9723E-6 Pa at 50, 40, and 30 mL/min carrier gas flow rate, respectively. These results clearly indicate that the carrier gas was completely saturated with test item at all three flow rates for the duration of the test. The mean value of vapour pressure was 1.1694E-6 Pa.

 

Vapour Pressure at 20 and 25 °C

A vapour pressure curve was plotted using inverse value of the experimental temperature in K (1/T) on the X-axis and Log P (where P = vapour pressure in Pa) determined at that temperature) on the Y-axis. The vapour pressure of the test item at 20 and 25 °C was calculated using the slope (2613.1) and the intercept (-14.073) of the regression line (r =0.8119). The vapour pressure of the test item at 20 and 25 °C was 6.9215E-6 Pa (5.192E-8 mm Hg or Torr) and 4.9113E-6 Pa (3.684E-8 mm Hg or Torr), respectively.

Conclusions:

The vapour pressure of the substance was determined to be 6.9215E-6 Pa at 20 °C and 4.9113E-6 Pa at 25 °C (OECD Guideline 104, gas saturation method)

Description of key information

6.9215E-6 Pa at 20 °C and 4.9113E-6 Pa at 25 °C (OECD Guideline 104, gas saturation method)

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C

Additional information

The vapour pressure values at 20 and 25 °C were extrapolated from the vapour pressure curve.