Reaction mass of copper digluconate, sodium sulphate and copper sulphate

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29.10.2008 - 30.10.2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

GLP compliance:

yes (incl. QA statement)

Type of method:

static method

Specific details on test material used for the study:

The sample was placed on a rotary evaporator at 40°C until no more water evaporated; the sample was spread onto trays and placed in an oven at 40°C for approximately 6 days with frequent agitation. The partially wet sample was removed from the trays and frozen. Whilst frozen the sample was ground to a fine powder then spread on trays and placed back into the oven at 40°C for 24 hours.

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0.64 mBar

Test no.:

#1

Temp.:

20 °C

Vapour pressure:

0.575 mBar

Test no.:

#1

Temp.:

29.9 °C

Vapour pressure:

2.5 mBar

Test no.:

#1

Temp.:

60 °C

Vapour pressure:

53.6 mBar

Key result

Test no.:

#2

Temp.:

20 °C

Vapour pressure:

0.08 mBar

Test no.:

#2

Temp.:

20 °C

Vapour pressure:

0.099 mBar

Test no.:

#2

Temp.:

30 °C

Vapour pressure:

0.379 mBar

Test no.:

#2

Temp.:

39.9 °C

Vapour pressure:

2.6 mBar

Test no.:

#2

Temp.:

50 °C

Vapour pressure:

20.7 mBar

Run 1

The dried and ground sample was placed under vacuum for approximately 6 days. The sample was ground again, and 5.8 g placed in a round bottom flask. The sample degassed overnight. Vacuum at start of analysis was 0.0021 mbar. The first reading was taken after 4 hours of equilibration which is longer than typical.

Run 2

5.1g of the twice ground sample was placed in a round bottom flask and degassed for approximately 134 hrs. Vacuum at start of analysis was 0.0018mbar. It is suspected that

the poor linearity of the data collected is due to residual water in the dried test material. It is considered unlikely that extending the time on vacuum would improve the result.

Conclusions:

< 8 Pa at 20°C.

Executive summary:

The two test runs provided significantly different results, despite extended degassing to eliminate trapped air and volatile components. Volatile components/impurities can significantly impact the vapour pressure, even by several magnitudes. Due to the nature of the sample and its behaviour during the testing, it was considered that the extrapolated values would provide more accurate and valuable data than the direct readings. The lower result was 8 Pa, and the higher was 64 Pa. It is suspected that the variation in results is due to trapped moisture, therefore the result has been reported as < 8 Pa.

Description of key information

< 8 Pa at 20°C

Key value for chemical safety assessment

Vapour pressure:

8 Pa

at the temperature of:

20 °C