D-cellobiose

Vapour pressure

Link to relevant study record(s)

Reference

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1999

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test:
The Knudsen effusion technique was applied
- Short description of test conditions:
The substance effuses through a small pinhole, of known area, in another wise sealed cell. The measurement of vapor pressure involves determining the rate of mass loss from the effusion cell. Measurements were made under isothermal conditions. The temperature was measured with a precision of (0.1 K, by a thermocouple in contact with an aluminum capsule that almost completely surrounds the effusion cell. The mass loss rate was continuously recorded using a Cahn 2000 recording electrobalance. The back-pressure in the TGA system was maintained at 10-5 Pa, which has been noted to be sufficient so as to provide accuracy in the 10-4 Pa range of vapor pressures. Further details of the technique are provided elsewhere (Oja and Suuberg, 1997).
- Parameters analysed / observed: mass loss rate

GLP compliance:

no

Type of method:

effusion method: Knudsen cell

Specific details on test material used for the study:

Cellobiose is clearly identified by the information provided in the publication:
- molecular formula: C12H22O11
- molecular weight: 342.3
- CAS Reg. No.: 528-50-7

Key result

Temp.:

474.23 K

Vapour pressure:

ca. 0.003 Pa

The publication expresses the vapour pressure as a function of the temperature for the measure temperature range, i.e 474 to 488 K.

The function is: ln(VP[Pa]) = 70.3 - 36264/T[K], with VP being the vapour pressurer in Pa and T the tempertaure in Kelvin. Using this function to extrapolate the vapour pressure to 20°C results in a vapour pressure of 6.4e-24 Pa.

 

Conclusions:

In a study using the Knudsen effusion technique for the low vapor pressure cellobiose, a vapor pressure of 0.0026 Pa at 474.23 K, i.e. 201.08°C, was determined. This results allows to conclude that the vapor pressure of cellobiose is 0 at ambient temperature.

Executive summary:

In a study using the Knudsen effusion technique for the low vapor pressure cellobiose, a vapor pressure of 0.0026 Pa at 474.23 K, i.e. 201.08°C, was determined. This results allows to conclude that the vapor pressure of cellobiose is 0 at ambient temperature.

Description of key information

In a study using the Knudsen effusion technique for the low vapor pressure cellobiose, a vapor pressure of 0.0026 Pa at 474.23 K, i.e. 201.08°C, was determined. This results allows to conclude that the vapor pressure of cellobiose is 0 at ambient temperature.

Key value for chemical safety assessment

Vapour pressure:

0 Pa

at the temperature of:

20 °C