5-potassium hydrogen L-glutamate

Vapour pressure

Administrative data

Endpoint:

vapour pressure

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method A.4 (Vapour Pressure)

GLP compliance:

yes (incl. QA statement)

Type of method:

effusion method: Knudsen cell

Test material

Test material information

1

Reference substance name:

5-potassium hydrogen L-glutamate

EC Number:

243-094-0

EC Name:

5-potassium hydrogen L-glutamate

Cas Number:

19473-49-5

Molecular formula:

C5H9NO4.K

IUPAC Name:

potassium 5-oxido-5-oxo-L-norvaline

Test material form:

solid

Results and discussion

Vapour pressure

Vapour pressure 1

Key result

Test no.:

#1

Temp.:

ca. 20 °C

Vapour pressure:

0.002 Pa

Vapour pressure 2

Key result

Test no.:

#2

Temp.:

ca. 25 °C

Vapour pressure:

ca. 0.003 Pa

Any other information on results incl. tables

Vapour pressure ofL-Glutamic Acid Monopotassium Salt Monohydrateat 20 °C and 25 °C  was  calculated on the basis of equation: log (p) = f (1/t) = a-b/(t+273.15) where: p – vapour pressure in Pa,t – temperature in °C, obtained for four measurement points: 57.7°C, 62.7°C, 66.0°C and 69.6°C.

Applicant's summary and conclusion

Conclusions:

The determined vapour pressure of L-Glutamic Acid Monopotassium Salt Monohydrate:
at 20 0C 1.89·10-3 Pa
at 25 0C 3.41·10-3 Pa

Executive summary:

The determined vapour pressure is:

Test sample	Vapour pressure at 20^0C	Vapour pressure at 25^0C
L-Glutamic Acid Monopotassium Salt Monohydrate	1.89·10^-3Pa	3.41·10^-3Pa

 

 

The study of the vapour pressure determination using effusion methodwas performedin accordance with an elaborated Standard Operating Procedure SPO/BC/13/b (3^rded.). This procedure complies with the method EC A4 .

The described method is used for liquid and solid substances.Recommended by guideline range for this effusion method using Knudsen cell is 10^-10to 1Pa, however apparatus used in our laboratory makes it possible to determine vapour pressure in the range from 10^-15Pa to 500

The method is based on the estimation of the test substance mass flowing out the Knudsen cell per unit of time, through a micro-orifice under ultra-vacuum conditions.

The vapour pressure was calculated by applying the Hertz-Knudsen relation with Clausing correction factor f that depends on parameters of the apparatus:on the ratio of orifice length to orifice radius.

 

 

where:

G= evaporation rate (kg s^-1);

M= molar mass (g mol^-1);

T= temperature (K);

R= universal gas constant (J mol^-1K^-1);

p= vapour pressure (Pa);

f = Clausing factor;                                                       

A = area of Knudsen cell orifice (m²)

 

 

Vapour pressure ofL-Glutamic Acid Monopotassium Salt Monohydrateat 20 °C and 25 °C  was  calculated on the basis of equation: log (p) = f (1/t) = a-b/(t+273.15) where: p – vapour pressure in Pa,t – temperature in °C, obtained for four measurement points: 57.7°C, 62.7°C, 66.0°C and 69.6°C.