Hexafluoropropene, oxidized, oligomers, reduced, fluorinated

Solubility in organic solvents / fat solubility

Link to relevant study record(s)

Reference

Endpoint:

solubility in organic solvents / fat solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 November 2013 to 31 January 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD Guideline-conform study conducted under GLP.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Testing Guideline No.105 (1995)_Water Solubility

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: CIPAC, Physico-chemical Methods for Technical and Formulated Pesticides

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: EU Method A.6 "water solubility" Council Regulation (EC) No 440/2008.

Deviations:

no

Principles of method if other than guideline:

No test guideline is currently available for the measurement of the solubility in n-Octanol, therefore the determination was based on the principles of OECD guideline No. 105 and EU Method A.6 “Water Solubility”.
 

GLP compliance:

yes (incl. QA statement)

Medium:

n-octanol

Solubility:

12.7 g/L

Temp.:

20 °C

Remarks on result:

other: Method A Analysis: 5 minutes 5000 r.p.m. Centrifugation + GC/FID determination

Medium:

n-octanol

Solubility:

24.2 g/L

Temp.:

20 °C

Remarks on result:

other: Method B Analysis: GC/FID determination

Test substance stable:

yes

Details on results:

The solubility in n-Octanol of the test item samples determined according to method A (including centrifugation) was 12.7 g/L at 20°C and 14.2 g/L at 20°C according to method B. The difference between the two values of solubility (defined with and without centrifugation) was ascribed to the presence of emulsions generated during the shaking phase which have been removed during the centrifugation step.
The higher variability in the analysis results of the three flasks analyzed without including the centrifugation phase is consistent with this hypothesis.

Table 1: n-Octanol solubility results _Method A : 5 minutes 5000 r.p.m. Centrifugation + GC/FID determination.

Flask / Replicate	Concentration (μg/mL)	Mean (g/L)
Flask A1	12656.1	12.67
Flask A2	12679.7
Flask B1	12592.3	12.65
Flask B2	12706.8
Flask C1	12798.5	12.80
Flask C2	12806.2
Mean value		12.7
Standard Deviation		0.08
Relative Standard Deviation (%)		0.66 %

Table 2: n-Octanol solubility results _Method B: GC/FID determination

Flask / Replicate	Concentration (μg/mL)	Mean (g/L)
Flask A1	14084.2	14.07
Flask A2	14062.9
Flask B1	13958.3	14.00
Flask B2	14044.9
Flask C1	14642.0	14.66
Flask C2	14677.0
Mean value		14.2
Standard Deviation		0.36
Relative Standard Deviation (%)		2.53 %

Conclusions:

The n-Octanol solubility of the test item was determined to be 12.7 g/L.

Executive summary:

The solubility in n-Octanol of the test item was determined under GLP according to OECD standard guidelines. Since no test guideline is currently available for the measurement of the solubility in n-Octanol the determination was based on the principles of OECD guideline No. 105 and EU Method A.6 “Water Solubility”.

 

A preliminary GLP test according to CIPAC method MT 157 was performed with the purpose of defining the range of solubility. The n-Octanol solubility of the test item resulted in the range 10 to 50 g/L therefore a definitive test according to shake flask method, including the analytical determination, was performed.

 

Three samples (about 2.5 g each) of test item were weighed into three 100 mL conical flasks, 100 mL of n-Octanol were added and each flask was closed with a polypropylene stopper in order to have the minimum head space.

Three flasks, labelled "A" "B" and "C" were shaken in a thermostatic oven with magnetic stirrer for 24 (Flask A), 48 (Flask B), and 72 (Flask C) hours, respectively. Then the flasks were allowed to stand at 20°C in a thermostatic oven for 24 hours. The solutions were collected and the concentration of test item was analytically determined by GC coupled with FID detector. Calculations were made by an external standard.

Since the test item is known for the tendency in forming emulsions when shaken, prior of the analytical determination every solution (A, B and C ) was treated according to two different methods, in order to verify the presence of emulsions:

Method A

An aliquot of each solution (A , B and C ) was centrifugated at 5000 r.p.m. for 5 minutes and then 5 mL of supernatant were transferred into 20.00 mL volumetric flask making to volume with n-Octanol. The resulting solutions were analyzed by GC/FID.

 

Method B

5 mL aliquots of each solution (A , B and C ) were transferred into 20.00 mL volumetric flask making to volume with n-Octanol. The resulting solutions were analyzed by GC/FID.

 

The solubility in n-Octanol of the test item samples determined according to method A (including centrifugation) was 12.7 g/L at 20°C while the solubility according to method B was 14.2 g/L at 20°C. The difference between the two values of solubility (defined with and without centrifugation) was ascribed to the presence of emulsions generated during the shaking phase which have been removed during the centrifugation step.

The higher variability in the analysis results of the three flasks analyzed without including the centrifugation phase is consistent with this hypothesis.

Basing on this the value of 12.7 g/L is considered more representative of the solubility of the test item in n-Octanol.

Description of key information

The solubility in n-Octanol of GALDEN LMW was experimetally determined to be 12.7 g/L.

Additional information

The solubility in n-Octanol of the test item was determined under GLP according to OECD standard guidelines. Since no test guideline is currently available for the measurement of the solubility in n-Octanol the determination was based on the principles of OECD guideline No. 105 and EU Method A.6 “Water Solubility”.

According to the results, it can be concluded that the solubility of GALDEN LMW in n-Octanol is 12.7 g/L at 20°C.

Galden is a multi-constituent substance consisting of low molecular weight perfluoropolyethers (PFPE). Perfluorinated substances typically have a low affinity for water. Two grades of Galden LMW are manufactured (Galden HT55 and Galden HT70), which contain the same perfluorinated constituents and differ only in the relative concentration of the constituents.

As the two grades both contain only perfluorinated constituents (albeit in different relative concentrations), the solubility of both Galden grades is very similar. The value of 12.7 g/L therefore is representative for both grades.