Butanamine, N,N-dibutyl-, branched and linear, fluorinated

Henry's Law constant

Administrative data

Endpoint:

Henry's law constant

Type of information:

experimental study

Adequacy of study:

key study

Study period:

8 Nov-15 Nov 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted in accordance with GLP standards and ETS-8-182, which is deemed appropriate for measurement of this endpoint.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

no guideline available

Deviations:

no

Principles of method if other than guideline:

Based on EPA method 8260A

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

FC-43

IUPAC Name:

FC-43

Details on test material:

- Name of test material (as cited in study report): FC-43 (perluorotributylamines), Perfluorotributylamines (PFTBA)
- Physical state: Colorless, clear liquid
- Analytical purity: 98.85%

Results and discussion

Henry's Law constant H

H:

> 166 000 dimensionless - volumetric basis

Temp.:

22 °C

Any other information on results incl. tables

Henry's Law constant (kH,cc) result is reported a dimensionless ratio of vapor phase concentration of FC-43 over aqueous phase concentration. From Table 10, the overall average kH,cc for the experiment was determined to be 166000. This quantity was used to express Henry's Law constants in conventional units which represent volatility. This can be done using the ideal gas law as follows:

kH,cc = Cg/Ca = kH,pc*RT

where kH,cc is the dimensionless Henry's Law constant, Cg is the concentration of the test substance in the gas phase, Ca is the concentration of test substance in the aqueous phase, kH,pc is the Henry's Law constant representing volatility, R is the ideal gas constant, and T is temperature in kelvin. Using the overall average dimensionless kH,cc for the experiment and average daily temperature of 22 °C (295 K), the Henry's Law constant can be expressed as 4020 atm m³/mol (4.07E+08 Pa m³/mol).

By including samples with different volumes of water and air and available glass surface, the study demonstrated that wall effects or slow mass transfer do not significantly affect the observed results:

kH,cc(FC-43)
		Day 1	Day 2	Day 3	Day 6
70% Headspace	Rep 1	>208000	>250000	83300^2	NR^1
	Rep 2	82600^2	>285000	69300^2	>309000
	Average	82600	>250000	76300	>309000
	%RPD	NA	NA	18	NA
50% Headspace	Rep 1	127000^3	237000^3	>246000	>364000
	Rep 2	>182000	217000^3	>257000	267000^3
	Average	127000	227000	>246000	267000
	%RPD	NA	8.8	NA	NA
30% Headspace	Rep 1	172000^2	223000^2	38100^2	>169000
	Rep 2	>185000	>264000	148000^2	324000^3
	Average	172000	223000	223000	324000
	%RPD	NA	NA	49	NA
Intra-Day Average		127000	226000	84700	296000
N measured values		3 of 12	3 of 12	4 of 12	2 of 12
%RSD		35	4.5	55	19
Overall Average		166000
%RSD		54

(1) Not reported due to data outliers.

(2) The concentration of both aliquots of the water phase were above the Limit of Quantitation. The average result was used to calculate log(kH,cc).

(3) The concentration of one of two aliquots of the water phase from this replicate was above the Limit of Quantitation. The higher result was used to calculate log(kH,cc) and therefore should be considered a minimum value.

Applicant's summary and conclusion

Conclusions:

The measured Henry's Law constant for FC-43 was determined to be greater than 4020 atm m³/mol at 22 °C

Executive summary:

The study reports a measured dimensionless Henry's Law constant of 166000 at an average daily temperature of 22 °C, which is expressed as the ratio of vapor phase concentration of FC-43 over aqueous phase concentration. As per Appendix R.7.1-4 Henry's law constant and evaporation rate, it is customary to find these constants reported as the ratio of vapor phase partial pressure over aqueous phase concentration in units of atm m³/mol. The Henry's Law constant expressed in conventional units is greater than 4020 atm m³/mol at 22 °C.

FC-43 kH,cc values were determined for individual replicates for each headspace ratio (approximately 30%, 50%, and 70%) at each time point (Day 1, Day 2, Day 3, and Day 6) to ensure that equilibrium conditions were obtained. The study was performed according to 3M Environmental Lab Protocol GLP11-0007, which is based on scientifically valid methods derived from published methods. Samples were analyzed using purge and trap GC/MS according to 3M Environmental Lab Method ETS-8-182 "Analysis of Volatile organic Compounds using Purge and Trap and Gas Chromatography/Mass Spectrometry". Henry's Law constant was also separately measured at three time points for two substances (TFE and OFCB) that have values reported in literature to document that the analytical techniques developed are suitable for this analysis. The kH,cc for TFE and OFCB determined in this study agreed within 15% of the literature reported values demonstrating suitability of the method applied to the test substance. No OECD guideline exists for measuring Henry's Law constants. The study was conducted in accordance with GLP standards and ETS-8-182, which is deemed appropriate for measurement of this endpoint. Therefore this study is classified as reliable without restrictions.