Reaction mass of Ammonium bisethanedioato bisaquo niobate(V) (anhydrous form) and Ammonium hydrogen ethanedioate ethanedioic acid (anhydrous form)

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 Apr - 25 Jun 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP - guideline study

Principles of method if other than guideline:

The partition coefficient was estimated based on the individual ratio between the n-octanol soluble parts of the test item and the water soluble parts of the test item. To provide at least laboratory based results for the n-octanol soluble parts of the test item the soluble parts of a defined amount of the test item were determined as niobium by ICP-MS.

GLP compliance:

yes (incl. QA statement)

Remarks:

LUBW Landesanstalt für Umwelt, Messungen und Naturschutz Baden-Württemberg, Karlsruhe, Germany

Type of method:

other: calculated from solubililty in water and n-octanol

Partition coefficient type:

octanol-water

Analytical method:

other: ICP-MS

Type:

Pow

Partition coefficient:

0

Temp.:

20 °C

pH:

0.43

Remarks on result:

other: The pH represents that of the water phase

Type:

log Pow

Partition coefficient:

-5.12

Temp.:

20 °C

pH:

0.43

Remarks on result:

other: The pH represents that of the water phase

Water solubility was determined at 20 °C and pH=0.43, the pH for the determination for solubility in n-octanol was not reported.

Time course of the measured soluble parts of Ammonium Niobium Oxalate at 20 °C in n-octanol:

Time / days	Sample	Weight sample in 300 mL n‑Octanol / g	Determined conc. of niobium / µg/L	Determined conc. of Ammonium Niobium Oxalate / µg/L	Mean determined conc. of Ammonium Niobium Oxalate ± RSD µg/L ± %	Mean soluble parts of Ammonium Niobium Oxalate in n‑octanol / µg/L
3	1	0.6460	306	1779	1602 ± 13.2
			223	1297
	2	0.6555	292	1698
			281	1634
10	1	0.6460	476	2767	2426 ± 13.5	2490
			453	2634
	2	0.6555	383	2227
			357	2076
12	1	0.6460	503	2924	2554 ± 18.2
			514	2988
	2	0.6555	373	2169
			367	2134

P_OW= c_n-octanol/c_water

With c_n-octanol= soluble parts of Ammonium Niobium Oxalate in n-octanol / µg/L and c_water= soluble parts of test item in water / µg/L (325 g/L at 20 °C and pH=0.43)

P_OW= estimated partition coefficient

P_OW=7.662*10^-6

The estimated log P_OW is approximately -5.12.

Description of key information

log Pow =-5.12 at 20 °C 

Key value for chemical safety assessment

Log Kow (Log Pow):

-5.12

at the temperature of:

20 °C

Additional information

The partition coefficient was estimated based on the individual ratio between the n-octanol soluble parts of the test item and the water soluble parts of the test item.