Disodium hydrogen citrate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2017-07-12 to 2017-10-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

-1.624

Temp.:

20 °C

pH:

>= 2.23 - <= 2.25

Overview of determinations

The P_ow for each determination, the mean, standard deviation and relative standard deviation of the six determinations are presented in Table 1:

Table 1: P_ow

Step	Pow	Mean Pow Step	Mean Pow	Standard Deviation	Relative Standard Deviation
1a	0.03	0.0269	0.0242	0.0041	18.6
1b	0.03
2a	0.02	0.0216
2b	0.03
3a	0.02	0.0240
3b	0.03

The log P_ow for each determination, the mean, standard deviation and relative standard deviation of the six determinations at the three pHs is presented in Table 2:

Table 2: log P_ow

Step	log Pow	Mean log Pow	Range	Standard Deviation	Relative Standard Deviation
1a	-1.561	-1.624	-1.785 to -1.561	0.082	5.5%
1b	-1.580
2a	-1.785
2b	-1.572
3a	-1.679
3b	-1.567

Mass Balance

The mass balances of the individual determinations are presented in Table 3:

Table 3: Mass balance

Amount in n-Octanol	Amount in H2O	Total Amount	Nominal Amount	Difference	Recovery
mg	mg	mg	mg	mg	%
0.7	51.2	51.9	50.0	1.887	103.8
0.7	51.7	52.4	50.0	2.408	104.8
0.2	51.6	51.8	50.0	1.805	103.6
0.3	51.4	51.8	50.0	1.762	103.5
1.1	51.0	52.0	50.0	2.028	104.1
1.4	50.4	51.7	50.0	1.722	103.4

Conclusions:

Using shake flask method the log Pow of the test item was determined to be -1.624 ± 0.082. The result is also applicable for the water free form of the test item.

Executive summary:

A study was performed in order to determine the partition coefficient of the test item according to OECD TG 107 and Regulation (EC) No. 440/2008, method A.8 by using the shake flask method. The analytical determination was done by using HPLC. The log P_ow of the test item was determined to be -1.624 ± 0.082. The six log P_ow laid in a range of ± 0.3 units (0.224). The mass balances of the individual determinations showed 103.4 – 104.8 % deviation of nominal amount. Therefore the determination of the log P_ow was considered as valid. The results are also applicable for the water free form of the test item.

Description of key information

Using shake flask method the log P_ow of the test item was determined to be -1.624 ± 0.082 (pH between 2.23 and 2.25). The result is also applicable for the water free form of the test item.

Key value for chemical safety assessment

Log Kow (Log Pow):

-1.624

at the temperature of:

20 °C

Additional information

A study was performed in order to determine the partition coefficient of the test item according to OECD TG 107 and Regulation (EC) No. 440/2008, method A.8 by using the shake flask method (reference 4.7-1). The analytical determination was done by using HPLC. The log P_ow of the test item was determined to be -1.624 ± 0.082. The six log P_ow were in a range of ± 0.3 units (0.224). The mass balances of the individual determinations showed 103.4 – 104.8 % deviation of nominal amount. Therefore, the determination of the log P_ow was considered as valid. The results are also applicable for the water free form of the test item.