Tris(2-hydroxyethyl)ammonium chloride

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09. Apr. 2018 to 10. Apr. 2018

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:

-3.697

Temp.:

20 °C

pH:

>= 5.49 - <= 5.72

Analytical Determinations in Saturated Octanol

The measured values, the corresponding concentrations in saturated octanol and the amount in saturated octanol in the respective flasks are presented in the following table.

 

Step	Peak area [counts*min]	Concentration [µg/L]	Mean Concentration [mg/L]	Volume [mL]	Amount test item [mg]
1a	19248.8	137.3	0.138	10	0.00138
	19467.7	138.9
1b	18601.1	132.4	0.134	10	0.00134
	19047.4	135.8
2a	17940.5	127.4	0.126	5	0.00063
	17612.3	124.9
2b	17665.5	125.3	0.125	5	0.00062
	17502.0	124.1
3a	18889.5	134.6	0.134	20	0.00269
	18842.8	134.2
3b	18621.1	132.5	0.133	20	0.00266
	18733.5	133.4

 

Analytical Determinations inSaturatedWater

The measured values, the corresponding concentrations in the aqueous phase (calculated from calibration function and dilution factor 800), the resulting amount in the respective flasks and pH value in the aqueous phase are presented in Table below.

 

Step	Peak area [counts*min]	Concentration [µg/L]	Mean Concentration [mg/L]	Volume [mL]	Amount test item [mg]	pH value
1a	104052.2	680977.8	679.2	10	13.584	5.49
	103520.4	677447.7
1b	105025.3	687437.3	682.5	10	13.650	5.39
	103533.6	677535.7
2a	96913.9	633594.9	631.4	10	12.628	5.54
	96250.9	629194.1
2b	100994.1	660678.4	666.8	10	13.337	5.58
	102847.5	672981.3
3a	93829.2	613119.3	616.7	10	12.334	5.65
	94912.8	620312.0
3b	100455.6	657104.1	658.0	10	13.161	5.72
	100734.1	658952.9

 

Overview of determinations

The Pow for each determination, the mean, standard deviation and relative standard deviation of the six de-terminations are presented in the following table.

 

Step	Pow	Mean Pow of Step	Mean Pow	Standard Deviation	Relative Standard Deviation
1a	0.000203	0.000200	0.000201	0.00001	5.0 %
1b	0.000196
2a	0.000200	0.000193
2b	0.000187
3a	0.000218	0.000210
3b	0.000202

 

The log Pow for each determination, the mean, standard deviation and relative standard deviation of the six determinations at the three volume ratios is presented in the following table.

Step	log Pow	Mean log Pow	Range	Standard Deviation	Relative Standard Deviation
1a	-3.692	-3.697	-3.728 to -3.662	0.022	0.6 %
1b	-3.707
2a	-3.699
2b	-3.728
3a	-3.662
3b	-3.695

 

The log Pow of the test itemTriethanolamine hydrochloride at 20 °C was calculated as (log Pow ± standard deviation): -3.697 ± 0.022

 

Conclusions:

The log Pow of the test item was determined to be -3.697 ± 0.022 at pH 5.49 - 5.72 and 20.0 °C.

Executive summary:

A study was conducted in accordance with OECD TG 107 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the shake flask method. The equilibrium concentration of the test item in both phases was determined by means of HPLC. After adding the different amounts of stock solution, pre-saturated double distilled water and pre-saturated 1-octanol, all vials were closed and shaken for 5 minutes at 150 rpm. After shaking, the centrifuge vials were centrifuged at 20 °C for 15 minutes at 3000 rpm. Approximately 1 mL of the n-octanol phase was transferred to a HPLC vial using a Pasteur pipette, without touching the aqueous phase. The pH values of all water phases were measured. The phases of the shake-flask-method were measured twice. The partition coefficient of the test item was determined at 20 °C (pH 5.49 – 5.72) to be logPow = -3.691± 0.022.

Description of key information

The log Pow of the test item was determined to be -3.697 ± 0.022 at pH 5.49 - 5.72 and 20.0 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

-3.697

at the temperature of:

20 °C

Additional information

A study was conducted in accordance with OECD TG 107 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the shake flask method. The equilibrium concentration of the test item in both phases was determined by means of HPLC. After adding the different amounts of stock solution, pre-saturated double distilled water and pre-saturated 1-octanol, all vials were closed and shaken for 5 minutes at 150 rpm. After shaking, the centrifuge vials were centrifuged at 20 °C for 15 minutes at 3000 rpm. Approximately 1 mL of the n-octanol phase was transferred to a HPLC vial using a Pasteur pipette, without touching the aqueous phase. The pH values of all water phases were measured. The phases of the shake-flask-method were measured twice. The partition coefficient of the test item was determined at 20 °C (pH 5.49 – 5.72) to be logPow = -3.691± 0.022 (reference 4.7 -1).