Glycine hydrochloride

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019-03-29 to 2019-04-10

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), 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:

-3.25

Temp.:

20 °C

pH:

7

Details on results:

The study was performed using the flask method. As the test item is a zwitterionic amino acid, the partition coefficient was determined using n-octanol and phosphate buffer, pH 7. Three volume ratios of buffer : n-octanol (1 : 1, 1 : 2, 1 : 4) were tested in duplicate. Overall mean log Pow was -3.25 ± 0.08 with relative standard deviation 2.4 %

Analytical Determinations n-octanol

The measured values, the corresponding concentrations in n-octanol (calculated from calibration function and dilution factor) and the amount in n-octanol in the respective flasks are presented in the following table. 

Step	Peak area [mAU*min]	Concentration [mg/L]	Amount test item [µg]
1a	17.4387	0.47	7.090
	17.5185
1b	17.0377	0.47	6.976
	17.3573
2a	19.4317	0.52	3.911
	19.1407
2b	20.2051	0.53	4.006
	19.3045
3a	12.8845	0.34	6.894
	12.5922
3b	13.2365	0.35	7.090
	12.9678

 

Analytical Determinations buffer

The measured values, the corresponding concentrations in the aqueous phase (calculated from calibration function and dilution factor) and the amount in the respective flasks are presented in the following table.

Step	Peak area [mAU*min]	Dilution Factor	Concentration [mg/L]	Amount test item [mg]
1a	34.7133	1000	779.61	23.395
	35.5299
1b	39.1351	1000	876.05	26.288
	39.8042
2a	35.4336	1000	793.86	23.820
	36.0941
2b	35.0046	1000	779.18	23.479
	35.1995
3a	34.6313	1000	777.50	15.657
	35.4216
3b	34.2398	1000	756.06	15.128
	33.8799

 

Overview of Determinations

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 Step	Mean log Pow	Range	Standard Deviation	Relative Standard Deviation
1a	-3.22	-3.28	-3.25	0.19	0.08	2.4 %
1b	-3.28
2a	-3.18	-3.17
2b	-3.16
3a	-3.35	-3.34
3b	-3.33

 

Conclusions:

The overall mean log Pow was determined to be -3.25 ± 0.08 with relative standard deviation 2.4 % at 20 °C and pH=7.

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. As the test item is a zwitterionic amino acid, the partition coefficient was determined using n-octanol and phosphate buffer, pH 7. Three volume ratios of buffer : n-octanol (1 : 1, 1 : 2, 1 : 4) were tested in duplicate. The separated phases were analysed using HPLC-FLD method. For each flask, the log Pow was calculated and the mean, standard deviation and relative standard deviation of the six log Pow values were calculated. The overall log Pow of the test item was calculated to be -3.25 ± 0.08 at 20 °C and pH=7.

Description of key information

The overall mean log Pow was determined to be -3.25 ± 0.08 with relative standard deviation 2.4 % at 20 °C and pH=7.

Key value for chemical safety assessment

Log Kow (Log Pow):

-3.25

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 (reference 4.7-1). The equilibrium concentration of the test item in both phases was determined by means of HPLC. As the test item is a zwitterionic amino acid, the partition coefficient was determined using n-octanol and phosphate buffer, pH 7. Three volume ratios of buffer : n-octanol (1 : 1, 1 : 2, 1 : 4) were tested in duplicate. The separated phases were analysed using HPLC-FLD method. For each flask, the log Pow was calculated and the mean, standard deviation and relative standard deviation of the six log Pow values were calculated. The overall log Pow of the test item was calculated to be -3.25 ± 0.08 at 20 °C and pH 7.