Phosphoric acid, 2-ethylhexyl ester, ammonium salt

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16-June-2017 to 09-March-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted in accordance OECD 121 and EC method C.19. All relevant validity criteria were met.

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Version / remarks:

22nd January 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

2008

Deviations:

no

Principles of method if other than guideline:

- Principle of test: no other principles
- Short description of test conditions: no other principles
- Parameters analysed / observed: no other principles

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other: silica/cyanopropyl

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: confidential
- Expiration date of the lot/batch: 01 Jan 2019
- Purity test date: N/D

RADIOLABELLING INFORMATION (if applicable)
- Radiochemical purity: N/A
- Specific activity: N/A
- Locations of the label: N/A
- Expiration date of radiochemical substance: N/A

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: dry, dark, cool (2-8 °C)
- Stability under test conditions: sufficient for the test purpose
- Solubility and stability of the test substance in the solvent/vehicle: N/A
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium: N/A

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: N/A
- Preliminary purification step (if any): N/A
- Final dilution of a dissolved solid, stock liquid or gel: N/A
- Final preparation of a solid: N/A

FORM AS APPLIED IN THE TEST (if different from that of starting material)

OTHER SPECIFICS: N/A

Radiolabelling:

no

Test temperature:

Column temperature: 25 ± 1 °C
Evaporator temperature: 30 °C
Nebulizer temperature: 30 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent 1260 HPLC system
- Type: HPLC
- Type, material and dimension of analytical (guard) column: EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm, Macherey-Nagel. Column packed with cyanopropyl as the solid phase and on a silica matrix.
- Detection system: Evaporative Light Scattering Detector

MOBILE PHASES
- Type: 55 % eluent 1 (methanol), 45 % eluent 2 (ultra-pure grade water (pH 5.94))
- Experiments with additives carried out on separate columns: no
- pH: 5.94
- Solutes for dissolving test and reference substances: not required

DETERMINATION OF DEAD TIME
- Method: The dead time t0 was measured by using the unretained compound sodium nitrate. Sodium nitrate was included in the used reference mix

REFERENCE SUBSTANCES
- Identity: Phenol, Isoproturon, naphthalene, 1,2,3-trichlorobenzene, phenanthrene, 4.4'-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10.13 g/L
- Quantity of reference substances: Sodium nitrate: 71.68 mg/L; Phenol: 19.85 mg/L; Isoproturon: 61.20 mg/L; Naphthalene: 3.55 mg/L; 1,2,3-Trichlorobenzene: 44.16 mg/L; Phenanthrene: 35.00 mg/L and 4'4'-DDT: 246.96 mg/L
- Intervals of calibration: calibration was conducted over 2 runs, and reference substances were run twice before and after the experiments.

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k':
log Koc = 3.0: log k’ > 0.0
log Koc = 2.0: log k’ > -0.4
- Calculation of retention times: The corresponding logarithms of the capacity factors, log k’, were calculated from the retention times and the dead time.
- Determination of the log Koc value: A correlation graph of log k’ versus log KOC was plotted. Log Koc was then determined based on the retention time of the substance.

Analytical monitoring:

yes

Details on sampling:

- Concentrations: One concentration of the test item was run the column, 10.13 g/L.
- Sampling interval: The retention time of the test item was determined 4 times.
- Sample storage before analysis: not stored.

Details on matrix:

The matrix was a synthetic matrix uing silica and a cyanoprpyl solid phase containing lipophilic and polar moieties. the matrix is not a true environmental matrix, but is in line with OECD guideline 121.

Details on test conditions:

TEST CONDITIONS
- Buffer: N/A
- pH: 5.94
- Suspended solids concentration: N/A
- other:

TEST SYSTEM
- Type, size and further details on reaction vessel: N/A
- Water filtered (i.e. yes/no; type of size of filter used, if any): yes, ultra pure grade water was used in the column during analysis.
- Amount of soil/sediment/sludge and water per treatment (if simulation test): N/A
- Soil/sediment/sludge-water ratio (if simulation test): N/A
- Number of reaction vessels/concentration: N/A
- Measuring equipment: HPLC
- Test performed in closed vessels due to significant volatility of test substance: N/A
- Test performed in open system: N/A
- Method of preparation of test solution: A sample was prepared containing 10.13 g/L test item in diluent (methanol).
- Are the residues from the adsorption phase used for desorption:
- Other:

Key result

Sample No.:

#1

Type:

log Koc

Value:

<= 1.51 dimensionless

pH:

5.94

Temp.:

25 °C

Remarks on result:

not determinable

Remarks:

Measure is mean of two runs. As the test item did not eluate as a single peak, the start and the end of the peak were used to calculate the range of the log Koc. This is the mean of the start and end of the peak retention time measurements.

Sample No.:

#2

Type:

log Koc

Value:

<= 1.32 dimensionless

pH:

5.94

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Measure is mean of two runs. As the test item did not eluate as a single peak, the start and the end of the peak were used to calculate the range of the log Koc. This is the mean of the start of the peak.

Sample No.:

#3

Type:

log Koc

Value:

1.51 dimensionless

pH:

5.94

Temp.:

25 °C

Remarks on result:

other:

Remarks:

Measure is mean of two runs. As the test item did not eluate as a single peak, the start and the end of the peak were used to calculate the range of the log Koc. This is the mean of the end of the peak.

Details on results (HPLC method):

- Retention times of reference substances used for calibration: please refer to table 1-4.
- Details of fitted regression line (log k' vs. log Koc): please refere to table 5 and 6.
- Graph of regression line attached: no
- Average retention data for test substance: 1.02 to 2.96 minutes. Retention time represents the measurement of the start and the end of a broad peak for the test item as the test item did not eluate as a single peak.

Details on results (Batch equilibrium method):

Not relevant.

Statistics:

Please refer to table 7.

Table 1:   Values fordeterminationoflog K_OC, dead time and calibration graph obtained from 1^strun at pH 5.94 (peak start)

Name	Log KOC nominal	RT^#	Mean RT ± SD	log k’	Log KOCdetermined	Mean log KOC ± SD log KOC
		[min]	[min]
		1.069	1.031	tR < t0	< 1.32*	< 1.32*
test item	---	1.044	0.032	tR < t0	< 1.32*	not applicable	Test
		0.997		tR < t0	< 1.32*		item
		1.014		tR < t0	< 1.32*
		1.119	1.098
Sodium nitrate^(1)	---	1.120	0.028	---	---	---	Dead
		1.060					time
		1.094
		2.664	2.665	0.154	1.21	1.21
Phenol	1.32	2.665	0.001	0.154	1.21	0.00
		2.665		0.154	1.21
		2.667		0.155	1.21
		3.459	3.461	0.332	1.92	1.93
Isoproturon	1.86	3.460	0.002	0.333	1.93	0.01
		3.462		0.333	1.93
		3.462		0.333	1.93
		5.184	5.186	0.571	2.88	2.88
Naphthalene	2.75	5.185	0.002	0.571	2.88	0.00	Reference
		5.187		0.571	2.88		Items
		5.187		0.571	2.88
		5.884	5.886	0.639	3.16	3.16
1,2,3-Trichlorobenzene	3.16	5.885	0.001	0.639	3.16	0.00
		5.887		0.640	3.16
		5.887		0.640	3.16
		8.853	8.856	0.849	4.00	4.00
Phenanthrene	4.09	8.855	0.002	0.849	4.00	0.00
		8.857		0.849	4.00
		8.857		0.849	4.00
		20.851	20.865	1.255	5.63	5.64
4.4'-DDT	5.63	20.855	0.014	1.255	5.63	0.01
		20.880		1.256	5.64
		20.874		1.256	5.64

⁽¹⁾:usedfordetermination of the dead time; RT = retention time; SD = standard deviation

t_R< t₀: Retention time of the test item (t_R) below retention time of sodium nitrate (t₀)

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) and below the lowest used reference standard (log K_OCof the lowest reference standard phenol is 1.32)

^#:  corrected retention time by subtraction the time shift of 0.046 minutes

 

Table 2:   Values fordeterminationoflog K_OC, dead time and calibration graph obtained from 2^nd run at pH 5.94 (peak start)

Name	Log KOC nominal	RT^#	Mean RT ± SD	log k’	Log KOCdetermined	Mean log KOC ± SD log KOC
		[min]	[min]
		1.071	1.004	tR< t0	< 1.32*	< 1.32*
Test item	---	0.994	0.061	tR< t0	< 1.32*	not applicable	Test
		0.926		tR< t0	< 1.32*		item
		1.026		tR< t0	< 1.32*
		1.121	1.099
Sodium nitrate^(1)	---	1.124	0.029	---	---	---	Dead
		1.063					time
		1.088
		2.666	2.667	0.154	1.21	1.21
Phenol	1.32	2.667	0.001	0.154	1.21	0.00
		2.668		0.155	1.21
		2.667		0.154	1.21
		3.459	3.461	0.332	1.92	1.92
Isoproturon	1.86	3.462	0.001	0.332	1.92	0.00
		3.461		0.332	1.92
		3.462		0.332	1.92
		5.186	5.188	0.570	2.88	2.88
Naphthalene	2.75	5.189	0.001	0.571	2.88	0.00	Reference
		5.188		0.571	2.88		Items
		5.188		0.571	2.88
		5.886	5.888	0.639	3.16	3.16
1,2,3-Trichlorobenzene	3.16	5.891	0.002	0.640	3.16	0.00
		5.888		0.639	3.16
		5.888		0.639	3.16
		8.853	8.857	0.849	4.00	4.00
Phenanthrene	4.09	8.861	0.003	0.849	4.00	0.00
		8.856		0.849	4.00
		8.858		0.849	4.00
		20.878	20.887	1.255	5.63	5.63
4.4'-DDT	5.63	20.891	0.006	1.255	5.63	0.00
		20.885		1.255	5.63
		20.892		1.256	5.64

⁽¹⁾:usedfordetermination of the dead time; RT = retention time; SD = standard deviation

t_R< t₀: Retention time of the test item (t_R) below retention time of sodium nitrate (t₀)

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) and below the lowest used reference standard (log K_OCof the lowest reference standard phenol is 1.32)

^#:  corrected retention time by subtraction the time shift of 0.046 minutes

 

 Table 3:   Values fordeterminationoflog K_OC, dead time and calibration graph obtained from 1^strun at pH 5.94 (peak end)

Name	Log KOC nominal	RT^#	Mean RT ± SD	log k’	Log KOCdetermined	Mean log KOC ± SD log KOC
		[min]	[min]
		3.092	2.906	0.259	1.63	< 1.5 (1.45)*
test item	---	2.931	0.140	0.223	< 1.5 (1.48)*	0.13	Test
		2.823		0.196	< 1.5 (1.37)*		item
		2.777		0.184	< 1.5 (1.33)*
		1.119	1.098
Sodium nitrate^(1)	---	1.120	0.028	---	---	---	Dead
		1.060					time
		1.094
		2.664	2.665	0.154	1.21	1.21
Phenol	1.32	2.665	0.001	0.154	1.21	0.00
		2.665		0.154	1.21
		2.667		0.155	1.21
		3.459	3.461	0.332	1.92	1.93
Isoproturon	1.86	3.460	0.002	0.333	1.93	0.01
		3.462		0.333	1.93
		3.462		0.333	1.93
		5.184	5.186	0.571	2.88	2.88
Naphthalene	2.75	5.185	0.002	0.571	2.88	0.00	Reference
		5.187		0.571	2.88		Items
		5.187		0.571	2.88
		5.884	5.886	0.639	3.16	3.16
1,2,3-Trichlorobenzene	3.16	5.885	0.001	0.639	3.16	0.00
		5.887		0.640	3.16
		5.887		0.640	3.16
		8.853	8.856	0.849	4.00	4.00
Phenanthrene	4.09	8.855	0.002	0.849	4.00	0.00
		8.857		0.849	4.00
		8.857		0.849	4.00
		20.851	20.865	1.255	5.63	5.64
4.4'-DDT	5.63	20.855	0.014	1.255	5.63	0.01
		20.880		1.256	5.64
		20.874		1.256	5.64

⁽¹⁾:usedfordetermination of the dead time; RT = retention time; SD = standard deviation

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log K_OCof the lowest reference standard phenol is 1.32)

^#:  corrected retention time by subtraction the time shift of 0.046 minutes

Table 4:   Values fordeterminationoflog K_OC, dead time and calibration graph obtained from 2^nd run at pH 5.94 (peak end)

Name	Log KOC nominal	RT^#	Mean RT ± SD	log k’	Log KOCdetermined	Mean log KOC ± SD log KOC
		[min]	[min]
		3.159	3.016	0.273	1.69	1.56
test item	---	3.041	0.110	0.247	1.58	0.10	Test
		2.954		0.227	1.50		item
		2.910		0.217	< 1.5 (1.46)*
		1.121	1.099
Sodium nitrate^(1)	---	1.124	0.029	---	---	---	Dead
		1.063					time
		1.088
		2.666	2.667	0.154	1.21	1.21
Phenol	1.32	2.667	0.001	0.154	1.21	0.00
		2.668		0.155	1.21
		2.667		0.154	1.21
		3.459	3.461	0.332	1.92	1.92
Isoproturon	1.86	3.462	0.001	0.332	1.92	0.00
		3.461		0.332	1.92
		3.462		0.332	1.92
		5.186	5.188	0.570	2.88	2.88
Naphthalene	2.75	5.189	0.001	0.571	2.88	0.00	Reference
		5.188		0.571	2.88		Items
		5.188		0.571	2.88
		5.886	5.888	0.639	3.16	3.16
1,2,3-Trichlorobenzene	3.16	5.891	0.002	0.640	3.16	0.00
		5.888		0.639	3.16
		5.888		0.639	3.16
		8.853	8.857	0.849	4.00	4.00
Phenanthrene	4.09	8.861	0.003	0.849	4.00	0.00
		8.856		0.849	4.00
		8.858		0.849	4.00
		20.878	20.887	1.255	5.63	5.63
4.4'-DDT	5.63	20.891	0.006	1.255	5.63	0.00
		20.885		1.255	5.63
		20.892		1.256	5.64

⁽¹⁾:usedfordetermination of the dead time; RT = retention time; SD = standard deviation

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log K_OCof the lowest reference standard phenol is 1.32

^#:  corrected retention time by subtraction the time shift of 0.046 minutes

Table 5:   Calibration parameter obtained from first run at pH 5.94

	Slope		Intercept
Log k‘ =	0.248670	× log KOC	- 0.145913
R =	0.9983

Table 6:   Calibration parameter obtained from second run at pH 5.94

	Slope		Intercept
Log k‘ =	0.248704	× log KOC	- 0.146271
R =	0.9983

Table 7:   Retention time and log K_OCof test item (mean of two runs) at pH 5.94

	Mean retention time	Mean retention time of two runs	Absolute deviation	Mean log KOC	Mean log KOCof two runs	Absolute deviation of log KOC
	[min]	[min]	[min]
First run - Peak Start	1.031	1.02	0.03	< 1.32*	< 1.32*	not applicable
Second run - Peak Start	1.004			< 1.32*
First run - Peak End	2.906	2.96	0.11	< 1.5 (1.45)^#	1.51	0.11
Second run - Peak End	3.016			1.56

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) and below the lowest used reference standard (log K_OCof the lowest reference standard phenol is 1.32)

*: below determination limit of the method (log K_OC= 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log K_OCof the lowest reference standard phenol is 1.32)

Validity criteria fulfilled:

yes

Conclusions:

The log Koc of two measurements made under identical conditions and using the same set of reference items fall within a range of ± 0.25 log units. The requirements of OECD guideline 121 concerning the quality criteria are fulfilled.

The log Koc was determed to be <= 1.51.

The aim of this study was the determination of the adsorption coefficient of Reaction mass of Ammonium mono(2-ethylhexyl)phosphate, Ammonium bis(2-ethylhexyl)phosphate and 2-ethylhexyl diphosphate ammonium salts on soil and on sewage sludge (KOC) by high performance liquid chromatography (HPLC) method according to EC method C.19 (440/2008) and OECD guideline 121.
The analysis was performed on an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties. A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm, Macherey-Nagel).
A of 55 % methanol / 45 % ultra-pure grade water (pH 5.94) was used as mobile phase and the column temperature was 25 °C ± 1 °C.
The results are listed below:
Mean retention time of two runs#
[min]
Absolute deviation
[min]
Mean log KOC of two runs#
Absolute deviation of log KOC
1.02 – 2.96*
≤ 0.11
≤ 1.51
≤ 0.11
#: As the test item did not eluate as a single peak, the start and the end of the peak were used to calculate the range of the log KOC.
*: The retention time of the test item was detected using an Evaporative Light Scattering Detector (ELSD). Therefore the detected retention time was corrected by the time shift of 0.046 min between PDA detector (used for reference items) and ELS detector (used for test item).

The log Koc of two measurements made under identical conditions and using the same set of reference items fall within a range of ± 0.25 log units. The requirements of OECD guideline 121 concerning the quality criteria are fulfilled.

Executive summary:

The aim of this study was the determination of the adsorption coefficient of Reaction mass of Ammonium mono(2-ethylhexyl)phosphate, Ammonium bis(2-ethylhexyl)phosphate and 2-ethylhexyl diphosphate ammonium salts on soil and on sewage sludge (K_OC) by high performance liquid chromatography (HPLC) method according to EC method C.19 (440/2008) and OECD guideline 121.

The analysis was performed on an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties. A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm, Macherey-Nagel).

A of 55 % methanol / 45 % ultra-pure grade water (pH 5.94) was used as mobile phase and the column temperature was 25 °C ± 1 °C.

The results are listed below:

Mean retention time of two runs^# [min]	Absolute deviation [min]	Mean log KOCof two runs^#	Absolute deviation of log KOC
1.02 – 2.96*	≤ 0.11	≤ 1.51	≤ 0.11

^#:  As the test item did not eluate as a single peak, the start and the end of the peak were used to calculate the range of the log K_OC.

*: The retention time of the test item was detected using an Evaporative Light Scattering Detector (ELSD). Therefore the detected retention time was corrected by the time shift of 0.046 min between PDA detector (used for reference items) and ELS detector (used for test item).

The log K_OC of two measurements made under identical conditions and using the same set of reference items fall within a range of ± 0.25 log units. The requirements of OECD guideline 121 concerning the quality criteria are fulfilled.

The Log K_OC was determined to be <=1.51.

Description of key information

Log Koc = <=1.51, OECD 121 (2001); Baer, 2017.

Key value for chemical safety assessment

Koc at 20 °C:

32

Additional information

The adsorption coefficient of Reaction mass of Ammonium mono(2-ethylhexyl)phosphate, Ammonium bis(2-ethylhexyl)phosphate and 2-ethylhexyl diphosphate ammonium salts on soil and on sewage sludge (KOC) was determined by high performance liquid chromatography (HPLC) method according to EC method C.19 (440/2008) and OECD guideline 121.

The analysis was performed on an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties. A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm, Macherey-Nagel).

A mixture of 55 % methanol / 45 % ultra-pure grade water (pH 5.94) was used as mobile phase and the column temperature was 25 °C ± 1 °C.

The log Koc of two measurements made under identical conditions and using the same set of reference items fall within a range of ± 0.25 log units. The requirements of OECD guideline 121 concerning the quality criteria are fulfilled.

The Log Koc was determined to be <=1.51

[LogKoc: 1.51]