RD 14153

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 24 March 2016 and 08 April 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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:

22 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:

30 May 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: sponsor Lot/Batch number 5399661C10
- Expiration date of the lot/batch: 24 February 2020
- Purity test date:

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

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature in the dark
- Stability under test conditions:
- Solubility and stability of the test substance in the solvent/vehicle:
- Reactivity of the test substance with the solvent/vehicle of the cell culture medium:

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

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

OTHER SPECIFICS:

Radiolabelling:

no

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC
- Type: Agilent Technologies 1200 series
- Type, material and dimension of analytical (guard) column: Waters XSelect HSS Cyano 5 mm (150 x 4.6 mm id)
- Detection system: UV detector wavelength : 210 nm

MOBILE PHASES
- Type: Reverse phase: Methanol: purified water (55:45 v/v) Ramp to 100% Methanol post 30 minutes (over 30 mins) for samples only
- Experiments with additives carried out on separate columns: no
- pH: 6.9
- Solutes for dissolving test and reference substances: methanol

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column - formamide

REFERENCE SUBSTANCES
- Identity: Acetanilide, Phenol, Atrazine, Isoproturon, Triademinol, Linuron, Napthalene, Endosulfan-diol, Fenthion, alpha-Endpsulfan, Phenanthrene, Diclofop-methyl, DDT (Table 1 below)

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 26.25 µg
- Quantity of reference substances: 1 - 1.6 µg
- Intervals of calibration:

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': yes
- Calculation of retention times: no
- Determination of the log Koc value: yes

Key result

Sample No.:

#1

Type:

Koc

Value:

ca. 17.8 - < 427 000 dimensionless

pH:

7

Temp.:

30 °C

Matrix:

Cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties was used.

Remarks on result:

other: pH nominal 7 (not n=measured because

Remarks:

test substance has no ionisable groups

Details on results (HPLC method):

- Retention times of reference substances used for calibration: See Table 2
- Details of fitted regression line (log k' vs. log Koc): Y = 0.3368x - 0.7311
- Graph of regression line attached: no
- Average retention data for test substance: 21.65 mins

Table 2: Retention times, capacity factors and log₁₀ K_oc values for reference standards.

Standard	Mean retention time (mins)	Capacity factor (k')	Log10 k'	Log10 Koc
Acetanilide	2.711	0.365	-0.437	1.25
Phenol	2.566	0.292	-0.535	1.32
Atrazine	3.738	0.883	-5.42 x 10^-2	1.81
Isoproturon	3.984	1.01	2.64 x 10^-3	1.86
Triadimenol	5.320	1.68	0.225	2.40
Linuron	5.433	1.74	0.240	2.59
Naphthalene	4.696	1.37	0.135	2.75
Endosulfan-diol	6.650	2.35	0.371	3.02
Fenthion	8.057	3.06	0.485	3.31
alpha-Endosulfan	11.300	4.695	0.671	4.09
Phenanthrene	8.729	3.40	0.531	4.09
Diclofop-methyl	12.234	5.16	0.713	4.20
DDT	24.461	11.3	1.05	5.63

Table 3: Retention times, capacity factor, log₁₀ and K_oc values for RD14153

Peak	Mean retention time (mins)	Mean capacity factor (k')	Mean Log10 Koc	Adsorption coeff.	Mean % area
1	2.182	9.90 x 10^-2	<1.25	<17.8	28.8
2	21.137	9.65	5.09	1.24 x 10^5	60.3
3	43.480	20.9	>5.63	>4.27 x 10^5	6.43
4	47.797	23.1	>5.63	>4.27 x 10^5	1.55
5	49.770	24.1	>5.63	>4.27 x 10^5	0.40
6	50.501	24.4	>5.63	>4.27 x 10^5	1.48
7	53.352	25.9	>5.63	>4.27 x 10^5	1.08

Validity criteria fulfilled:

yes

Conclusions:

The test item has a range of adsorption coefficient results, with the main peak by area percent being present at an adsorption coefficient of 1.24 x 105 (log10 Koc 5.09).
The adsorption coefficient (Koc) of the test item has been determined to have a range of <17.8 to > 4.27 x 105, log10 Koc <1.25 to >5.63, with the largest peak by area percent being represented by an adsorption coefficient 1.24 x 105, log10 Koc 5.09.

Executive summary:

The adsorption coefficient of RD 14153 has been determined to be have a range of <17.8 to >4.27 x 10⁵. log₁₀ K_oc <1.25 to >5.63, with the largest peak by area being representes by an adsorption coefficient of 1.24 x 10⁵, log₁₀ K_oc 5.09. using the HPLC screening method.

Description of key information

The adsorption coefficient of RD 14153 has been determined to be have a range of <17.8 to >4.27 x 10⁵. log₁₀K_oc<1.25 to >5.63, with the largest peak by area being representes by an adsorption coefficient of 1.24 x 10⁵, log₁₀K_oc5.09. using the HPLC screening method.

Key value for chemical safety assessment

Koc at 20 °C:

123 027

Additional information

[LogKoc: 5.09]