1,3-dimethyl-1,3-diphenylurea

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

14.3.2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable guideline study, tested with the source substance Ethyl centralite. According to the ECHA guidance “Practical guide 6" the reliability was changed to RL2 to reflect the fact that this study was conducted on a read-across substance.

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
1. HYPOTHESIS FOR THE ANALOGUE APPROACH
See attached document in IUCLID Section 13 - Read across.pdf

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See attached document in IUCLID Section 13 - Read across.pdf

3. ANALOGUE APPROACH JUSTIFICATION
[Summarise here based on available experimental data how these results verify that the read-across is justified]

!!! DOPLNIT podle Read across dokument

4. DATA MATRIX
See attached document in IUCLID Section 13 - Table 1: Data matrix

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across: supporting information

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))

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Test temperature:

25°C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Liquid chromatograph
- Type: Shimadzu LC-2012C(HT)
- Type, material and dimension of analytical (guard) column: Eclipse XDB-CN, 150x4.6 mm, 5µm
- Detection system: UV/VIS

MOBILE PHASES
- Type: MeOH with deionized water
- Experiments with additives carried out on separate columns: no
- pH: 6.2
- Solutes for dissolving test and reference substances: methanol

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

REFERENCE SUBSTANCES
- Identity: 2,5-Dichloroaniline 99.7%, Acetanilide ≥98%, Atrazine 98.8%, Linuron 99.9%, Monuron 99.9%, Phenyl benzoate ≥98%, Phenanthrene ≥97%,

DETERMINATION OF RETENTION TIMES
- Intervals of calibration: Soil - log Koc(x): 1.25 - 4.09, Sewage sludge - log Koc (x): 1.46 - 4.35

REPETITIONS
- Number of determinations: 4

- Injection volume: 10 µL

EVALUATION
The values of log k of individual repetitions are calculated from the individual retention times tR and the average value of t0. The mean of log k is calculated from the individual values of log k. The mean of log KOC of the sample as well as its uncertainty is calculated directly from the mean of log k of the sample and the calibration line.

Type:

log Koc

Remarks:

soil

Value:

2.3 - 2.86

Temp.:

25 °C

Type:

log Koc

Remarks:

sludge

Value:

1.88 - 3.12

Temp.:

25 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
2,5-Dichloroaniline - 3.214 min
Acetanilide - 2.193 min (used only for soils)
Atrazine - 2.564 min
Linuron - 3.906 min
Monuron - 2.668 min
Phenyl benzoate - 3.924 min
Phenanthrene - 6.323 min

- Details of fitted regression line (log k' vs. log Koc): see table 5 and table 8

- Average retention data for test substance: 3.405 min

Table 5: Estimations of parameters of linear regression curve

 

Parameter	Estimation	Standard deviation	Lower side of confidence interval		Upper side of confidence interval
Intercept (b)	-0.4470	0.0539	-0.5856		-0.3084
Slope (a)	0.2645	0.0208	0.2110		0.3180
Equation of linear regression curve:
logk=a. logKoc+b			logk=0.2645. logKOC- 0.4470
Statistic parameters:
Correlation coefficient			R	= 0.9849
Coefficient of determination			R^2	= 0.9700
Residual dispersion				= 0.0022
Number of levels			n	= 7
Number of repetitions			m	= 4
Student’s t-distribution				= 2.571

Table 8:Estimations of parameters of linear regression curve

Parameter	Estimation	Standard deviation	Lower side of confidence interval		Upper side of confidence interval
Intercept (b)	-0.2499	0.0779	-0.4662		-0.0337
Slope (a)	0.1942	0.0280	0.1164		0.2720
Equation of linear regression curve:
logk=a. log KOC+b			logk=0.1942. logKOC– 0.2499
Statistic parameters:
Correlation coefficient			R	=0.9608
Coefficient of determination			R^2	=0.9231
Residual dispersion				= 0.0045
Number of levels			n	= 6
Number of repetitions			m	= 4
Student’s t-distribution				= 2.776

Validity criteria fulfilled:

yes

Conclusions:

The study gives the following values for the estimation of adsorption coefficient (KOC) on soil and sewage sludge for Centralit:
Estimation of the adsorption coefficient (KOC) on soil and sewage sludge at given pH of mobile phase and set temperature:

log Koc (soil) = 2.58 +/- 0.28 (pH = 6.2, 25°C)
log Koc (sludge) = 2.50 +/- 0.62 (pH = 6.2, 25°C)

Executive summary:

The adsorption coefficient of test substance, Centralit, on soil and on sewage sludge was estimated. The HPLC method with reference compounds was used.

The test was performed according to the Method C.19, Estimation of the adsorption coefficient (KOC) on soil and sewage sludge using high performance liquid chromatography (HPLC), Council Regulation (EC) No 440/2008, Published in O.J.L 142, 2008.

 

The study gives the following values for the estimation of adsorption coefficient (Koc) on soil and sewage sludge for Centralit:

Estimation of the adsorption coefficient (KOC) on soil and sewage sludge at given pH of mobile phase and set temperature:

 

Log Koc (soil) = 2.58 +/- 0.28 (pH = 6.2, 25°C)

log Koc (sludge) = 2.50 +/- 0.62 (pH = 6.2, 25°C)

Description of key information

The adsorption coefficient of the read-across test substance Ethyl centralite, on soil and on sewage sludge was estimated. The HPLC method with reference compounds was used. The test was performed according to the Method C.19, Estimation of the adsorption coefficient (KOC) on soil and sewage sludge using high performance liquid chromatography (HPLC), Council Regulation (EC) No 440/2008, Published in O.J.L 142, 2008.

The study gives the following values for the estimation of adsorption coefficient (KOC) on soil and sewage sludge for the read-across test substance Ethyl centralite.

Estimation of the adsorption coefficient (KOC) on soil and sewage sludge at given pH of mobile phase and set temperature:

log Koc (soil) = 2.58 ± 0.28 (pH = 6.2, 25°C)

log Koc (sludge) = 2.50 ± 0.62 (pH = 6.2, 25°C)