Reaction products of diazotized mixture of aniline, toluidines and xylidines coupled with mixture of aniline, toluidines and xylidines, subsequently diazotized then coupled with 2-naphthol

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

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))

Deviations:

yes

Remarks:

Some retention times of test item peaks are below the retention times of the reference items. An extrapolation is required to determine the lower limit for the test item's log Koc. Minor impact on the conclusion of the test is expected.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Test temperature:

40°C (temperature of the column)

Details on study design: HPLC method:

1-Test system
Material and configuration:
System: Ultimate U-3000 (Thermo Fisher Scientific)
Software: Hystar_3.2 build 44 and DataAnalysis_4.1 build 359
Columns: HYPERSIL CN-CPS 5μm (4.6 x 150 mm)
Sample injection: 5 μl
Oven temperature: Column = 40°C+/- 0.1°C
Mobil phase and program: Isocratic mode, Flow : 0.5mL/min, A : 45% Ultrapure water (18.2 megaohms/cm), B : 55% Methanol (HPLC-MS grade), pH about 6 (using special indicator strips)
Detector: UV (210-800nm), Chromatogram analysis at 210 nm.

2- Solutions
See the details below

Key result

Sample No.:

#1

Type:

log Koc

Value:

>= 0.44 - <= 5.13 dimensionless

pH:

6

Temp.:

40 °C

Key result

Sample No.:

#2

Type:

log Koc

Value:

>= 0.44 - <= 5.13 dimensionless

pH:

6

Temp.:

40 °C

Details on results (HPLC method):

See the details below

Calibration and deadtime determination:

Reference item	Quantity introduce on the column (ng)	Retention times (min)	Log k’	Log Koc
Sodium nitrate (not retained by the column)	2.5	To = 1.89	N/A	(dead time determination)
Acetanilide	5	4.30	0.11	1.25
Atrazine	5	4.57	0.15	1.81
Linuron	5	5.14	0.24	2.59
Fenthion	5	5.81	0.32	3.31
Trifluralin	25	6.81	0.42	3.94
4,4’-DDT	50	7.82	0.50	5.63

Results:

Test item	Quantity introduce on the column (ng)	Retention times	Log k’		Log Koc
Solvent red 24 Mix	260	3.91 to 7.68	0.03 to 0.49		0.44* to 5.13
Solvent red 24 Mix	260	3.91 to 7.68	0.03 to 0.49		0.44* to 5.13
Mean				0.44 to 5.13

 * Log Koc calculated using extrapolation of regression line (Deviation n°1)

Validity criteria fulfilled:

yes

Conclusions:

The estimated Adsorption Coefficient (Koc) logarithm of the test item on Soil is in the range from 0.44 to 5.13.
Koc is therefore comprised between 1.55 and 169.02.

Key value for chemical safety assessment

Koc at 20 °C:

1.55