ethyl 5,5-diphenyl-2-isoxazoline-3-carboxylate

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))

Version / remarks:

2001

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:

2001

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

40 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC
- Type: Kontron HPLC system with autosampler 465, gradient former 425, pump 422 and column oven 480
- Type, material and dimension of analytical column: Stainless steel (Bischoff) 250 x 4.6 mm, stationary phase: Zorbax CN, 5 µm, column temperature: 40°C
- Detection system: UV/VIS detector 430

MOBILE PHASES
- Type: Methanol / water (55:45) (v/v) (isocratic elution), 1.0 ml/min flow rate
- Experiments with additives carried out on separate columns: no
- Solutes for dissolving test and reference substances: Methanol

DETERMINATION OF DEAD TIME
- Method: by means of homologous series of n-alkyl methyl ketones

REFERENCE SUBSTANCES
- Identity: Acetanilide, atrazine, anilin, carbendazim, linuron, endosulfan-diol, fenthion, pyrazophos, alpha-endosulfan, and diclofop-methyl were used as calibration substances

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 20 µl
- Quantity of reference substances: 20 µl
- Intervals of calibration: 1 calibration with 2 injections before both experimental Log Koc determinations of the test item

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': k' = tr-t0/t0, with tr = retention time of substances and t0 = dead time
- Calculation of retention times: Retention times of selected reference compounds with known adsorption coefficients are measured to establish a calibration graph. In a further step the log Koc of the test item should be derived from its retention time.
- Determination of the log Koc value: log Koc = a + b x log k'

Sample No.:

#1

Type:

log Koc

Value:

3.4 dimensionless

Temp.:

40 °C

Sample No.:

#1

Type:

Koc

Value:

2 512 dimensionless

Temp.:

40 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration: "See any other information on results incl. tables"
- Details of fitted regression line (log k' vs. log Koc): R^2 of run 1 = 0.9110, r^2 of run 2 = 0.9582
- Average retention data for test substance: Mean tr run 1 = 12.755 min, mean tr run 2 = 12.615 min, overall mean = 12.685 min

Table 1: Calibration data of Run 1

Calibration substance	Mean tR(min)	K’	Log k’	Log Koc*
Acetanilide	4.035	0.5056	-0.2962	1.25
Atrazine	5.075	0.8937	-0.0488	1.81
Anilin	7.630	1.8470	0.2665	2.07
Carbendazim	8.685	2.2407	0.3504	2.35
Linuron	8.650	2.2276	0.3478	2.59
Endosulfan-diol	10.390	2.8769	0.4589	3.02
Fenthion	15.045	4.6138	0.6641	3.31
Pyrazophos	14.180	4.2910	0.6326	3.65
Alpha-Endosulfan	17.570	5.5560	0.7448	4.09
Diclofop-methyl	17.700	5.6045	0.7485	4.20

* from OECD guideline TG 121

Parameters of regression: a = 1.7772, b = 2.7317, r²= 0.9110

Table 2: Log K_OCof test item Run 1

Substance	Mean tR(min)	K’	Log k’	Log Koc*
Isoxadifen-ethyl	12.755	3.7593	0.5751	3.35

 

Table 3: Calibration data of Run 2

Calibration substance	Mean tR(min)	K’	Log k’	Log Koc*
Acetanilide	3.995	0.5070	-0.2950	1.25
Atrazine	5.015	0.8917	-0.0498	1.81
Anilin	5.805	1.1897	0.0755	2.07
Carbendazim	6.610	1.4934	0.1742	2.35
Linuron	8.550	2.2252	0.3474	2.59
Endosulfan-diol	10.325	2.8948	0.4616	3.02
Fenthion	14.865	4.6073	0.6634	3.31
Pyrazophos	13.955	4.2641	0.6298	3.65
Alpha-Endosulfan	17.260	5.5108	0.7412	4.09
Diclofop-methyl	17.375	5.5541	0.7446	4.20

* from OECD guideline TG 121

Parameters of regression: a = 1.8999, b = 2.6741, r²= 0.9582

Table 4: Log K_OCof test item Run 2

Substance	Mean tR(min)	K’	Log k’	Log Koc*
Isoxadifen-ethyl	12.615	3.7586	0.5750	3.44

Validity criteria fulfilled:

not specified

Description of key information

Log Koc (Isoxadifen-ethyl) = 3.4 (40 °C, OECD 121, 2001)

The parent substance has a low adsorption potential to soil and sediment.

Key value for chemical safety assessment

Koc at 20 °C:

2 512

Additional information

A study were performed according to OECD 121 study (GLP) with the target compound isoxadifen-ethyl.

The study resulted in a measured log Koc of 3.4 at 40 °C. Therefore, the target compounds is expected to show only a low adsorption onto soil and sediment.