1-ethoxy-2,3-difluorobenzene

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:

2002-05-08 to 2002-05-13

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

REAGENTS
Methanole, Chromasolv Riedel de Haen
Distilled water, Roth
Potassium phosphate monobasic, Fluka (KH2PO4)
Sodium hydroxide, Riedel de Haen
Hydrochloric acid, Merck
Buffer pH 6: 13.61g KH2PO4 dissolved in distilled water and filled up to a volume of 1000 mL. 100 ml of this solution and 30 mL sodium hydroxide solution (c = 1 mole/L) diluted with distilled water and filled up to a volume of 1000 mL with distilled water, the pH value was adjusted to 6.0.
Dead time marker: Uracil, Riedel de Haen
Calibration substances

INSTRUMENTS
- Chromatographic apparatus
- Analytical balance Sartorius R160 P
- Ultrasonic bath Branson 3200
- General laboratory glassware

EQUIPMENT
- Apparatus:
HPLC pump G1311A
Autosampler G1313A
Column oven G1316A
UVA/IS detector G1314A by Agilent
Type: stationary phase: LiChrospher 100 CN 5µm by Duratec (18804-02)
Type, material and dimension of analytical (guard) column: Reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties, dimensions: 125 mm x4.6 mm; column temperature: 25 °C

MOBILE PHASES
- Type: methanol / buffer (pH 6.0) 55:45 (v/v), isocratic elution
- Experiments with additives carried out on separate columns: no
- Flow rate: 1.0 mL/min
- Detection wavelength: 220 nm

DETERMINATION OF DEAD TIME

- Method: by inert substances which are not retained by the column. The dead time marker was injected in triplet as solutions in acetonitrile/distilled water (50:50) (v/v). The calibration substances were dissolved in acetonitrile and diluted 0.1 to 1 in the mobile phase and injected as single standards twice a time. The test substance was dissolved in methanol and diluted 0.1 to 1 in the mobile phase and injected twice a time

REFERENCE SUBSTANCES
- Identity: Benzamide, Acetanilide, Monuron, Aniline, 3,5-Dinitrobenzamide, Triadimenol, Linuron, Tertbutryn, Naphthalene, Trifluralin, Diclofop-methyl and Quintozen.

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 9.31 µg
- Quantity of reference substances:
Dead time marker: 2.72 µg
Calibration substances: 0.66-2.75 µg
Test item: 9.31 µg

REPETITIONS
- Number of determinations: 2

Key result

Sample No.:

#2

Type:

Koc

Value:

501.187 dimensionless

Temp.:

25 °C

Key result

Sample No.:

#1

Type:

log Koc

Value:

2.7 dimensionless

Temp.:

25 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
4 Measurement:
Benzamide: 1.95
Acetanilide: 2.17
Monuron: 2.55
Aniline: 2.19
3,5-Dinitrobenzamide: 2.55
Triadimenol: 2.99
Linuron: 3.54
Terbutryn: 2.99
Naphthalene: 3.91
Trifluralin: 8.75
Diclofop-methyl: 6.19
Quintozen: 6.73


5 Measurement:
Benzamide: 1.96
Acetanilide: 2.18
Monuron: 2.57
Aniline: 2.20
3,5-Dinitrobenzamide: 2.56
Triadimenol: 3.00
Linuron: 3.58
Terbutryn: 3.03
Naphthalene: 3.96
Trifluralin: 8.97
Diclofop-methyl: 6.36
Quintozen: 6.91
- Details of fitted regression line (Log k vs Log Koc)
4. Measurement: y = 2.2778x + 2.8473; R2 = 0.9154
5. Measurement: y = 2.2727x + 2.8213; R2 = 0.9167
- Graph of regression line attached: yes
- Average retention data for test substance: 3.18 min
- The adsorption coefficient of the test item was found to be: log Koc: 2.7

Table 1: Determination of the Dead Time to

Dead time marker	Retention time of substances “tr” in min
	Measurement	Measurement	Measurement	Mean
Uracil	1.70	1.69	1.69	1.69

Dead time to = 1.69 min

Table 2: Calibration Data - 4. Measurement (*from OECD guideline 121, adopted January 2001)

Calibration substance	Inj. Retention time  in min	K	log K	log Koc*
Benzamide	1.95	0.15	-0.82	1.00
Acetanilide	2.17	0.28	-0.55	1.25
Monuron	2.55	0.51	-0.30	2.21
Aniline	2.19	0.29	-0.54	2.07
3,5-Dinitrobenzamide	2.55	0.50	-0.30	2.31
Triadimenol	2.99	0.76	-0.12	2.40
Linuron	3.54	1.09	0.04	2.59
Terbutryn	2.99	0.76	-0.12	2.68
Naphthalene	3.91	1.31	0.12	2.75
Trifluralin	8.75	4.17	0.62	3.94
Diclofop-methyl	6.19	2.66	0.42	4.20
Quintozen	6.73	2.97	0.47	4.34

Regression: log Koc = a + bx logk

Parameters: a = 2.847; b = 2.278; r2 = 0.9154

Table 3: log Koc of the Test Substance - 4. Measurement

Test substance	Inj. Retention time in min	K	log K	log Koc
1-Ethoxy-2,3-difluorbenzol	3.16	0.86	-0.06	2.70

Table 4: Calibration Data - 5. Measurement (*from OECD guideline 121, adopted January 2001)

Calibration substance	Inj. Retention time in min	K	log K	log Koc *
Benzamide	1.96	0.16	-0.80	1.00
Acetanilide	2.18	0.29	-0.54	1.25
Monuron	2.57	0.52	-0.29	2.21
Aniline	2.20	0.30	-0.53	2.07
3,5-Dinitrobenzamide	2.56	0.51	-0.29	2.31
Triadimenol	3.01	0.78	-0.11	2.40
Linuron	3.58	1.11	0.05	2.59
Terbutryn	3.03	0.79	-0.10	2.68
Naphthalene	3.96	1.34	0.13	2.75
Trifluralin	8.97	4.30	0.63	3.94
Diclofop-methyl	6.36	2.75	0.44	4.20
Quintozen	6.91	3.08	0.49	4.34

Regression: log Koc = a + bx logk

Parameters: a = 2.821; b = 2.273; r2 = 0.9167

Table 5: log Koc of the Test Substance - 5. Measurement

Test substance	Inj. Retention time in min	K	log K	log Koc
1-Ethoxy-2,3-difluorbenzol	3.18	0.88	-0.06	2.69

Table 6: log Koc of the Test Item

	Log Koc
4. Measurement	2.70
5. Measurement	2.69
Mean	2.70
RSD %	< 0.01

 

 

 

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient of the test substance has been determined according to the "HPLC- method" described in guideline 67/548/EEC, annex C.19 and OECD 121 (2001). The adsorption coefficient was found to be: log Koc = 2.7.

Executive summary:

The HPLC method is based on the correlation between the retention of a substance on a reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and the adsorption coefficient Koc. The dead time is determined by using a "dead time marker". For calibration the retention times of a series of substances with known adsorption coefficients were measured and a calibration graph was established. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The adsorption coefficient was found to be: log Koc = 2.7.

Description of key information

The adsorption coefficient of the test substance has been determined according to the "HPLC- method" described in guideline 67/548/EEC, annex C.19 and OECD 121 (2001). The adsorption coefficient was found to be: Koc = 501.187.

Key value for chemical safety assessment

Koc at 20 °C:

501.187

Additional information

The HPLC method is based on the correlation between the retention of a substance on a reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and the adsorption coefficient Koc. The dead time is determined by using a "dead time marker". For calibration the retention times of a series of substances with known adsorption coefficients were measured and a calibration graph was established. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The adsorption coefficient was found to be: Koc = 501.187