Reaction mass of 2,2'-(vinylenedi-p-phenylene)bis[5-methylbenzoxazole] and 2,2'-(vinylenedi-p- phenylene)bisbenzoxazole and 2-[4-[2-[4-(benzoxazol-2- yl)phenyl]vinyl]phenyl]-5-methylbenzoxazole

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:

March from 23 to 24, 2018

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:

adopted 22nd January 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Test temperature:

25 °C

Details on study design: HPLC method:

HPLC CONDITIONS
- Detector: 200 nm (for the reference items); 373 nm (for the test item)
- Column: LiChrospher 100 CN (5 µm) 250 × 4
- Temperature: 25 °C
- Mobile Phase: Acetonitrile : Water = 45 : 55 (v/v)
- Flow Rate: 1 ml/min
- Injection Volume: 10 µl

REFERENCE SUBSTANCES
Sodium nitrate, Acetanilide, Isoproturon, Naphthalene, 1,2,3-Trichlorobenzene, Fenthion, Pyrazophos and DDT.

TEST SOLUTIONS
The reference items were dissolved in Acetonitrile. The concentrations of the stock solutions were about 1 mg/ml. These stock solutions were diluted with eluent resulting in concentrations of approximately 10 µg/ml.
The test item was dissolved in Tetrahydrofuran. The concentration of the stock solution was about 0.2 mg/ml. This stock solution was diluted with eluent resulting in concentration of approximately 20 µg/ml

PERFORMANCE OF THE TEST
Three series of the reference solutions were measured with two parallel injections, each. Three series of the test item solution were measured with two parallel injections, each. The retention times were determined. The three calibration series and three test item series were measured alternately.
For the determination of t0 (t0 = retention time of the unretarded component) three series of sodium nitrate solution were injected twice.

Type:

log Koc

Value:

> 5.63

Temp.:

25 °C

Details on results (HPLC method):

Retention times measured for the three components of the test item (14.09, 15.82 and 17.84 min) are higher than the retention time of the last eluting standard: DDT (12.84 min). This result shows that log Koc of test item is higher than the calibrated range. As DDT is the reference item with the highest Koc value (OECD 121), no further test was performed.

Repeatability (difference of maximum and minimum values of log Koc): the value of log Koc derived from individual measurements fell within a range of 0.25 log units.
Reproducibility: the correlation coefficient R for the relationship between log k and log Koc for a set of the reference items was higher than 0.96.
Accuracy is the difference of the estimated adsorption coefficient to the literature value of reference item. It was within a range of ± 0.5 log units.

TEST ITEM

Test Item	Retention time (min)	log k Calculated	RepeatabilityΔlog Koc log unit	Accuracy log unit	log Koc Calculated
Test item (Constituent 1)	14.09	not calculated
	14.09
	14.09
	14.08
	14.1
	14.11
Mean	14.09
CV %	0.07
Test item (Constituent 2)	15.82	not calculated
	15.81
	15.81
	15.8
	15.84
	15.84
Mean	15.82
CV %	0.11
Test item (Constituent 3)	17.83	not calculated
	17.87
	17.76
	17.85
	17.81
	17.91
Mean	17.84
CV %	0.29

REFERENCE SUBSTANCES

Chemical name	log Koc OECD 121	Retention time (min)	log k Calculated	Repeatability Δlog Koc log unit	Accuracy log unit	log Koc Calculated
Sodium nitrate	-	1.13	-
		1.13
		1.11
		1.11
		1.1
		1.1
	Mean	1.11
	CV %	1.23
Acetanilide	1.25	3.38	0.309	0	0.27	0.98
		3.38	0.309			0.98
		3.38	0.309			0.98
		3.38	0.309			0.98
		3.38	0.309			0.98
		3.38	0.309			0.98
	Mean	3.38	0.309			0.98
	CV %	0	-			-
Isoproturon	1.86	4.38	0.467	0	0.14	2
		4.38	0.467			2
		4.38	0.467			2
		4.38	0.467			2
		4.38	0.467			2
		4.38	0.467			2
	Mean	4.38	0.467			2
	CV%	0	-			-
Naphthalene	2.75	5.62	0.607	0.01	0.13	2.89
		5.62	0.607			2.89
		5.61	0.606			2.88
		5.61	0.606			2.88
		5.61	0.606			2.88
		5.61	0.606			2.88
	Mean	5.61	0.607			2.88
	CV %	0.09	-			-
1,2,3-Trichlorobenzene	3.16	5.94	0.637	0.01	0.08	3.08
		5.95	0.638			3.08
		5.94	0.637			3.08
		5.94	0.637			3.08
		5.94	0.637			3.08
		5.94	0.637			3.08
	Mean	5.94	0.637			3.08
	CV %	0.07	-			-
Fenthion	3.31	7.13	0.733	0.01	0.37	3.69
		7.13	0.733			3.69
		7.11	0.731			3.68
		7.11	0.731			3.68
		7.11	0.731			3.68
		7.11	0.731			3.68
	Mean	7.12	0.732			3.68
	CV %	0.15	-			-
Pyrazophos	3.65	6.64	0.696	0.01	0.2	3.45
		6.63	0.695			3.45
		6.62	0.694			3.44
		6.62	0.694			3.44
		6.62	0.694			3.44
		6.62	0.694			3.44
	Mean	6.63	0.695			3.45
	CV %	0.13	-			-
DDT	5.63	12.85	1.023	0.01	0.09	5.54
		12.85	1.023			5.54
		12.82	1.022			5.53
		12.82	1.022			5.53
		12.84	1.023			5.54
		12.84	1.023			5.54
	Mean	12.84	1.022			5.54
	CV %	0.11	-			-

Conclusions:

log Koc > 5.63

Executive summary:

The estimation of the adsorption coefficient, Koc, has been done using the HPLC method, according to OECD guideline 121.

Three series of the reference solutions were measured with two parallel injections, each. Three series of the test item solution were measured with two parallel injections, each. The retention times were determined. The three calibration series and three test item series were measured alternately.

For the determination of t0 (t0 = retention time of the unretarded component) three series of sodium nitrate solution were injected twice.

The adsorption coefficient Koc was determined based on a calibration curve using 7 reference items. The capacity factors (k) were calculated from the dead time and retention times of the reference items. The log k data of the reference items were plotted against their log Koc values.

Retention times measured for the three components of the test item are higher than the retention time of the last eluting standard: DDT (12.84 min). This result shows that log Koc of test item is higher than the calibrated range. As DDT is the reference item with the highest Koc value (OECD 121), no further test was performed.

Conclusion

log Koc > 5.63

Description of key information

log Koc > 5.63

Additional information

The estimation of the adsorption coefficient, Koc, has been performed using the HPLC method, according to the OECD guideline 121. Three series of the reference solutions and test item were measured with two parallel injections, each. The three calibration series and three test item series were measured alternately. The adsorption coefficient Koc was determined based on a calibration curve using 7 reference items. The capacity factors (k) were calculated from the dead time and retention times of the reference items. The log k data of the reference items were plotted against their log Koc values.

Retention times measured for the three components of the test item are higher than the retention time of the last eluting standard: DDT (12.84 min). This result shows that log Koc of test item is higher than the calibrated range. As DDT is the reference item with the highest Koc value (OECD 121), no further test was performed.

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