2-methyldecan-1-al

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:

30 March 2018 to 20 April 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted in accordance with international guidelines and in accordance with GLP. All relevant validity criteria were met.

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

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:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Radiolabelling:

no

Test temperature:

20 - 25 +/- 1 °C

Details on study design: HPLC method:

EQUIPMENT
HPLC-DAD/MS System: HPLC AGILENT 1100
Column: YMC-Pack Cyano, S-5 µm / 12nm 250 x 4.0 mm, batch 13303, YMC EUROPE GMBH

MOBILE PHASES
Acetonitrile and ultrapure water in a ratio 50 : 50 with a pH value of 6.7.

DETERMINATION OF DEAD TIME
- Method: HPLC dead time t0 was determined by threefold injection of a solution of 5 mg/L sodium nitrate

REFERENCE SUBSTANCES
- Identity:
1. Acetanilide (CAS No. 103-84-4, Purity 100 %, Batch No. BCBT8811)
2. Atrazine (CAS No. 1912-24-9, Purity 99.1 %, Batch No. SZBD158XV)
3. Monuron (CAS No. 150-68-5, Purity 99.9 %, Batch No. BCBW5539)
4. Linuron (CAS No. 330-55-2, Purity 99.4 %, Batch No. BCBS8699V)
5. Phenyl benzoate (CAS No. 93-99-2, Purity > 99.9 %, Batch No. STBF6278V)
6. Fenthion (CAS No. 55-38-9, Purity 97.7 %, Batch No. 5773700)
7. Phenanthrene (CAS No. 85-01-8, Purity 99.1 %, Batch No. XA26153V)
8. 4,4'-DDT (CAS No. 50-29-3, Purity 99.3 %, Batch No. BCBS5338V)

DETERMINATION OF RETENTION TIMES
- Test Item:
Stock solution: 2000 mg/L in acetonitrile
Test concentration: 500 mg/L
Dilution: With acetonitrile and ultrapure water to mobile phase ratio
Detection : With DAD range 190 nm – 400 nm
Wavelength: 290 nm
- Reference Items: Sodium nitrate was used for determination of the dead time of the test system. Eight reference items were used for soil and seven reference items were used for sewage sludge.
Stock solutions: 100 mg/L in ultrapure water for sodium nitrate, 100 mg/L for Endosulfan-diol and 3-Nitrobenzamide in methanol, 100 mg/L for the others in Acetonitrile,
Test concentrations: 20 mg/L for Endosulfan-diol, 5 mg/L for the others
Dilution: With acetonitrile, methanol and ultrapure water to mobile phase ratio.
Detection: With DAD range 190 nm – 400 nm

REPETITIONS
- Number of determinations:
Test Item: Replicates Single (three injections)
Reference Items: Sodium nitrate (three injections), Reference items, single with one injection before and one after the test item

EVALUATION
- Calculation of capacity factors k': Calibration of the method was done by determination of the retention times tR of the reference items (minimum of six items). Each reference item was analysed separately once before and after the test item.
The retention time was described by the capacity factor k’ given by the expression: k' = tR-t0 / t0
where: k’: capacity factor, tR: retention time, t0: dead time
- Determination of the log Koc value: By linear regression of the log k´ of the reference items against the log KOC of the reference items the equation for the calibration graph was obtained. Two individual adsorption coefficients for the test item were calculated by experimentally determining its capacity factor k´ and inserting k´ into the following equation: log Koc = a x log k + b
where: a: slope of the calibration graph, b: y-intercept of calibration graph
A mean value was calculated from these individual log KOC values.

Key result

Type:

Koc

Value:

7 943 L/kg

Temp.:

22.9 °C

Matrix:

Soil

Key result

Type:

log Koc

Value:

10 000 L/kg

Temp.:

22.9 °C

Matrix:

Sewage Sludge

Details on results (HPLC method):

Refer to data tables

Table 1. Dead Time of the HPLC System

Sample No.	Determination t0 (min)
1	1.357
2	1.357
3	1.356
Mean ± SD	1.357 ± 0.001

Table 2. Capacity Factors (k’) of the Reference Items for Soil and Sewage Sludge

			1st Calibration			2nd Calibration
Reference Item	Log Koc (soil)	Log Koc (sewage sludge)	tR1 (min)	k'	log k'	tR2 (min)	k'	log k'
Acetanilide	1.26	1.52	3.248	1.39	0.144	3.244	1.39	0.143
Atrazine	1.81	1.66	4.015	1.96	0.292	4.004	1.95	0.290
Monuron	1.99	1.46	3.820	1.82	0.259	3.816	1.81	0.258
Linuron	2.59	2.43	5.319	2.92	0.465	5.318	2.92	0.465
Phenyl benzoate	2.87	3.26	6.338	3.67	0.565	6.335	3.67	0.565
Fenthion	3.31	3.75	7.957	4.87	0.687	7.958	4.87	0.687
Phenanthrene	4.09	4.35	7.812	4.76	0.677	7.815	4.76	0.678
4,4 -DDT	5.63	-	15.991	10.8	1.03	16.042	10.8	1.03

Table 3. Calibration Data of the Reference Items for Soil and Sewage Sludge

	Soil		Sewage Sludge
	1st Calibration	2nd Calibration	1st Calibration	2nd Calibration
Slope	4.781	4.771	5.230	5.231
Intercept	0.4823	0.4893	0.3249	0.3346
r2	0.9571	0.9572	0.9206	0.9214
r	0.9783	0.9784	0.9595	0.9599

Table 4.

Retention Times, Capacity Factors (k’) and Adsorption Coefficient (log KOC) of 2-Methyldecan-1-al for Soil and Sewage Sludge

				Log Koc (soil) ± SD (95 % CI)		Log Koc (sewage sludge) ± SD (95 % CI)
	tR (min)	k'	log k'	1st Calibration	2nd Calibration	1st Calibration	2nd Calibration
	8.246	5.08	0.706
	8.251	5.08	0.706	3.9 ± 0.1 (3.5 to 4.2)	3.9 ± 0.1 (3.5 to 4.2)	4.0 ± 0.2 (3.4 to 4.6)	4.0 ± 0.2 (3.4 to 4.6)
	8.253	5.08	0.706
Mean	8.250	5.08	0.706	3.9		4.0

Validity criteria fulfilled:

yes

Conclusions:

Based on the results of a valid study conducted in accordance with OECD 121 (HPLC method), the following adsorption coefficients were determined:
Log Koc (soil) = 3.9
Log Koc (sewage sludge) = 4.0

Executive summary:

The adsorption coefficient (Koc) for the test item 2-Methyldecan-1-al (batch number: 461/16) on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 on 2018-04-04 at Noack Laboratorien GmbH, 31157 Sarstedt, Germany.

The test was performed at one pH value since the test item is not ionisable in the relevant pH range 5.5 to 7.5 and temperature controlled (22.9°C, mean value). Acetonitrile : ultrapure water (50 : 50 v/v) was used as mobile phase. A 500 mg/L sample of the test item 2-Methyldecan-1-al was analyzed threefold via HPLC on a cyanopropyl (CN-) column with DAD detection.

Calibrations were performed using eight reference items for soil and seven for sewage sludge with known log KOC values (given by the guidelines). The reference items were measured twice, once before and once after the measurement (double injection of one replicate) of the test item and were detected by DAD. Sodium nitrate was used for determination of dead time of the test system. One log KOC value for soil and one log KOC value for sewage sludge was derived under consideration of the first and second calibration.

Based on the results of the study, the following adsorption coefficients were determined:

Log Koc (soil) = 3.9

Log Koc (sewage sludge) = 4.0

Description of key information

Adsorption Coefficient: Koc (soil) = 7943 L/kg, Koc (sewage sludge) = 10000 L/kg; OECD 121 (HPLC); Goller, 2018

Key value for chemical safety assessment

Koc at 20 °C:

7 943

Additional information

In a single key study, the adsorption coefficient (Koc) of the test item on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 on 2018-04-04 at Noack Laboratorien GmbH, 31157 Sarstedt, Germany.

The test was performed at one pH value since the test item is not ionisable in the relevant pH range 5.5 to 7.5 and temperature controlled (22.9°C, mean value). Acetonitrile : ultrapure water (50 : 50 v/v) was used as mobile phase. A 500 mg/L sample of the test item 2-Methyldecan-1-al was analyzed threefold via HPLC on a cyanopropyl (CN-) column with DAD detection.

Calibrations were performed using eight reference items for soil and seven for sewage sludge with known log KOC values (given by the guidelines). The reference items were measured twice, once before and once after the measurement (double injection of one replicate) of the test item and were detected by DAD. Sodium nitrate was used for determination of dead time of the test system. One log KOC value for soil and one log KOC value for sewage sludge was derived under consideration of the first and second calibration.

Based on the results of the study, the following adsorption coefficients were determined:

Log Koc (soil) = 3.9 (key value for chemical safety assessment)

Log Koc (sewage sludge) = 4.0

[LogKoc: 3.9]