Hexanamide, N-(2-ethylhexyl)-3,5,5-trimethyl-

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:

2012-11-02 to 2012-11-03

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:

and Directive 2001/59/EC Method C.19

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

other: soil and sewage sludge

Radiolabelling:

no

Test temperature:

The column temperature during the study was monitored every 2 minutes by a data logger. A mean value of 22.9 °C was obtained for the temperature during the course of the study.

Temperature Range

Temperature [°C]
Min. 22.8
Max. 23.1
Mean Value 22.9

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
HPLC AGILENT 1100 consisting of:
Auto sampler : G1329A
Auto sampler thermostat: G1330B
Degasser: G1322A
Column oven: G1316A
Detector (test system): G1315B
Pump: G1312A
Software: Empower 2 (Build No: 2154), Waters

CONDITIONS OF ANALYSIS
HPLC-column: YMC-Pack CN, 250 x 4.0 mm, S-5 µm, 12 nm, Gel. lot 11334,
YMC EUROPE GMBH
Column temperature 20-25 °C

Additional Equipment Analytical balance, SARTORIUS
Data logger/thermometer TESTO 175-T3
Direct displacement pipettes, GILSON
Laboratory glassware
Piston stroke pipettes, THERMO SCIENTIFIC
Top pan balance, KERN


Mobile phase Acetonitrile : HPLC water (55 : 45)


REFERENCE SUBSTANCES
- Identity: Reference Substances for Adsorption Coefficient in Soil and Sewage Sludge:

Reference item CAS-No. log KOC, soil log KOC, sewage sludge
Acetanilide 103-84-4 1.26 1.52
Monuron 150-68-5 1.99 1.46
Atrazine 1912-24-9 1.81 1.66
Linuron 330-55-2 2.59 2.43
Benzoic acid 93-99-2 2.87 3.26
phenylester
Fenthion 55-38-9 3.31 3.75
Phenanthrene 85-01-8 4.09 4.35
DDT 50-29-3 5.63 -



DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: Approx. 55 mg/L
- Quantity of reference substances: Approx. 5 mg/L
- Intervals of calibration: Set of reference substance - one before and one after the test item


REPETITIONS
- Number of determinations:
Test item: Single replicate (three injections)
Reference item:
Two injections (one before and one after the analysis of the test item)
Three injections for NaNO3 at the beginning of the sample set.



EVALUATION
- Calculation of capacity factors k': k = (tR-t0)/t0
- Determination of the log Koc value:
By linear regression of the log KOC of the reference items against the log k’ of the reference items the equation for the calibration graph was obtained.
Two individual adsorption coefficient log KOC for the test item were calculated by experimentally determining its capacity factor k’ and inserting k’ into the equations obtained from the first and second calibration graph:
logKoc = a*logk'+b
a: slope of the calibration graph, b: y-intercept of calibration graph
Finally, a mean value was calculated from these individual log KOC values for soil and for sewage sludge, respectively.

Analytical monitoring:

not required

Type:

log Koc

Value:

3.8 dimensionless

Matrix:

Soil

Type:

log Koc

Value:

4 dimensionless

Matrix:

Sewage sludge

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
Capacity Factors (k’) of the Reference Items for Soil and Sewage Sludge

Reference item log KOC, log KOC 1st Calibration 2nd Calibration
soil sewage sludge tR1 [min] k' log k' tR2 [min] k' log k'
Acetanilide 1.26 1.52 2.881 1.340 0.127 2.877 1.337 0.126
Monuron 1.99 1.46 3.267 1.654 0.219 3.261 1.649 0.217
Atrazine 1.81 1.66 3.439 1.794 0.254 3.433 1.789 0.253
Linuron 2.59 2.43 4.345 2.530 0.403 4.339 2.525 0.402
Benzoic acid 2.87 3.26 4.978 3.044 0.483 4.970 3.037 0.482
phenylester
Fenthion 3.31 3.75 5.960 3.842 0.585 5.951 3.834 0.584
Phenanthrene 4.09 4.35 5.997 3.872 0.588 5.988 3.864 0.587
4,4’-DDT 5.63 - 10.674 7.333 0.865 10.675 7.333 0.865

tR1 = Retention time 1. Injection; tR2 = Retention time 2. Injection
k’ = Capacity factor; KOC = Adsorption coefficient

The corresponding calibration data for the corresponding calibration lines are summarized in the table below. The calibration data were obtained from the regression line of the graph log KOC vs. log k’.

Calibration Data of the Reference Items for Soil and Sewage Sludge
Soil Sewage Sludge
1st Calibration 2nd Calibration 1st Calibration 2nd Calibration
slope 5.691 5.682 6.127 6.123
intercept 0.4368 0.4465 0.3055 0.3140
r2 0.9563 0.9563 0.9268 0.9271
r 0.9779 0.9779 0.9627 0.9629
r : Correlation Coefficient; r2 : Coefficient of determination


- Average retention data for test substance:
Soil:
Two individual log KOC values for the test item were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual log KOC values for soil.
An individual log KOC value of 3.8 ± 0.1 (95 % CI 3.5 to 4.2) was obtained with both calibrations. The individual values did not differ more than ± 0.25 log KOC values. Based on these data a mean value of 3.8 was derived.

Retention Times, Capacity Factors (k’) and Adsorption Coefficient (KOC) of Antimussol ZJ for soil

log KOC, soil 95 % CI
tR [min] k' log k' 1st Calibration 2nd Calibration

Antimussol ZJ
6.103 3.96 0.5975 3.8 ± 0.1 3.8 ± 0.1
6.102 3.96 0.5974 3.5 to 4.2 3.5 to 4.2
6.099 3.95 0.5971
Mean 6.101 3.96 0.5973 3.8

tR = Retetntion time
CI = Confidence Interval


Sewage:
Two individual log KOC values for the test item were derived under consideration of the first and second calibration. Finally a mean value was calculated from these individual log KOC values for sewage sludge.
An individual log KOC value of 4.0 ± 0.2 (95 % CI 3.4 to 4.5) was obtained with both calibrations. The individual values did not differ more than ± 0.25 log KOC values. Based on these data a mean value of 4.0 was derived.

Retention Times, Capacity Factors (k’) and Adsorption Coefficient (KOC) of Antimussol ZJ for Sewage Sludge

log KOC, soil 95 % CI
tR [min] k' log k' 1st Calibration 2nd Calibration

Antimussol ZJ
6.103 3.96 0.5975 4.0 ± 0.2 4.0 ± 0.2
6.102 3.96 0.5974 3.4 to 4.5 3.4 to 4.5
6.099 3.95 0.5971
Mean 6.101 3.96 0.5973 4.0

tR = Retetntion time
CI = Confidence Interval

Dead Time of the HPLC-System

Serial No.	t0 [min]	t0only for DDT [min]
1	1.230	1.280
2	1.231	1.282
3	1.232	-
Mean ± SD	1.231±0.001	1.281±0.001

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient log KOC of the test item Antimussol ZJ was determined to be 3.8 for soil and 4.0 for sewage sludge.

Executive summary:

The adsorption coefficient (K_OC) on soil and on sewage sludge using high performance liquid chromatography (HPLC) was estimated according to OECD/OCDE 121 (2001) and Council Regulation (EC) No. 440/2008, Method C.19 for the test itemAntimussol ZJ (batch number:ESD0015431)from 2013-11-21 to 2013-12-20 at Dr.U.Noack‑Laboratorien, 31157 Sarstedt, Germany.

 

The test was performed temperature controlled, (22.9 °C, mean value) with a mobile phase consisting of 55 % acetonitrile and 45 % HPLC water. A 55mg/L sample of the test item Antimussol ZJ was analyzed threefold via HPLC on a cyanopropyl (CN-) column with PDA‑detection.

 

Calibrations were performed using eight reference items for soil and seven for sewage sludgewith known logK_OCvalues (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. Dead time of the HPLC-system was determined with sodium nitrate.

 

Two individual logK_OCvalues for soil and for sewage sludge forthe test item were derived under consideration of the first and second calibration. Finally, a mean valuefor soil and for sewage sludgewas calculated from these individual logK_OCvalues. Based on these data a logK_OCof 3.8 for soil and a logK_OCof 4.0 for sewage sludge were determined for Antimussol ZJ.

Test Item AntimussolZJ	logKOC, soil		logKOC,sewage sludge
	1^stCalibration	2^ndCalibration	1^stCalibration	2^ndCalibration
	3.8 ± 0.1 3.5  to 4.2 (95 % CI)	3.8 ± 0.1 3.5 to 4.2 (95 % CI)	4.0 ± 0.2 3.4 to 4.5 (95 % CI)	4.0 ± 0.2 3.4 to 4.5 (95 % CI)
Mean	3.8		4.0

K_OC         : Adsorption coefficient

CI           : Confidence Interval

The adsorption coefficient logKOCforAntimussol ZJ was determined to be 3.8 for soil and 4.0 for sewage sludge.

Description of key information

The adsorption coefficient log KOC of the test item Antimussol ZJ was determined to be 3.8 for soil and 4.0 for sewage sludge.

Key value for chemical safety assessment

Koc at 20 °C:

6 309

Additional information

[LogKoc: 3.8]