Nonanamide, N,N-dimethyl-

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:

2017-05-12

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))

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))

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

-Test Item Properties
Test item: N,N-Dimethylnonanamide
Trade name: Genagen PA
Batch number: 112-2016-11 D
CAS No.: 6225-08-7
Sum formula: C11H23NO
Molecular weight: 185.31 g/mol
Purity (certified): 98.3% (w/w) (100% minus by-products)
Water solubility: approx. 340 mg/L (20 °C)
Appearance: Yellow clear liquid
Expiry date: May 2018
Recommended storage: Cool and dry (+2-+8 °C)

The test item and the information concerning the test item were provided by the sponsor.

-Test Facility Actions

Receipt: 2016-08-12
Identification parameter: Name, batch number, state, color and turbidity
Retention sample: At least 1 g has been retained on 2016-08-18 and stored at 6 ± 2 °C.
Storage at test facility: 6 ± 2 °C, protected from light in the tightly closed original container

Test temperature:

The test temperature was measured by a data logger with an interval of 2 minutes.
The mean temperature of 23.9 °C was inside the range of 20 - 25 °C ± 1 °C during the course of the study

Details on study design: HPLC method:

-Test system: Analytical HPLC-column (based on silica matrix), coupled to DAD, packed with a cyanopropyl solid phase containing non-polar and polar moieties. 

-Reasons for the selection: The selection of the test system is based on the guidelines. HPLC coupled to DAD is a useful method for estimation of the adsorption coefficient KOC. The KOC indicates the binding capacity of the test item on soil or sewage sludge and allows comparing the adsorption behaviour of different chemicals. The test item and reference items were detected by DAD.

-HPLC system HPLC AGILENT 1100 consisting of:
Auto sampler G1329A
Auto sampler thermostat G1330B
Pump G1312A
Degasser G1322A
Column oven G1316A
Detector G1315B

-Software: Empower 2 (Build No: 2154), WATERS

-Column: YMC-Pack Cyano, S-5µm, 12 nm, 250 x 4.0 mm, YMC EUROPE GMBH

Mobile phase : Methanol and HPLC water in a ratio 50 : 50. This mobile phase allowed the determination of the adsorption coefficient (KOC) for the test item in a reasonable period with suitable chromatographic properties for the test and reference items. No buffer was used because the adsorption coefficient (KOC) of the test item is independent on the pH value for this test item.

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

-Reagents: HPLC water, for HPLC, batch 17B174005, VWR
Methanol, gradient grade, batch 17C134009, VWR
3-Nitrobenzamide, 98%, batch 53297LJV, ALDRICH
Endosulfan-diol, 99.9%, batch SZBD302XV, SIGMA-ALDRICH

-Column temperature: 20 - 25 ± 1 °C

-Flow rate: 1.0 mL/min

-Injection volume: 20 µL

-Temperature monitoring: Data logger using 2 minutes interval

-System suitability: The following capacity factors k’ were reached:
log k’ > 0 for log KOC = 3.02 (Endosulfan-diol) and
log k’ > -0.4 for log KOC = 1.95 (3-Nitrobenzamide)
by using methanol : HPLC water (55 : 45) as mobile phase.

Key result

Type:

log Koc

Value:

ca. 2.32 dimensionless

Temp.:

24 °C

Remarks on result:

other: for soil

Temperature

The test temperature was measured by a data logger with an interval of 2 minutes.

The mean temperature of 23.9 °C wasinside the range of 20 - 25 °C ± 1 °C during the course of the study.Details are given in the table below.

 

Temperature Range

	Temperature[°C]
Min.	23.7
Max.	24.1
Mean Value	23.9

Dead Time of the HPLC-System

The HPLC dead time (t₀) was determined by threefold injection of a solution of 5 mg/L NaNO₃. The results are provided in the table below.

Dead Time of the HPLC-System

Injection No.	t0 [min]
1	1.526
2	1.524
3	1.524
Mean ± SD	1.525±0.001

            SD = Standard deviation

 

Calibration Data

 

Retention time data of the reference items used for calibration of soil and sewage sludge are given in the tables below.

 

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

Reference item	logKOC,soil	logKOC,sewage sludge	1. Calibration			2. Calibration
			tR1 [min]	k'	logk'	tR2 [min]	k'	logk'
Acetanilide	1.26	1.52	3.655	1.40	0.145	3.655	1.40	0.145
Atrazin	1.81	1.66	4.591	2.01	0.303	4.592	2.01	0.304
Aniline	2.07	1.74	4.679	2.07	0.316	4.438	1.91	0.281
2,5-Dichloroaniline	2.55	2.45	6.547	3.29	0.518	6.527	3.28	0.516
Linuron	2.59	2.43	8.915	4.85	0.685	8.891	4.83	0.684
Phenyl benzoate	2.87	3.26	8.908	4.84	0.685	8.880	4.82	0.683
Fenthion	3.31	3.75	17.544	10.5	1.02	17.517	10.5	1.02

t_R1       = Retention time 1^st injection                          t_R2    = Retention time 2^nd injection
k’      = Capacity factor                                              K_OC  = Adsorption coefficient

The corresponding calibration data for the corresponding calibration lines are summarized inTable 7. The calibration data were obtained from the regression line of the graph log K_OC vs. logk’ .

 

Calibration Data of the Reference Items for Soil and Sewage Sludge

	Soil		Sewage Sludge
	1. Calibration	2. Calibration	1. Calibration	2. Calibration
slope	2.226	2.182	2.711	2.679
intercept	1.184	1.219	0.979	1.011
r^2	0.9287	0.9163	0.9075	0.9092
r	0.9637	0.9572	0.9526	0.9535

r : Correlation coefficient                                          r²: Coefficient of determination

 

Results of Test Item Analysis

The table below contains the retention time data and calculated log k´ values for N,N-Dimethylnonanamide.

Two individual logK_OC values for the test item were derived under consideration of the first and second calibration. Finally, a mean value was calculated from these individual logK_OC value for soil and for sewage sludge.

Retention Times, Capacity Factors (k’) and Adsorption Coefficient (logK_OC)of
N,N-Dimethylnonanamidefor Soiland Sewage Sludge

	N,N-Dimethylnonanamide
	tR [min]	k’	logk’	logKOC, soil		logKOC,sewage sludge
				1^stCalibration	2^ndCalibration	1^stCalibration	2^ndCalibration
	6.399	3.20	0.505	2.31 ± 0.08 2.11 to 2.50 (95% CI)	2.32 ± 0.08 2.11 to 2.53 (95% CI)	2.35 ± 0.11 2.07 to 2.62 (95% CI)	2.36 ± 0.11 2.09 to 2.63 (95% CI)
	6.391	3.19	0.504
	6.391	3.19	0.504
Mean	6.394	3.19	0.504	2.32		2.35

t_R= Retention time                        SD = Standard deviation                         CI = Confidence interval

 

Validity criteria fulfilled:

yes

Remarks:

Calculated values for log KOC of the test item did not differ by more than 0.25 between injections. The variation in temperature was between ± 1 °C during the course of measurements. A signal-to-noise ratio > 3 was provided for all substances.

Conclusions:

The adsorption coefficient log KOC of the test item N,N-Dimethylnonanamide was determined to be 2.32 for soil and 2.35 for sewage sludge.

Executive summary:

The adsorption coefficient (K_OC) for the test itemN,N-Dimethylnonanamide (batch number:112-2016-11D) 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 on 2017-05-12 at Noack Laboratorien GmbH, 31157 Sarstedt, Germany.

 

The test was performed temperature controlled (23.9 °C, mean value), with a mobile phase consisting of 50% methanol and 50% HPLC water. A 50 mg/L sample of the test item
N,N-Dimethylnonanamide was analyzed threefold via HPLC on a cyanopropyl (CN-) column with DAD‑detection.

 

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

Two individual log K_OC values for soil and for sewage sludge for the test item were derived under consideration of the first and second calibration. Finally a mean value for soil and for sewage sludge was calculated from these individual logK_OC values. The results are shown in the table below.

 

Log K_OC Values forN,N-Dimethylnonanamidein Soil and Sewage Sludge

 

Test Item	logKOC, soil		logKOC,sewage sludge
	1. Calibration	2. Calibration	1. Calibration	2. Calibration
	2.31 ± 0.08 2.11 to 2.50 (95% CI)	2.32 ± 0.08 2.11 to 2.53 (95% CI)	2.35 ± 0.11 2.07 to 2.62 (95% CI)	2.36 ± 0.11 2.09 to 2.63 (95% CI)
Mean	2.32		2.35

K_OC         : Adsorption coefficientaccording to the guidelines

CI           : Confidence Interval

 

 

The adsorption coefficient logKOCfor the test item N,N-Dimethylnonanamide was calculated to be 2.32 for soil and 2.35 for sewage sludge.

 

Description of key information

The adsorption coefficient log KOC of the test item N,N-Dimethylnonanamide was determined to be 2.32 for soil and 2.35 for sewage sludge.

Key value for chemical safety assessment

Koc at 20 °C:

2.32