Denatonium benzoate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Experimental test result performed using standard OECD test guidelines

Justification for type of information:

Dats is from study report.

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))

GLP compliance:

not specified

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

- Name of test material (as cited in study report): N-benzyl-2-[(2,6-dimethylphenyl)amino]-N,N-diethyl-2-oxoethanaminium benzoate hydrate
- Molecular formula: C21H29N2O.C7H5O2
- Molecular weight: 446.58 g/mol
- Smilies notation: CC[N+](CC)(Cc1ccccc1)CC(=O)Nc2c(cccc2C)C.c1ccc(cc1)C(=O)[O-]
- InChl: 1S/C21H28N2O.C7H6O2/c1-5-23(6-2,15-19-13-8-7-9-14-19)16-20(24)22-21-17(3)11-10-12-18(21)4;8-7(9)6-4-2-1-3-5-6/h7-14H,5-6,15-16H2,1-4H3;1-5H,(H,8,9)
- Substance type: organic
- Physical state: White granular solid

Radiolabelling:

not specified

Details on study design: HPLC method:

The solutions of the test substance and reference substances were prepared in the mobile phase. Each of the reference substance and test substance were analysed by HPLC at 210 nm.
After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed.
Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(Annex - 2).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.

Chromatographic Conditions:
• HPLC Model No.: Agilent Technologies,1260 Infinity
• Flow Rate: 1.0ml/min
• Column: ZORBAX Eclipse Plus C18, 4.6×250mm, 5 µm
• Mobile phase: Methanol: water (55:45)
• Temperature : 25°C
• Detector: Diode Array Detector @210nm
• Injector: Autosampler
• Injector volume: 20µl
• Data Acquisition software: ChemStationOpen lab Control Panel
• Analysis time: 30min

Key result

Type:

log Koc

Value:

3.392

Temp.:

25 °C

Remarks on result:

other: 3.392± 0.007

Reference substance	Log Koc	tR1	tR2	tR3	MeantR± S.D.	k	Log k
Urea	-	2.367	2.368	2.365	2.366±0.001	-	-
Benzamide	1.239	3.326	3.322	-	3.324±0.002	0.4049	-0.392
N-methylbenzamide	1.3	3.603	3.608	-	3.6055±0.003	0.5238	-0.28
4-Nitrobenzamide	1.43	3.744	3.751	-	3.7475±0.004	0.5838	-0.233
N,N-dimethylbenzamide	1.52	4.294	4.296	-	4.295±0.001	0.8153	-0.088
4-methylaniline(p-Tolouidine)	1.9	5.192	5.2	-	5.196±0.001	1.196	0.077
4-chloroaniline	1.96	6.072	6.068	-	6.07±0.005	1.5655	0.194
N-methylaniline	2.28	6.548	6.559	-	6.5535±0.002	1.7698	0.247
Nitrobenzene	2.35	7.703	7.697	-	7.7±0.004	2.254	0.352
2 - nitrophenol	2.47	7.558	7.551	-	7.5545±0.004	2.192	0.34
phenanthrene	4.09	128.943	128.869	-	128.906±0.052	53.482	1.728

Test substance Denatonium benzoate (powder)		K	Log k	Log Koc by Generalized Calibration Graph	Mean of LogKoc± S.D.
tR1	2.201	-0.069	1.161	3.397	3.392± 0.007
tR2	2.20	-0.070	1.154	3.387

Conclusions:

The partition coefficient of test substance Denatonium benzoate (powder) (CAS No.3734-33-6) was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 3.392± 0.007 at 25°C

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge of Denatonium benzoate (powder) (CAS No. 3734-33-6)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated K_ocrange of the test substance and generalized calibration graph was prepared. The reference substances were 4 chloroaniline, 4 methylaniline, N methylaniline, 2 Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having K_ocvalue ranging from 1.239 to 4.09. The Log K_ocvalue was determined tobe 3.392± 0.007at 25°C. On the basis of log Koc value it is concluded that test chemical Denatonium benzoate has strong sorption to soil and sediment and therefore has negligible migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge of Denatonium benzoate (powder) (CAS No. 3734-33-6)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated K_ocrange of the test substance and generalized calibration graph was prepared. The reference substances were 4 chloroaniline, 4 methylaniline, N methylaniline, 2 Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having K_ocvalue ranging from 1.239 to 4.09. The Log K_ocvalue was determined tobe 3.392± 0.007at 25°C. On the basis of log Koc value it is concluded that test chemical Denatonium benzoate has strong sorption to soil and sediment and therefore has negligible migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

2 466.04

Additional information

Different experimental data studies have been conducted for adsorption endpoint for test chemical Denatonium benzoate in different forms i.e., granular form and powder form and results of all the studies are summarized below.

First experimental study was done by UERL laboratory (2015) in this study the adsorption coefficient Koc in soil and in sewage sludge of Denatonium benzoate (powder) (CAS No. 3734-33-6)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Kocrange of the test substance and generalized calibration graph was prepared. The reference substances used were 4 chloroaniline, 4 methylaniline, N methylaniline, 2 Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having Koc value ranging from 1.239 to 4.09. The Log Kocvalue was determined to be 3.392± 0.007at 25°C. On the basis of log Koc value it is concluded that test chemical Denatonium benzoate has strong sorption to soil and sediment and therefore has negligible migration potential to ground water.

Another experimental study was also conducted by UERL lab (2015) in this study the adsorption coefficient Koc in soil and in sewage sludge of Denatonium benzoate (Granules) (CAS No. 3734-33-6) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 4 chloroaniline, 4 methylaniline, N methylaniline, 2 Nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, Benzamide, phenanthrene having Kocvalue ranging from 1.239 to 4.09. The Log Koc value was determined to be 3.551± 0.071at 25°C. On the basis of log Koc value it is concluded that test chemical Denatonium benzoate has strong sorption to soil and sediment and therefore has negligible migration potential to ground water.

Last study was experimental study ( from European Draft Assessment Report, 2008) in this report the leaching behaviour of denatonium benzoate was assessed using the column leaching method in four different soil types. In three of the soils less than 0.05% of Denatonium benzoate (BITREX) appeared in the leachate. This indicates a strong adsorption of BITREX to those soils. However in the Boghall soil about 10% AR appeared in the leachate.It should be noted that due to the high amount of organic matter present in theBoghallsoil and its repellent properties to water the soil column was incompletely watering.In conclusion, denatonium benzoate has a high affinity to soil and has negligible potential for leaching.

On the basis of results of all above mentioned studies it is concluded that the test chemical Denatonium benzoate (CAS 3734 -33 -6) has a strong sorption to soil and sediment and therefore has negligible migration potential to groundwater.

[LogKoc: 3.392]