Methanaminium, N,N,N-trimethyl-, 2,2-dimethylpropanoate (1:1)

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

June - December 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)

Deviations:

not specified

GLP compliance:

yes

Type of method:

batch equilibrium method

Media:

soil

Specific details on test material used for the study:

Lot: 13AP016
Purity: > 99%
Expiration date: 2018-05-01
Appearance: White Solid

Radiolabelling:

not specified

Test temperature:

25±0.5 °C

Details on study design: HPLC method:

HPLC-MS/MS conditions
Apparatus: LC-Agilent Technologies 1290 Infinity
Column: ZORBAX Eclipse Plus Cl8 Column ( 150 mmx 2. l mm, 3.5µm, Agilent, USA)
Mobile phase: acetonitrile: 0.02% ammonia = 70:30 ( v/v)
Flow rate: 0.3 mL/min
Column Temperature: 30°C
Injection volume: 5 µL
Under the above conditions, the retention time of test substance was about 0.97 min.
MS/MS condition:
Apparatus: MS-AB SCIEX QTRAP 4500
Ion source type: ESI, negative
TEM: 500°C

Analytical monitoring:

yes

Details on sampling:

Five soils were selected and used. The equilibration time (48 h), the soil/solution ratio (1 :1), the weight of the soil sample (50g), the volume of the aqueous phase in contact with the soil (50 mL) and the concentration of the test substance in the solution (0.50 mg/L) were chosen based on the preliminary study results. Analysis was performed approximately after 2h, 4h, 6h, 1Oh, 24h, 48 h contact times.

Details on matrix:

The soils were characterized by four parameters considered to be largely responsible for the adsorptive capacity: organic carbon, clay content, soil texture, and pH. The soils selected for this study is from Jilin (A black soil), Jiangxi (B red soil), Jiangsu (C paddy soil), Shandong (D brown soil) and Gansu (E meadow soil) and the properties of soil which were determined by Institute of soil science, Chinese academy of sciences.

Sample No.:

#1

Type:

Koc

Value:

6.18 dimensionless

Temp.:

25 °C

Matrix:

Soil1

Sample No.:

#2

Type:

Koc

Value:

9.47 dimensionless

Temp.:

25 °C

Sample No.:

#3

Type:

Koc

Value:

6.74 dimensionless

Temp.:

25 °C

Sample No.:

#4

Type:

Koc

Value:

18.7 dimensionless

Temp.:

25 °C

Sample No.:

#5

Type:

Koc

Value:

3.37 dimensionless

Temp.:

25 °C

Concentration of test substance at end of desorption equilibration period:

The results of desorption kinetic experiments show that in 48 h desorption equilibrium period, liquid concentrations of the test substance in five soil desorption experiments were lower than LOD for their low adsorption (LOD=3.00 µg/L).

Transformation products:

not specified

Details on results (Batch equilibrium method):

The results of mass balance show that at the test concentration of 0.50 mg/L, the recoveries of the test substance from the whole test procedure were 70.0%, 86.8%, 72.0%, 78.0% and 79.6% in soils A, B, C, D, E, respectively.

Validity criteria fulfilled:

not specified

Conclusions:

The results of adsorption kinetic experiments show that the adsorption coefficient (Kd) values of test substance in A, B, C, D, E soil are 0.404, 0.129, 0.361, 0.260 and 0.231 cm3 g-1, respectively.
The Koc values of test substance are 6.18, 9.49, 6.74, 18.7 and 3.37 cm3 g-1 in above soils respectively, and the average Koc values is 8.90 cm3 g-1

Executive summary:

In an OECD 106 "Adsorption Desorption Using a Batch Equilibrium Method" test, five type soils with different pH, texture, clay content and organic carbon contents sampling from Jilin (A black soil), Jiangxi (B red soil), Jiangsu (C paddy soil), Shandong (D brown soil) and Gansu (E meadow soil) provinces of China were selected. Batch equilibrium method was adopted, and preliminary test, adsorption/desorption kinetics test and adsorption/desorption isotherms test were performed to determine the adsorption characteristics of test substance in this study.

The results show that optimal soil/aqueous ratio for five soils are 1/1, respectively, and the appropriate adsorption equilibrium time is 48 h.

The results of adsorption kinetic experiments show that the adsorption coefficient (Kd) values of test substance in A, B, C, D, E soil are 0.404, 0.129, 0.361, 0.260 and 0.231 cm3 g-1, respectively.

The Koc values of test substance are 6.18, 9.49, 6.74, 18.7 and 3.37 cm3 g-1 in above soils respectively, and the average Koc values is 8.90 cm3 g-1.

The results of desorption kinetic experiments show that in 48 h desorption equilibrium period, liquid concentrations of the test substance in five soil desorption experiments were lower than LOD for their low adsorption (LOD=3.00 µg/L).

The results of mass balance show that at the test concentration of 0.50 mg/L, the recoveries of the test substance from the whole test procedure were 70.0%, 86.8%, 72.0%, 78.0% and 79.6% in soils A, B, C, D, E, respectively.

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

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:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Details on study design: HPLC method:

The determination was carried out using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.
The test system utilized a high performance liquid chromatograph. A commercially available cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties was used.
Preparation of dead time solution
The dead time was determined by measuring the retention time of formamide (purity* 99.6%) at 0.583 g/L in methanol.
Preparation of reference standard solutions
Solutions of reference standards (acetanilide, atrazine, triadimenol, naphtalene, fention, DDT, phenantrene) were prepared in methanol.
Preparation of sample solution
Test item (0.1011 g) was diluted to 100 mL with methanol to give a concentration of 1.01 g/L.
following HPLC parameters:
HPLC System :
Agilent Technologies 1100, incorporating workstation and autosampler
Detector :
diode array detector (DAD)
Column :
Waters XSelect HSS CN 5μm (150 x 4.6 mm id)
Column temperature :
30 °C
Mobile phase :
methanol:purified water (55:45 v/v)
pH of mobile phase :
6.3
Flow-rate :
1.0 mL/min
Injection volume :
5 μL
DAD wavelength :
210 nm

Sample No.:

#1

Type:

Koc

Value:

< 17.8 dimensionless

Temp.:

21 °C

Sample No.:

#2

Type:

Koc

Value:

< 17.8 dimensionless

Temp.:

21 °C

Details on results (HPLC method):

The test item was an organic salt with the cationic component being a quaternary ammonium compound. The test method is not applicable in determining the adsorption coefficient of quaternary ammonium compounds since adsorption is dominated by cationic exchange. The cationic exchange capacity of a soil significantly affects the adsorption of quaternary ammonium compounds. Methods C.19 and OECD 121 do not address cationic exchange potential of soils. Therefore no result for the cation was possible.
For additional confirmation, the sample and blank were analysed using mass spectrometry. This was done to confirm the presence of the anionic component of the test item using an m/z of 101. From the typical chromatography, it can be seen there is a peak in the sample only which coincides with the peak from the UV detection.
During trials using mass spectrometry, the cationic component was not detected with a column or without a column. It was considered that it may have adsorbed essentially irreversibly and any that eluted did so gradually and not as a detectable specific peak. This was not an issue as the test was not applicable, as mentioned above.

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient for the anionic component of Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid a.k.a. Tetramethylammonium Pivalate Salt., has been determined to be less than 17.8, log10 Koc of <1.25, using the HPLC screening method.

Executive summary:

The adsorption coefficient for the anionic component of Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid a.k.a. Tetramethylammonium Pivalate Salt., has been determined to be less than 17.8, log10 Koc of <1.25, using the HPLC screening method, designed to be compatible with Method C.19 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 121 of the OECD Guidelines for Testing of Chemicals, 22 January 2001.

As the cationic component of the test item was a quaternary ammonium compound, the test methods were not applicable since adsorption of cations is in part due to cationic exchange.

Description of key information

The adsorption coefficient for the anionic component of Methanaminium, N,N,N-trimethyl-, salt with 2,2-dimethylpropanoic acid a.k.a. Tetramethylammonium Pivalate Salt., has been determined to be less than 17.8, log10 Koc of <1.25, using the HPLC screening method.

In a supporting study, the results of adsorption kinetic experiments show that the adsorption coefficient (Kd) values of test substance in A, B, C, D, E soil are 0.404, 0.129, 0.361, 0.260 and 0.231 cm3 g-1, respectively.

The Koc values of test substance are 6.18, 9.49, 6.74, 18.7 and 3.37 cm3 g-1 in above soils respectively, and the average Koc values is 8.90 cm3 g-1

Key value for chemical safety assessment

Koc at 20 °C:

17.8