Carbamic acid,N,N'-[1,3-phenylenebis[methyleneiminocarbonylimino(methyl-3,1-phenylene)]]bis-di-C11-14-isoalkylesters, C13-rich

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

batch equilibrium method

Media:

soil

Radiolabelling:

yes

Test temperature:

23± 2°C

Analytical monitoring:

yes

Matrix no.:

#1

Matrix type:

loam

% Org. carbon:

ca. 6.82

pH:

ca. 7.96

CEC:

ca. 27.1 other: cmol/kg

Matrix no.:

#2

Matrix type:

silty clay

% Org. carbon:

ca. 1.52

pH:

ca. 4.47

CEC:

ca. 10.5 other: cmol/kg

Matrix no.:

#3

Matrix type:

silty clay loam

% Org. carbon:

ca. 5.82

pH:

ca. 6.92

CEC:

ca. 21.2 other: cmol/kg

Matrix no.:

#4

Matrix type:

silt loam

% Org. carbon:

ca. 1.83

pH:

ca. 7.25

CEC:

ca. 6.59 other: cmol/kg

Matrix no.:

#5

Matrix type:

silt loam

% Org. carbon:

ca. 6.35

pH:

ca. 7.05

CEC:

ca. 23.3 other: cmol/kg

Details on matrix:

Five soils which characterized by different physic-chemical properties such as pH, organic carbon content and texture were selected. The test soils were black soil (A), red soil (B), paddy soil (C), moisture soil (D), meadow soil (E) which were collected from Heilongjiang, Yunan, Jiangsu, Henan province and Inner Mongolia.

Key result

Sample No.:

#1

Type:

Koc

Value:

ca. 96.8 dimensionless

pH:

7.96

% Org. carbon:

ca. 6.82

Key result

Sample No.:

#2

Type:

Koc

Value:

ca. 34.7 dimensionless

pH:

4.47

% Org. carbon:

ca. 1.52

Key result

Sample No.:

#3

Type:

Koc

Value:

ca. 49

pH:

6.92

% Org. carbon:

ca. 5.82

Key result

Sample No.:

#4

Type:

Koc

Value:

ca. 28.3

pH:

7.25

% Org. carbon:

ca. 1.83

Key result

Sample No.:

#5

Type:

Koc

Value:

ca. 56.1 dimensionless

pH:

7.05

% Org. carbon:

ca. 6.35

Adsorption and desorption constants:

Distribution coefficient Kd of five soil were 6.60, 0.527, 2.8, 0.517 and 3.56 cm3/g and Freudlich adsorption coefficient were 5.35, 2.16, 2.39, 2.06 and 4.16 µgI-I/n ( cm3 ) l/n /g

4.1.1 Linearity

The concentrations of 0.0603, 0.121, 0.302, 0.603, 1.21 and 1.51 mg/L work solutions were analyzed by HPLC-MS/MS method showed on Table 4. Linear calibration graph was constructed by the concentration versus peak area of the work solution. As the attached Figure 2 showed, the regression equation was y = 11343x + 968.28 and correlation coefficients (r²) was 0.9931.

4.1.2 Recovery and precision

(l) Recovery of aqueous phase The aqueous phases of spiked the test item were prepared by diluting the test item stock solution (1206 mg/L) with 0.01 M solution of CaC12, and the concentrations were 0.0603, 0.302, 1.51 mg/L. Every concentration of the spiked aqueous phase was repeated 5 times and analyzed by the method showed on the paragraph 3.5.9. The results showed that the recoveries of the spiked aqueous phases were 81.2 % ~ 113 % and the relative standard deviations (RSD) were 5.38 % ~ 12.7 % in attached Table 2. The chromatograms were showed on attached Figure 3.

(2) Recovery of adsorbed phase (soil) 50 g soil was spiked the test item stock solution and work solution. The concentrations of the test item in spiked soil were 0.0603, 0.302, 1.51 µg/g. The spiked soils were prepared and analyzed by the method showed on the paragraph 3.5.9. The results showed that the recoveries of the spiked soils were 88.8 % ~ 101 % and the relative standard deviations were 1.02 % ~ 6.18 % in attached Table 3. The chromatograms were showed in attached Figure 4.

 

4.1.3 Limit of quantification (LOQ) and limit of detection (LOD)

The LOQ of the test item in aqueous phase and soil were 0.0603 mg/L and 0.0603 µg/g respectively.

The LOD of the test item was 0.0182 mg/L.

4.2 TIER I-PRELIMINARY TEST

The results of tier 1 were showed in attached Table4 and plots of the percentage adsorption Ati of soilA and soil B versus time (ti) curves were showed on attached Figure5 and Figure6 respectively. The results showed the adsorption equilibration time was 48 h. Percentage adsorption reached above 25 %, when solution to soil ratio were 1/5 and 1/1 of soil A and soil B respectively.The results on attached Fig. 7 showed that there was no adsorption on the test vessels and the test item was stability in CaC12 solution during the test time.

 

4.3 TIER 2-ADSORPTION KINETICS AT ONE CONCENTRATION OF THE TEST ITEM

The results of adsorption kinetics were showed in attached Table 5. Plots of percentage adsorption ( Ati ) versus time (ti) curves of five soils were on Figure 8. Distribution coefficient Kd of five soil were 6.60, 0.527, 2.8, 0.517 and 3.56 cm3/g and the organic carbon normalized adsorption coefficient Koc were 96.8, 34.7, 49.0, 28.3 and 56.1 cm3/g respectively.

4.4 TIER 3-DESORPTION KINETICS

The results of desorption kinetics were showed in attached Table 6. Plots of percentage desorption (Dt ) versus time (ti) curves of soils A, B, C, D and E were on Figure 9. The desorption equilibration time was 48h. Desorption coefficient K_desof five soil were 151, 27.6, 155, 30.8 and 131 cm³/g and percentage desorption were 3.21, 3.50, 3.12, 3.14 and 3.68 % respectively in 48 h.

4.5 TIER 4-ADSORPTION ISOTHERMS

The results of Tier 4 and the Freundlich adsorption linearized equation showed in attached Table 7 and attached Table 8. Adsorption isotherms of five soil were in accordance with Freundlich adsorption linearized equation and correlation coefficients r²were both above 0.9. Freudlich adsorption coefficient of five soils were 5.35, 2.16, 2.39, 2.06 and 4.16 µg^I-I/n(cm³)^l/n/ g and the value of l/n were 0.890 ~ 1.08.

 

4.6 TIER 5-DESORPTION ISOTHERMS

The results of Tier 5 and the Freundlich desorption linearized equation showed in attached Table 9 and attached Table 10. Desorption isotherms of five soil were in accordance with Freundlich desorption linearized equation and correlation coefficients r²were both above 0.9. Freudlich desorption coefficient of five soils were 5.51, 33.0, 257, 29.1 and 316 µg^I-I/n(cm³)^l/n/ g and the value of l/n were 0.245 ~

1.04.

4.7 TIER 6-MASS BALANCE

The results of Tier 6 showed in attached Table 11 .When the nominal concentration was 1.21 mg/L at the beginning of the test, the mass balances of five soils were 90.8, 90.5, 90.3, 91.3 and 91.1 %.

Validity criteria fulfilled:

yes

Conclusions:

Distribution coefficient Kd of five soil were 6.60, 0.527, 2.8, 0.517 and 3.56 cm3/g and Freudlich adsorption coefficient were 5.35, 2.16, 2.39, 2.06 and 4.16 µgI-I/n ( cm3 ) l/n /g

Executive summary:

The test was designed to evaluate the adsorption of the test item on different soil types in order to predict its distribution in different environments conditions. The study procedures described in this report were designed to meet "The guidelines for the testing of chemical (HJ/T 153-2004)" and "The guidelines for the Testing of Chemicals-Physical-Chemical Properties and Physical Hazards", (China Environmental Science Press, 2013). In addition, the procedures were based on "Adsorption-Desorption Using a Batch Equilibrium Method" (the OECD guideline TGI 06).

Five soil which characterized by different physic-chemical properties such as pH, organic carbon content and texture were selected. The test soils were black soil (A), red soil (B), paddy soil (C),moisture soil (D), meadow soil (E) which were collected from Heilongjiang, Yunan, Jiangsu, Henan province and Inner Mongolia.

Results of preliminary test showed that adsorption equilibration time was 48 h and the optimal of soil/solution ratio were 1/5 of A, C and E and 1/1 of soil B and D respectively.

Results of adsorption kinetic test showed that distribution coefficient (Kd) of five soil were 6.60, 0.527, 2.8, 0.517 and 3.56 cm³/g and the organic carbon normalized adsorption coefficient (K_oc) were

96.8, 34.7, 49.0, 28.3 and 56.1 cm³/g respectively.

Results of desorption kinetic test showed that the desorption equilibration time was 48 h, desorption coefficient K_desof five soil were 151, 27.6, 155, 30.8 and 13l cm³/g and percentage desorption were

3.21 %, 3.50%, 3.12 %, 3.14 % and 3.68 % respectively in 48 h.

Results of adsorption isotherm test showed that adsorption isotherms of five soil were in accordance with Freundlich adsorption linearized equation and its correlation coefficients r²were both above 0.9, Freudlich adsorption coefficient of five soils were 5.35, 2.16, 2.39 ,2.06 and 4.16 µg^I-I/n(cm 3)^1/n/ g and the values of l/n were 0.890 ~ 1.08.

Results of desorption isotherm test showed that desorption isotherms of five soil were in accordance with Freundlich adsorption linearized equation. Freudlich desorption coefficient of five soils were 5.51, 33.0, 257, 29.1 and 316 µg^I-I/n(cm³)^{1 n}/ g and the value of l/n were 0.245 ~ 1.04.

Description of key information

Results of adsorption kinetic test showed that distribution coefficient (Kd) of five soil were 6.60, 0.527, 2.8, 0.517 and 3.56 cm³/g and the organic carbon normalized adsorption coefficient (K_oc) were 96.8, 34.7, 49.0, 28.3 and 56.1 cm³/g respectively.

Key value for chemical safety assessment

Koc at 20 °C:

96.8