Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2nd August 2018 to 31st August 2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
other: MEP The Guidelines for the testing of chemicals No.106. Adsorption - Desorption Using a Batch Equilibrium Method (2013)
Qualifier:
according to guideline
Guideline:
OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)
Qualifier:
according to guideline
Guideline:
other: GB/T 21851-2008, Chemicals-Adsorption-desorption using a batch equilibrium method
GLP compliance:
yes
Type of method:
batch equilibrium method
Media:
soil

Test material

Constituent 1
Chemical structure
Reference substance name:
1-{[2-fluoro-6-(trifluoromethyl)phenyl]methyl}-5-iodo-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione
EC Number:
687-893-6
Cas Number:
1150560-54-5
Molecular formula:
C13H9F4IN2O2
IUPAC Name:
1-{[2-fluoro-6-(trifluoromethyl)phenyl]methyl}-5-iodo-6-methyl-1,2,3,4-tetrahydropyrimidine-2,4-dione
Test material form:
solid: particulate/powder

Study design

Test temperature:
20 - 25 oC

Batch equilibrium or other method

Analytical monitoring:
yes
Details on sampling:
Solution Preparation: 0.01 mol/L CaCl2 was prepared by dissolving 1.11 g CaCl2 into 1000 mL ultra water.

1) Test 1 - Preliminary Study
(a) Solution/soil ratio 5:1
5.0g soil with 25 mL solution (0.01 mol/L CaCl2) was agitated at 160rpm for at least 12 hours at 20-25 0C in order to achieve pre-equilibrium. Then 25μL of stock solution of 2000 mg/L was added to the aqueous phase to achieve a nominal concentration of 2mg/L. The another 24 hours agitation was run to reach adsorption equilibrium . Both the concentration of aqueous and oil phases were measured on 2nd, 4th, 6th and 24th hours to calculate the adsorption percentage and mass balance rate.
A blank run per soil with the same amount of soil with 0.01 mol/L CaCl2 solution (without test substance) were subjected to the same test procedure.

(b) Solution/soil ratio 25:1 - black soil and paddy soil
2.0g soil with 50mL solution (0.01 mol/L CaCl2) was agitated at 160rpm for at least 12 hours at 20-25 0C in order to achieve pre-equilibrium. Then 50μL stock solution of 2000 mg/L was added to the aqueous phase to achieve a nominal concentration of 2mg/L. The another 24 hours agitation was run to reach adsorption equilibrium . Both the concentration of aqueous and oil phases were measured on 2nd, 4th and 6th hours to calculate the adsorption percentage and mass balance rate.

2) Tier-2 absorption kinetics and desorption percentage at one single concentration
Solution/soil ratio 5:1 (red, moisture and aquic-brown) and 25:1 (black and paddy)
5.0g soil (red, moisture and aquic-brown) with 25mL solution (0.01 mol/L CaCl2) and 2.0g soil (black and paddy) with 50mL solution (0.01 mol/L CaCl2) were weighed into a 250ml centrifugal tube. After 12 hours equilibrium at 20-25 0C, 25μL (5:1) and 50μL (25:1) of stock solution of 2000 mg/L was added to the aqueous phase to achieve a nominal concentration of 2 g/L. The another 4 hours agitation was run to reach adsorption equilibrium. The volume of supernatant was recorded and an equal volume of 0.01 mol/L CaCl2 substituted for the desorption test. The concentration in the aqueous phase was measured on 2nd, 4th, and 20th hours to calculate desorption.

3) Tier-3 adsorption isotherms and desorption co-efficients
a) Adsorption isotherms
All 5 soils were used. Five test concentrations were run, 0.2, 0.4, 1.0, 2.0 and 5.0mg/L. A series of CaCl2 solution control units with concentrations of 0.2, 0.4, 1.0, 2.0 and 5.0mg/L were run in the same conditions.
b) Desorption co-efficients
The soil and aqueous phases were separated when adsorption equilibrium was reached. The volume of supernatant was recorded and replaced with an equal volume of 0.01mol/L CaCl2 for the desorption test. Another 4 hours agitation was run to achieve equilibrium.

Matrix propertiesopen allclose all
Matrix no.:
#1
Matrix type:
other: Paddy Soil
% Clay:
18.1
% Silt:
17.1
% Sand:
63.9
% Org. carbon:
1.96
pH:
3.88
Matrix no.:
#2
Matrix type:
other: Aquic Brown Soil
% Clay:
16.5
% Silt:
42.8
% Sand:
39.9
% Org. carbon:
2.06
pH:
5.47
Matrix no.:
#3
Matrix type:
other: Red Soil
% Clay:
53.8
% Silt:
28.5
% Sand:
16.8
% Org. carbon:
1.94
pH:
4.93
Matrix no.:
#4
Matrix type:
other: Black Soil
% Clay:
33.4
% Silt:
25.9
% Sand:
39.3
% Org. carbon:
2
pH:
6.54
Matrix no.:
#5
Matrix type:
other: Moisture Soil
% Clay:
24.6
% Silt:
24.2
% Sand:
50.9
% Org. carbon:
1.22
pH:
7.87
Details on matrix:
COLLECTION AND STORAGE
- Geographic location: Huai'an - Jiangsu Province, Shenyang - Liaoning Province, Qidong - Hanon
Province, Suihua - Heilongjiang Province and Heze - Shendong Province
- Storage conditions: Room Temperature
- Soil preparation: 2 mm sieved

PROPERTIES
- % sand (thin 0.2 - 0.02): 63.9, 39.9, 16.8, 39.3 and 50.9
- % sand (crude 2 - 0.2): 0.9, 0.8, 0.9, 1.4 and 0.3
- % silt: 17.1, 42.8, 28.5, 25.9 and 24.2
- % clay: 18.1, 16.5, 53.8, 33.4 and 24.6
- pH: 6.88, 5.47, 4.93, 6.54 and 7.87
- Organic carbon (%): 1.96, 2.06, 1.94, 2.00 and 1.22
Duration of adsorption equilibrationopen allclose all
Sample No.:
#1
Duration:
4 h
Temp.:
20 - 25 °C
Sample No.:
#2
Duration:
4 h
Temp.:
20 - 25 °C
Sample No.:
#3
Duration:
4 h
Temp.:
20 - 25 °C
Sample No.:
#4
Duration:
4 h
Temp.:
20 - 25 °C
Sample No.:
#5
Duration:
4 h
Temp.:
20 - 25 °C
Duration of desorption equilibrationopen allclose all
Sample no.:
#1
Duration:
4 h
Temp.:
25 °C
Sample no.:
#2
Duration:
4 h
Temp.:
25 °C
Sample no.:
#3
Duration:
4 h
Temp.:
25 °C
Sample no.:
#4
Duration:
4 h
Temp.:
25 °C
Sample no.:
#5
Duration:
4 h
Temp.:
25 °C

Results and discussion

Adsorption coefficientopen allclose all
Key result
Sample No.:
#1
Type:
log Koc
Value:
3.03
Matrix:
Paddy soil
Key result
Sample No.:
#2
Type:
log Koc
Value:
2.82
Matrix:
Aquic brown soil
Key result
Sample No.:
#3
Type:
log Koc
Value:
2.38
Matrix:
Red soil
Key result
Sample No.:
#4
Type:
log Koc
Value:
3.28
Matrix:
Black soil
Key result
Sample No.:
#5
Type:
log Koc
Value:
2.56
Matrix:
Moisture soil

Results: Batch equilibrium or other method

Mass balance (%) at end of adsorption phaseopen allclose all
Sample no.:
#1
Duration:
6 h
% Adsorption:
90.8
Remarks on result:
other: Solution/soil ratio 25:1
Sample no.:
#4
Duration:
6 h
% Adsorption:
95.4
Remarks on result:
other: Solution/soil ratio 25:1
Sample no.:
#1
Duration:
24 h
% Adsorption:
100.7
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#2
Duration:
24 h
% Adsorption:
91.7
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#3
Duration:
24 h
% Adsorption:
90.2
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#4
Duration:
24 h
% Adsorption:
101.9
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#5
Duration:
24 h
% Adsorption:
88.3
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#1
Duration:
4 h
% Adsorption:
100.5
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#2
Duration:
4 h
% Adsorption:
99.1
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#3
Duration:
4 h
% Adsorption:
90.4
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#4
Duration:
4 h
% Adsorption:
106.3
Remarks on result:
other: Solution/soil ratio 5:1
Sample no.:
#5
Duration:
4 h
% Adsorption:
90.2
Remarks on result:
other: Solution/soil ratio 5:1

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Methyl Iodouracil has a moderate adsorption potential and the adsorption was deduced to be irreversible. 
Executive summary:

The HPLC was employed to determine the test item Methyl Iodouracil. The recovery test in 0.01 mol/L Ca Cl2 was set up at two concentrations, 0.1 and 5 mg/L. The mean recovery rate was in the range of 83.1 - 86% with RSD in the range 1.2 - 7.1%. The recovery test in soils was based on three concentrations 0.5, 1.0 and 50mg/kg. The mean recovery rate was in the range of 85.8 - 105.2% with RSD in the range 0.1 - 7.2%. The analytical method met the quality criteria. 


A batch equilibrium method was performed on the basis of MEP Guidelines for the Testing of Chemicals (2013) No. 106 Adsorption/desorption using a Batch Equilibrium Method. 


The red soil, moisture soil, aquic-brown soil, black soil and paddy soil were employed in the adsorption isotherm test, 5:1 was employed for the three former soils and 25:1 for the latter two. The equilibrium time was four hours. 


The concentrations were 0.2, 0.4, 1,2 and 5 mg/L. The log Koc of red soil, moisture soil, aquic-brown soil, black soil and paddy soil were 2.38, 3.03, 3.28, 2.56 and 2.82 mg/L respectively. With a desorption equilibrium time selection of 4 hours, the mean Kdes of red soil, moisture soil, aquic-brown soil, black soil and paddy soil were 179.9, 75.9, 76.2, 27.9 and 24.4 respectively.


The test iterm has a moderate adsorption potential and the adsorption was deduced to be irreversible.