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Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2009-03-11 - 2009-12-10
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
batch equilibrium method
Media:
soil
Specific details on test material used for the study:
Molecular weight: 153.2 g/mol
Molecular formula: C7H11N3O
Purity: 99.9 %
Radiolabelling:
no
Test temperature:
20°C
Details on study design: HPLC method:
The analysis of the water phases (blank values and equilibrium concentrations) is based on the highly specific high performance liquid chromatography with mass-spectrometric detection (LC-MS/MS).
The analytical method for the determination of N-[(3(5)-Methyl-1H-pyrazol-1-yl)methyl]acetamide (P 70/05) in water was developed by SGS INSTITUT FRESLNIUS GmbH. The analytical method was proved to be valid within the course of the study.
The detection mode of N-[(3(5)-Methyl-1H-pyrazol-1-yl)methyl]acetamide (P 70/05) is based on an electrospray ionization technique (LSI positive).
Analytical monitoring:
yes
Details on matrix:
LUFA 2.1: July 15, 2009 (batch no.: F2.1 2909, SGS INSTITUT FRESENIUS GmbH identification: 010/9128400), depth of soil collcction was down to 20 cm), Germany, Rheinland- Pfalz, Dudenhofen, Am Hauhofcr Weg links, Nr. 3336/58, location of soil collection of no agricultural use, agricultural plant protection products not used for the sampling year and 4 former years, fertilization performed in 2007: 600 kg/ha CaO I 250 kg/ha MgO.
Soil type: silty sand (DIN) or sand (USDA)
LUFA 2.2: July 15, 2009 (batch no.: F2.2 2909, SGS INSTITUT FRESENIUS GmbH identification: 010/9128451), depth of soil collection was down to 20 cm), Germany, Rheinland- Pfalz, Hanhofen, Großer St riet, Nr. 585, meadow, agricultural plant protection products not used for the sampling year and 4 former years, fertilization performed in 2007: 600 kg/ha CaO + 250 kg/ha MgO.
Soil type: loamy sand (DIN and USDA)
• LUFA 2.3: July 16, 2009 (batch no.: F2.3 2909, SGS INSTITUT FRESENIUS GmbH identification: 010/9128452), depth of soil collection was down to 20 cm), Germany, Rheinland- Pfalz, Offenbach, Im Bildgarten Nr. 507, fallow soil and pumpkin, agricultural plant protection products not used for the sampling year and 4 former years, fertilization performed in 2005 (300 kg/ha): 12 % N, 12 % P205, 17 % K20.
Soil type: silty sand (DIN) or sandy loam (USDA)
The collection and sieving (2 mm screen) of soils was perfomied by LUFA Speyer, Obere Langgasse 40, 67346 Speyer, Germany. LUFA Speyer provided soil certificates for the German standard soils 2.1 (F2.1 2909), 2.2 (F2.2 2909) and 2.3 (F2.3 2909) including information on the history of the soils, geographical information on the German soil locations and characterization data.Soil aliquots were air dried at room temperature and stored in tightly closed all-plastic storage container at ambient temperature (approximately 20 °C). Prior to use the soil moisture analysis was carried out by heating soil aliquots at 105 °C overnight. The soil dry matter content was 99 %. Therefore, the degree of soil humidity was not taken into account for the preparation of the test systems.
Details on test conditions:
The test systems were composed of the test item dissolved completely in aqueous CaCl2 solution (0.01 mol/L) and soil, all placed in tightly closed all-plastic centrifuge bottles (125 mL). The co- solvent (methanol) added to the aqueous solution by test item dosing did not excced 0.1 vol. %.
A CaCl2 solution was used to minimize cation exchange.
Prior to use, experimental soils (sieved: < 2mm, air dried, soil moisture of 1 %) were equilibrated using 0.01 mol/L CaCl2 solution. Equilibration of soil was carried out by shaking (200 strokes/min) a calculated amount of soil with a volume of 59 mL of 0.01 mol/L CaCl2 solution for overnight (17 h) before the day of the experiment.
Afterwards a calculated volume of the test item solution (1 ml.,; 6.35 f.tg/mL P 70/05) was added to the slurry. By the addition of the test item solution the aqueous phase of the slurry was adjusted to 60 mL and the aimed test concentration of 0.1 mg/L P 70/05 was reached.
The soil and treated 0.01 mol/L CaCl2 solution were gently tumbled. The agitation device kept the soil in suspension during shaking (200 strokes/min). Soil (solid phase) and aqueous phase weic separated by centrifugation (4000 rpm for 5 min) and the aqueous phase removed as much as possible. The volume of the removed aqueous phase was recorded.
The adsorption equilibrium time was set to 24 hours.
The experiment was conducted at 20 + 2 °C in the dark, using analytical grade P 70/05, namely N- [(3(5)-Methyl-1H-pyrazol-1 -yl)methyl]acetamide.
Each test system was prepared in triplicate.
For the experiment three German Standard soils were used (sec section 7.1). The experimental soils were selected by the Sponsor, as was the test concentration.
The ratio of aqueous CaCl2 solution to dry soil for the adsorption test was:
• ratio 1:1 60 mL aqueous solution and 60 g dry soil
• ratio 5:1 60 mL aqueous solution and 12 g dry soil
The distribution of N-[(3(5)-Methyl-1H-pyrazol-1-yl)methyl]acetamide (P 70/05) between the water phase and the solid phase was investigated. LC-MS/MS was used for the analysis of the equilibrium concentration in the water phases. The adsorbed N-[(3(5)-Methyl-1H-pyrazol-1-yl)methyl]acetamide (P 70/05) in the solid phase (soil) was calculated.
Adsorption Test
The selection of solution/soil ratios was performed on
• ratio 1:1 60 mL aqueous solution and 60 g dry soil
• ratio 5:1 60 mL aqueous solution and 12 g dry soil
The test item concentration was adjusted to 0.1 mg/L. The experimental soils were pre-conditioned (see section. The test systems were tumbled (20 ± 2 °C in the dark, laboratory shaker at 200 strokes/min, 125 mL all-plastic centrifuge vessel) for 24 hours.
A time period of 24 hours maximum was assumed to be sufficient for reaching equilibrium.
After centrifugation (4000 ipm for 5 min) specimen aliquots of the supernatants were filtered using a membrane filter (OA, 0.45 pm). Specimen aliquots of 0.05 mL, taken at the 24 hours time point, were diluted with 0.95 mL of methanol/water/formic acid; 10/90/0.1, v/v/v and subjected to LC- MS/MS analysis.
Sample No.:
#1
Duration:
24 h
Temp.:
20 °C
Key result
Sample No.:
#1
Type:
Koc
Value:
2 L/kg
pH:
5.57
Temp.:
20 °C
Matrix:
LUFA 2.1
% Org. carbon:
0.74
Remarks on result:
other: ratio 1:1
Key result
Sample No.:
#2
Type:
Koc
Value:
7.5 L/kg
pH:
6.48
Temp.:
20 °C
Matrix:
LUFA 2.2
% Org. carbon:
2.09
Remarks on result:
other: ratio 1:1
Key result
Sample No.:
#2
Type:
Koc
Value:
10 L/kg
pH:
6.48
Temp.:
20 °C
Matrix:
LUFA 2.2
% Org. carbon:
2.09
Remarks on result:
other: ratio 5:1
Key result
Sample No.:
#3
Type:
Koc
Value:
34.9 L/kg
pH:
7.09
Temp.:
20 °C
Matrix:
LUFA 2.3
% Org. carbon:
0.97
Remarks on result:
other: ratio 1:1
Key result
Sample No.:
#3
Type:
Koc
Value:
34.5 L/kg
pH:
7.09
Temp.:
20 °C
Matrix:
LUFA 2.3
% Org. carbon:
0.97
Remarks on result:
other: ratio 5:1
Recovery of test material:
The recovery of N-[(3(5)-Methyl-1H-pyrazol-1-yl)methyl]acetamide (P 70/05) in the 0.01 mol/L CaCl2 solution (pH-value: 6.34) at a test concentration of 0.1 mg/L was 101.2 % (RSD of 0.4 %) after agitation for 24 hours at 20 °C in the dark.
Sample no.:
#1
Duration:
24 h
% Adsorption:
1
Remarks on result:
other: ratio 1:1
Sample no.:
#1
Duration:
24 h
% Adsorption:
0
Remarks on result:
other: ratio 5:1
Sample no.:
#2
Duration:
24 h
% Adsorption:
14
Remarks on result:
other: ratio 1:1
Sample no.:
#2
Duration:
24 h
% Adsorption:
4
Remarks on result:
other: ratio 5:1
Sample no.:
#3
Duration:
24 h
% Adsorption:
25
Remarks on result:
other: ratio 1:1
Sample no.:
#3
Duration:
24 h
% Adsorption:
6
Remarks on result:
other: ratio 5:1
Transformation products:
not measured
Validity criteria fulfilled:
yes
Conclusions:
N-[(3(5)-Melhyl-1H-pyrozol-1-yl)methyl]acetamide (P 70/05) showed a low tendency (o adsorb onto the experimental soils.
The adsorption coefficients on the basis of soil organic carbon content (Koc) were calculated to be:
• LUFA 2.1 soil lest system 2.0 mL/g (ratio L1) at 0.74 % org. carbon
• LUFA 2.2 soil test system 7.5 mL/g (ratio 1:1) at 2.09 % org. carbon
• LUFA 2.3 soil test system 34.9 mL/g (ratio 1:1) at 0.97 % org. carbon
Executive summary:

The extent of adsorption of N-[(3(5)-Methyl-1H-pyrazol-1 -yl)methyl]acetamidc (P 70/05) was studied on basis of the OECD/OCDH Guideline no.106 for the testing of chemicals, adopted January 21, 2000. The study was conducted with analytical grade N-[(3(5)-Methyl-lH-pyrazol-l-yl)mcthylJacetamide (99.9 %) test item.

Following the equilibration of the three German soil systems (soil textures according to DIN/US DA classification were: silty sand/sand for TUFA 2.1 soil, loamy sand for LUFA 2.2 soil, silty sand/sandy loam for TUFA 2.3 soil) with 60 mL of 0.01 mol/L CaCl2, the lest item was applied in 0.01 mol/T CaCI2. The co-solvent (methanol) added to the aqueous solution by test item dosing did not excced 0.1 vol, %.

The adsorption test was performed on two soil/solution ratios of 1:1 (60 mT of 0.01 mol/L CaCl; and 60 g dry soil) and 5:1 (60 mL of 0.01 mol/L CaCI2and 12 g diy soil) using one test concentration of N-[(3(5)-Methyl-l H- pyrazol-1 -yl)methyl]acetamide (0.1 mg/L).

After agitation for 24 hours at 20 °C ill ihe dark, the distribution of N-[(3(5)-Methyl-lH-pyrazol-1-yl)melhyl]- acetamide (P 70/05) between the aqueous phase and the solid phase (soil) was assayed. LC-MS/MS was used for the analysis of the equilibrium concentration in the aqueous phases. The adsorbed N-[(3(5)-Methyl-1H-pyrazol- 1 -yl)methyl]acetamide (P 70/05) in the solid phase (soil) was calculated,

N-[(3(5)-Melhyl-1H-pyrazol-l-yl)methyl]acetamide (P 70/05) showed a low tendency to adsorb onto the experimental soils.

The adsorption coefficients on the basis of soil organic carbon content (Koc) were calculated to be:

     LUFA 2.1 soil lest system             2.0 mL/g (ratio L1) at 0.74 % org. carbon

     LUFA 2.2 soil test system             7.5 mL/g (ratio 1:1) at 2.09 % org. carbon

     LUFA 2.3 soil test system             34.9 mL/g (ratio 1:1) at 0.97 % org. carbon

Endpoint:
adsorption / desorption: screening
Remarks:
other: Adsorption modeling
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2014
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable calculation method. Meets generally accepted scientific standards, well documented and acceptable for assessment.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6
Qualifier:
according to
Guideline:
other: Guidance on information requirements and chemical safety assessment, Chapter R.6: QSARs and grouping of chemicals, ECHA, 2008
Deviations:
not applicable
Principles of method if other than guideline:
For calculation of the soil adsorption coefficient (koc) of MPA the EPI (Estimation Programs Interface) Suite™, a Windows®-based suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC), was used.
The included program KOCWIN estimates the koc using two different estimation methodologies:
1. the Sabljic molecular connectivity method with improved correction factors
2. the traditional method based on log KOW

The Sabljic molecular connectivity method is solely based on the Molecular Connectivity Index (MCI) which is a method that runs directly from structure to activity. Molecular Connectivity Indices are representation of molecular structure. The molecule is regarded as a sum of the bonds connecting pairs of atoms which are encoded by the cardinal number (delta) and represents the count of all bonded atoms other than hydrogen. The molecule is than splitted into fragments which are encoded by the corresponding delta values. The delta value of each atom forming a bond pair designate a bond value and these values are then summed over all the bonds to calculate the molecular connectivity index.

The traditional method using measured Kow values uses correlations between the log Kow and the Koc. For polar and non-polar compunds separate regression equations are used.
For non-polar compounds: log Koc = 0.8679 log Kow - 0.0004
For polar compounds correction factors are implemented.
Type of method:
other: Adsorption modeling
Media:
other: not applicable
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):
not applicable
Test temperature:
not applicable
Details on study design: HPLC method:
not applicable
Details on sampling:
not applicable
Details on matrix:
not applicable
Details on test conditions:
not applicable
Computational methods:
See "Principles of method if other than guideline"
Type:
log Koc
Value:
1.473
Remarks on result:
other: MCI method
Type:
log Koc
Value:
1.088
Remarks on result:
other: log Kow method
Details on results (HPLC method):
not applicable
Adsorption and desorption constants:
not applicable
Recovery of test material:
not applicable
Concentration of test substance at end of adsorption equilibration period:
not applicable
Concentration of test substance at end of desorption equilibration period:
not applicable
Details on results (Batch equilibrium method):
not applicable
Statistics:
not applicable

1. Results:

SMILES : O=C(C)NCn1nccc1C

MOL FOR: C7 H11 N3 O1

MOL WT : 153.19

Soil Adsorption Coefficient (KOCWIN v2.00):

Koc : 29.71 L/kg (MCI method)

Log Koc: 1.473 (MCI method)

Koc : 12.24 L/kg (Kow method)

Log Koc: 1.088 (Kow method)

2.Applicability domain of the model (as given in the EPI SUITE User's Guide):

 

Currently there is no universally accepted definition of model domain.

Following minimum and maximum values for molecular weight are given:

 

Training Set Molecular Weights:

Minimum MW:  32.04

Maximum MW:  665.02

Average MW:  224.4

 

Validation Molecular Weights:

Minimum MW:  73.14

Maximum MW:  504.12

Average MW:  277.8

3. Statistical Accuracy (as given in the EPI SUITE User's Guide):

 

The following table gives statistical information for the MCI (Molecular Connectivity Index, first-order) training and validation Datasets.  The statistics pertain to the experimental log Koc and the MCI estimated log Koc:

 

 

MCI Methodology

 

 

 

 

 

 

 

 

Training

Training

Validation

 

 

No Corrections

with Corrections

Data set

 

 

 

 

 

number

 

69

447

158

r2corr coef

 

0.967

0.900

0.850

std deviation

 

0.247

0.340

0.583

avg deviation

 

0.199

0.273

0.459

The following table gives statistical information for the log Kow-based regression: training and validation sets.  The statistics pertain to the experimental log Koc and the Log Kow estimated log Koc:

 

 

Log Kow Methodology

 

 

 

 

 

 

 

 

Training

Training

Validation

 

 

No Corrections

with Corrections

Data set

 

 

 

 

 

number

 

68

447

150 **

r2corr coef

 

0.877

0.855

0.778

std deviation

 

0.478

0.396

0.679

avg deviation

 

0.371

0.307

0.494

4. Adequacy of prediction

The substance MPA falls within the applicability domain described above and, therefore, the predicted value can be considered reliable.

Validity criteria fulfilled:
not applicable
Conclusions:
It can be concluded that MPA is not very likely to adsorb to soil or sediment (Koc = 12.24 - 29.71 L/kg). The KOC values derived with EPISuite™, based on the MCI-model and the Kow method, can be considered reliable for both modelling and environmental fate assessments.
Executive summary:

The adsorption coeffcient log Koc of MPA was determined by a non-experimental calculation method.

MPA is a very water soluble, organic substance.

The calculated KOC values were 1.088 (log Kow method) and 1.473 (MCI method).

According to the EPI SUITE User's Guide, the MCI methodology is somewhat more accurate than the Log Kow methodology, although both methods yield good results.

Description of key information

Calculation of log Koc:

For calculation of the soil adsorption coefficient (koc) of  N-(3(5)-Methyl-1 H-pyrazol-1 -yl-methyl)-acetamid the EPI (Estimation Programs Interface) Suite™, a Windows®-based suite of physical/chemical property and environmental fate estimation programs developed by the EPA’s Office of Pollution Prevention Toxics and Syracuse Research Corporation (SRC), was used.

Results log Koc: 1.473 (Koc: 29.71 L/kg)

Experimental estimation of Adsorption on soil:

N-[(3(5)-Melhyl-1H-pyrozol-1-yl)methyl]acetamide (P 70/05) showed a low tendency to adsorb onto the experimental soils.

The adsorption coefficients on the basis of soil organic carbon content (Koc) were calculated to be:

•       LUFA 2.1 soil lest system       2.0 mL/g (ratio L1) at 0.74 % org. carbon

•       LUFA 2.2 soil test system       7.5 mL/g (ratio 1:1) at 2.09 % org. carbon

•       LUFA 2.3 soil test system       34.9 mL/g (ratio 1:1) at 0.97 % org. carbon

Key value for chemical safety assessment

Koc at 20 °C:
34.9

Additional information