Registration Dossier

Environmental fate & pathways

Adsorption / desorption

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
September 2014
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
comparable to guideline study
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)
GLP compliance:
not specified
Remarks:
Klimisch 1 study part of weight of evidence. GLP is not a requirement.
Type of method:
HPLC estimation method
Media:
soil
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: US Army armament research development and engineering center
- Purity: 98%


Radiolabelling:
no
Test temperature:
22 +/-3 °C
Details on study design: HPLC method:
The parameters used for analyzing DNAN samples were the following: a mobile phase ratio of 43:57 methanol and water and flow rate of 1 mL/ min. The column used for analysis was the Thermo Scientific Acclaim reversed phase C-18 column. The wavelengths used were 300 nm for DNAN, 254 nm for MENA, and 210 nm for 2,4-diaminoanisole.
Analytical monitoring:
yes
Matrix no.:
#1
Matrix type:
silt loam
% Clay:
25.6
% Silt:
65.5
% Sand:
8.9
% Org. carbon:
5.28
pH:
7.31
Matrix no.:
#2
Matrix type:
sandy loam
% Clay:
8.7
% Silt:
36.5
% Sand:
54.9
% Org. carbon:
3.88
pH:
6.67
Matrix no.:
#3
Matrix type:
silt loam
% Clay:
11.4
% Silt:
65.5
% Sand:
23.1
% Org. carbon:
2.68
pH:
6.66
Matrix no.:
#4
Matrix type:
loamy sand
% Clay:
4.4
% Silt:
20.4
% Sand:
75.2
% Org. carbon:
2.45
pH:
4.23
Matrix no.:
#5
Matrix type:
sandy loam
% Clay:
7.7
% Silt:
25.9
% Sand:
66.4
% Org. carbon:
2.42
pH:
6.69
Matrix no.:
#6
Matrix type:
sandy loam
% Clay:
11.2
% Silt:
35.7
% Sand:
53.1
% Org. carbon:
1.99
pH:
7.54
Matrix no.:
#7
Matrix type:
loam
% Clay:
16.4
% Silt:
42.3
% Sand:
41.4
% Org. carbon:
1.3
pH:
4.4
Matrix no.:
#8
Matrix type:
clay loam
% Clay:
32.3
% Silt:
44.9
% Sand:
22.8
% Org. carbon:
0.83
pH:
5.39
Matrix no.:
#9
Matrix type:
loam
% Clay:
4.1
% Silt:
12.5
% Sand:
83.4
% Org. carbon:
0.77
pH:
8.21
Matrix no.:
#10
Matrix type:
loam
% Clay:
26.8
% Silt:
33.5
% Sand:
39.7
% Org. carbon:
0.45
pH:
8
Matrix no.:
#11
Matrix type:
sandy clay loam
% Clay:
23.7
% Silt:
20.8
% Sand:
55.6
% Org. carbon:
0.34
pH:
7.83
Key result
Sample No.:
#1
Type:
Koc
Value:
112.7 other: cm3/g
pH:
7.31
Temp.:
23 °C
Matrix:
silt loam
% Org. carbon:
5.28
Key result
Sample No.:
#1
Type:
Kd
Value:
5.95 other: cm3/g
pH:
7.31
Temp.:
23 °C
Matrix:
silt loam
% Org. carbon:
5.28
Key result
Sample No.:
#2
Type:
Koc
Value:
162.9 other: cm3/g
pH:
6.67
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
3.88
Key result
Sample No.:
#2
Type:
Kd
Value:
6.32 other: cm3/g
pH:
6.67
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
3.88
Key result
Sample No.:
#3
Type:
Koc
Value:
126.5 other: cm3/g
pH:
6.66
Temp.:
23 °C
Matrix:
silt loam
% Org. carbon:
2.68
Key result
Sample No.:
#3
Type:
Kd
Value:
3.39 other: cm3/g
pH:
6.66
Temp.:
23 °C
Matrix:
silt loam
% Org. carbon:
2.68
Key result
Sample No.:
#4
Type:
Koc
Value:
178.6 other: cm3/g
pH:
4.23
Temp.:
23 °C
Matrix:
loamy sand
% Org. carbon:
2.45
Key result
Sample No.:
#4
Type:
Kd
Value:
4.38 other: cm3/g
pH:
4.23
Temp.:
23 °C
Matrix:
loamy sand
% Org. carbon:
2.45
Key result
Sample No.:
#5
Type:
Koc
Value:
84.8 other: cm3/g
pH:
6.69
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
2.42
Key result
Sample No.:
#5
Type:
Kd
Value:
2.05 other: cm3/g
pH:
6.69
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
2.42
Key result
Sample No.:
#6
Type:
Koc
Value:
250 other: cm3/g
pH:
7.54
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
1.99
Key result
Sample No.:
#7
Type:
Kd
Value:
4.96 other: cm3/g
pH:
7.54
Temp.:
23 °C
Matrix:
sandy loam
% Org. carbon:
1.99
Key result
Sample No.:
#7
Type:
Koc
Value:
228.3 other: cm3/g
pH:
4.4
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
1.3
Key result
Sample No.:
#7
Type:
Kd
Value:
1.89 other: cm3/g
pH:
4.4
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
1.3
Key result
Sample No.:
#8
Type:
Koc
Value:
240.6 other: cm3/g
pH:
5.39
Temp.:
23 °C
Matrix:
clay loam
% Org. carbon:
0.83
Key result
Sample No.:
#8
Type:
Kd
Value:
1.99 other: cm3/g
pH:
5.39
Temp.:
23 °C
Matrix:
clay loam
% Org. carbon:
0.83
Key result
Sample No.:
#9
Type:
Koc
Value:
121.4 other: cm3/g
pH:
8.21
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
0.77
Key result
Sample No.:
#9
Type:
Kd
Value:
0.93 other: cm3/g
pH:
8.21
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
0.77
Key result
Sample No.:
#10
Type:
Koc
Value:
424.4 other: cm3/g
pH:
8
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
0.45
Key result
Sample No.:
#10
Type:
Kd
Value:
0.94 other: cm3/g
pH:
8
Temp.:
23 °C
Matrix:
loam
% Org. carbon:
0.45
Key result
Sample No.:
#11
Type:
Koc
Value:
175.5 other: cm3/g
pH:
7.83
Temp.:
23 °C
Matrix:
sandy clay loam
% Org. carbon:
0.34
Key result
Sample No.:
#11
Type:
Kd
Value:
0.84 other: cm3/g
pH:
7.83
Temp.:
23 °C
Matrix:
sandy clay loam
% Org. carbon:
0.34
Details on results (HPLC method):
- Details of fitted regression line (log k' vs. log Koc): As 11 soils were tested, we cannot present here all the regression lines. R2 were between 0.29 and 0.96

For all studied soils, the Freundlich isotherm resulted in a highly significant fit to the data. Isotherms were similar in shape (Figures 35–38). Parameter n, an exponent in the Freundlich equation, was close for different soils, estimates averaging 0.76 with a range between 0.56 and 0.97. However, 95% confidence intervals of n estimates overlapped for the majority of the soils, indicating that they were not significantly different from each other at 95%. For three soils, Sassafras, Camp Guernsey and Camp Swift, n was not significantly different from 1 (resulting in a linear isotherm).
Linear regressions were also highly significant with slopes (Kd values) significantly different from zero. While, for the majority of soils, a Freundlich isotherm described DNAN adsorption the best, for four soils, Fort Harrison, Sassafras, Camp Guernsey, and Camp Swift, a linear isotherm resulted in a better fit to the data (Table 11). Normalizing estimated Kd values to OC content in the soil (KOC) resulted in a decrease in the percent standard deviation of the estimates (from 61% to 49%).
Validity criteria fulfilled:
yes
Conclusions:
Determined DNAN adsorption coefficients, both Kd and Kf, resulted in highly significant positive relationships with percent OC in the soil. No other measured soil properties, such as clay content, pH, or SSA, correlated with Kd or Kf values. Comparing DNAN with TNT adsorption coefficients for Catlin and Plymouth soils showed higher adsorption of DNAN in Plymouth soil (Kd of 4.38 cm3/ g for DNAN and 0.63 to 1.6 cm3/ g for TNT, depending on the method used), but less adsorption of DNAN in Catlin soil. Although the Freundlich parameters were similar for two compounds in the Catlin soil (Kf = 34.00, n = 0.62 for DNAN and Kf = 32.67, n = 0.60 for TNT), the Kd values were higher for TNT (17.9 vs. 5.95).
Executive summary:

In this study, it was measured how quickly DNAN dissolve in IM formulations and how solutions of these IM explosives interact with different types of soils. Because both dissolution and solution–soil interactions are determined by a suite of parameters, a multifaceted approach to studying these processes was used. Given a mass of IM compounds scattered on the range, the work will help determine the dissolved IM masses, their subsequent transport and fate, and their likelihood of reaching groundwater.

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
June 2011
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 106 (Adsorption - Desorption Using a Batch Equilibrium Method)
GLP compliance:
not specified
Remarks:
Klimisch 2 study part of weight of evidence. GLP is not a requirement.
Type of method:
HPLC estimation method
Media:
soil
Specific details on test material used for the study:
not specified
Radiolabelling:
not specified
Test temperature:
20°C
Details on study design: HPLC method:
Not specified
Analytical monitoring:
not specified
Details on sampling:
In a typical experiment, sorption was conducted in batch reactors (125 mL) borosilicate centrifuge tubes) containing the energetic chemical (50 mg/L) in 10mL water and soil (1.5 g) at 25°C. Samples were incubated statically, away from light and at room temperature and shaken twice a week to ensure aerobic conditions. At various time intervals, three replicates were sacrificed. After 2 h of deposition, the supernatant was withdrawn, filtered through a 0.45 μm Millipore filter (Millipore Corp., Bedford, MA), and analyzed by HPLC. Sorbed analyte was extracted from soil as described in the EPA SW-846 Method 8330 (USEPA, 2007). Briefly, soil was sonicated in deionized water at 20°C for 20 h. CaCl2 was used to facilitate separation of soil form the liquid phase prior to HPLC analysis. Recovery was calculated by adding the soluble and sorbed fractions of analytes using equation 1.
Key result
Type:
Kd
Value:
ca. 2.27 dimensionless
pH:
6.7
Temp.:
25 °C
Matrix:
soil
% Org. carbon:
ca. 2
Key result
Phase system:
other: Octanol-water
Remarks:
Octanol-water
Type:
Kp
Value:
ca. 38.02 other: not specified
Temp.:
25 °C
Transformation products:
yes
Remarks:
C7H7NO4, C6H4N2O5, C6H6N2O3, C6H4N2O4, C7H6N2O4, C7H4N2O4, C7H4N2O5, C7H4N2O5.

Kd = 2.27 (dimensionless)

Koc = Kd/foc where foc = fraction of soil organic content*.

foc = 0.02 kgoc x kgsolid-1 (ECHA CSR Guidance R16 Table R.16-8)

Therefore:

Koc =2.27/0.02 = 113.5

*Notes on Chemical-Specific Parameters – Physical and Chemical Properties (available from: https://fortress.wa.gov/ecy/clarc/FocusSheets/Physical&ChemicalParameters.htm)

Validity criteria fulfilled:
yes
Conclusions:
DNAN sorbed well to DRDC soil (Kd =2.27) and was found to be stable under experimental conditions.
Executive summary:

The present report summarizes findings on the environmental fate and ecological impact of DNAN. Firstly, aqueous solubility (Sw), octanol/water partition coefficients (Kow), sorption and stability were measured in two soils (DRDC-08 and DRDC-09 as provided by DRDC). Secondly, the toxicity of the chemical on various ecological receptors including earthworms, alga, and bacteria were determined. Preliminary findings showed that DNAN has a higher sorption coefficient indicating that this chemical will stay close to the soil surface. However it was found to photodegrade at wavelengths within the range of solar irradiation. Also indigenous bacteria in soil were found capable of degrading DNAN. These preliminary experimental findings indicate that DNAN may not stay in the open environment indefinitely, but rather they can photodegrade (soil surface) and biodegrade.


Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
2015
Reliability:
4 (not assignable)
Rationale for reliability incl. deficiencies:
secondary literature
Qualifier:
according to
Guideline:
EPA OPPTS 835.1220 (Sediment and Soil Adsorption / Desorption Isotherm)
GLP compliance:
not specified
Remarks:
Klimisch 4 study part of weight of evidence. GLP is not a requirement.
Type of method:
HPLC estimation method
Media:
soil
Specific details on test material used for the study:
SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: Defense Research and Development Canada
- Purity: 98.4%

Radiolabelling:
no
Test temperature:
25°C
Details on study design: HPLC method:
EQUIPMENT
- Apparatus: HPLC system
- Type: (HP 1200 series)
- Type, material and dimension of analytical (guard) column: C18 column
- Detection system: DAD detector

Samples (10 µL) were injected into a 2.5 lm-pore size Synergi-Polar column (2 mm ID 100 mm; Phenomenex) at 25°C. The solvent system was composed of CH3OH and HCOOH (0.05%) at a flow rate of 0.15 mL/ min using a gradient. For mass analysis, positive and negative electrospray ionization modes were used to produce protonated [M + H]+ and deprotonated [M–H]- molecular mass ions. Mass range was scanned from 40 to 500 Da.
Analytical monitoring:
yes
Details on matrix:
PROPERTIES
- Soil texture:
- % sand: 55.9 (PETAWAWA) 99.4 (TOPSOIL)
- % clay: 44.1 (PETAWAWA) 0.6 (TOPSOIL)
- pH: 4.9 (PETAWAWA) 6.1 (TOPSOIL)
- Organic carbon (%): 2.5 (PETAWAWA) 34.0 (TOPSOIL)
- CEC (meq/100 g): <10 (PETAWAWA) 35.0 (TOPSOIL)
Key result
Sample No.:
#1
Type:
Kd
Value:
9.1 L/kg
pH:
4.9
Temp.:
23 °C
Matrix:
PETAWAWA
% Org. carbon:
2.5
Key result
Sample No.:
#2
Type:
Koc
Value:
364 L/kg
pH:
4.9
Temp.:
23 °C
Matrix:
PETAWAWA
% Org. carbon:
2.5
Key result
Sample No.:
#3
Type:
Kd
Value:
73 L/kg
pH:
6.1
Temp.:
23 °C
Matrix:
TOPSOIL
% Org. carbon:
34
Key result
Sample No.:
#4
Type:
Koc
Value:
215 L/kg
pH:
6.1
Temp.:
23 °C
Matrix:
TOPSOIL
% Org. carbon:
34
Transformation products:
yes
No.:
#1
No.:
#2
No.:
#3
Validity criteria fulfilled:
yes
Conclusions:
Nitroaromatics (NACs) can sorb reversibly to organic matter, as dictated by their Kow, or to clay minerals through electron donor–acceptor complexes with the oxygen of the siloxane surface(s) of the clays or through complexation with exchangeable cations. The large Kd values measured in TOPSOIL soil despite its low clay content and the overall correlation observed between Kd’s and Kow’s confirm the binding of DNAN, 2-ANAN and 4-ANAN with organic matter. On the other hand, the markedly larger Koc values measured for all three amino compounds in PETAWAWA soil suggest the occurrence of interactions between the three amines and clay. The concurrent sorption of nitroaromatics to both organic matter and clay in natural soil was also recently demonstrated by Qu et al. (2011) using 2,4-DNT. As previously reported for other NACs (Haderlein et al., 1996), in the present study, reversible sorption decreased with the number of nitro groups and followed the order (DNAN > 2-ANAN > 4-ANAN > DAAN 0).
Executive summary:

Key initial abiotic and biotic reaction routes of DNAN were investigated and relevant physicochemical parameters (pKa, logKow, aqueous solubility (Sw), partition coefficient (Kd)) for the chemical and its products were determined. Reduction of DNAN with either zero valent iron or bacteria regioselectively produced 2-amino-4-nitroanisole (2-ANAN) which, under strict anaerobic conditions, gave 2,4-diaminoanisole (DAAN). Hydrolysis under environmental conditions was insignificant whereas photolysis gave photodegradable intermediates 2-hydroxy-4-nitroanisole and 2,4-dinitrophenol. Physicochemical properties of DNAN and its amino products drastically depended on the type and position of substituent(s) on the aromatic ring. Sw followed the order (TNT < DNAN < 2-ANAN < 4-ANAN < DAAN) whereas logKow followed the order (DAAN < 4-ANAN < 2-ANAN < DNAN < TNT). In soil, successive replacement of ANO2 by ANH2 in DNAN enhanced irreversible sorption and reduced bioavailability under toxic conditions.

Description of key information

Three values of Koc were presented. The lowest Koc was selected for the environmental assessment as it is believed to represent the worst-case scenario. The approach was selected based on the advice from ECHA1. Due to low Kow (1.58) it is expected that the substance will remain in the water and will not adsorb to organic matter (refer to Koc indicating high mobility in soil).

 

1.ECHA, Guidance on information requirements and Chemical Safety Assessment Chapter R.16: Environmental exposure assessment, Version 3.0 February 2016, available from: https://echa.europa.eu/documents/10162/13632/information_requirements_r16_en.pdf

Key value for chemical safety assessment

Koc at 20 °C:
113.5

Additional information