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Adsorption / desorption

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Reference
Endpoint:
adsorption / desorption
Remarks:
adsorption
Type of information:
calculation (if not (Q)SAR)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
accepted calculation method
Justification for type of information:
Data is from computational model developed by USEPA
Qualifier:
according to
Guideline:
other: Modeling database
Principles of method if other than guideline:
Prediction done using KOCWIN Program (v2.00)
GLP compliance:
not specified
Type of method:
other: MCI Method
Media:
soil
Radiolabelling:
not specified
Test temperature:
25 deg.C
Analytical monitoring:
not specified
Key result
Type:
Koc
Value:
108 000 L/kg
Temp.:
25 °C
Remarks on result:
other: Log Koc= 5.0334 (estimated by MCI method)
Transformation products:
not specified

KOCWIN Program (v2.00) Results:

==============================

SMILES : O=C(Nc(cccc1N(=O)(=O))c1)c(c(O)c(N=Nc(c(OC)ccc2C(=O)Nc(cccc3)c3)c2)c(

c4ccc5)c5)c4

CHEM : 2-Naphthalenecarboxamide, 3-hydroxy-4- 2-methoxy-5- (phenylamino)car

bonyl phenyl azo -N-(3-nitrophenyl)-

MOL FOR: C31 H23 N5 O6

MOL WT : 561.56

--------------------------- KOCWIN v2.00 Results ---------------------------

Koc Estimate from MCI:

---------------------

First Order Molecular Connectivity Index ........... : 20.334

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 11.1998

Fragment Correction(s):

2 Nitrogen to non-fused aromatic ring ... : -1.0450

1 Ether, aromatic (-C-O-C-) ........... : -0.6791

1 Nitro (-NO2) ......................... : -0.4889

1 Azo (-N=N-) ......................... : -0.6475

2 Misc (C=O) Group (aliphatic attach).... : -3.2093

1 Aromatic Hydroxy (aromatic-OH) ....... : -0.0966

Corrected Log Koc .................................. : 5.0333

Estimated Koc: 1.08e+005 L/kg <===========

Validity criteria fulfilled:
not specified
Conclusions:
The soil adsorption coefficient i.e Koc value of test chemical was estimated to be 108000 L/kg (log Koc= 5.0333) by means of MCI method (at 25 deg C). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.
Executive summary:

KOCWIN model of Estimation Programs Interface was used to predict the soil adsorption coefficient i.e Koc value of test chemical. The soil adsorption coefficient i.e Koc value of test chemical was estimated to be 108000 L/kg (log Koc= 5.0333) by means of MCI method (at 25 deg C). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

Description of key information

KOCWIN model of Estimation Programs Interface was used to predict the soil adsorption coefficient i.e Koc value of test chemical. The soil adsorption coefficient i.e Koc value of test chemical was estimated to be 108000 L/kg (log Koc= 5.0333)by means of MCI method (at 25 deg C). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
108 000

Additional information

Various predicted data of the test chemical and various supporting studies for its structurally similar read across substance were reviewed for the adsorption end point which are summarized as below:

 

In aprediction done using theKOCWIN Programof Estimation Programs Interface was used to predict the soil adsorption coefficient i.e Koc value of test chemical. The soil adsorption coefficient i.e Koc value of test chemical was estimated to be 108000 L/kg (log Koc= 5.0333) by means of MCI method (at 25 deg C). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

The Soil Adsorption Coefficient i.e Koc value of test chemical was estimated using Adsorption Coefficient module program as Koc 130164, 376479, 456237, 466028, 467029, 467129, 467138, 467133, 467069, 466430, 460126, 405070, 178845, 18490 and 496 at pH range 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14, respectively (logKoc value ranges from 2.7 ± 1.0 to 5.7 ± 1.0) (ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017)).. The logKoc value (logKoc = 5.7 ± 1.0 at pH 7.0) indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

In an another prediction done by using ChemSpider Database (2017), the Soil Adsorption Coefficient i.e Koc value of test chemical was estimated. The adsorption coefficient (Koc) value of test chemical was estimated to be 12281.00 (Log Koc = 4.089) at pH 5.5 and 11578.73 (logKoc = 4.063) 7.4, respectively. This Koc value indicates that the test chemical has a strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.

 

Additional soil adsorption coefficient i.e Koc value of test chemicalwas estimated using the SciFinder database (2017).The soil adsorption coefficient i.e Koc value of test chemical was estimated to be 80200, 96800, 98800, 99000, 99100, 99000, 98600, 94900 at pH range 1, 2, 3, 4, 5-7, 8, 9 and 10, respectively (logKoc value ranges from 4.904 to 4.996) (at 25 deg C). This logKoc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

From CompTox Chemistry Dashboard using OPERA (OPEn (quantitative) structure-activity Relationship Application)  V1.02 model in which calculation based on PaDEL descriptors (calculate molecular descriptors and fingerprints of chemical), the adsorption coefficient i.e KOC for test chemical was estimated to be 14500 L/kg (log Koc = 5.161).The predicted KOC result based on the 5 OECD principles. This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

In a supporting weight of evidence study from authoritative database (2017) for the test chemical,adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of test chemical. The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test chemical was estimated to be 230000 (Log Koc = 5.361). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

For the test chemical, adsorption study was conducted for estimating the adsorption coefficient (Koc) value of test chemical (HSDB, 2017). The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test chemical was estimated to be 130000 (Log Koc = 5.113). This Koc value indicates that the test chemical has a very strong sorption to soil and sediment and therefore have negligible migration potential to ground water.

 

On the basis of above overall results for test chemical, it can be concluded that the log Koc value (at pH 7.0) of test chemical was estimated to be ranges from 4.063 to 5.7 ± 1.0, respectively, indicating that the test chemicalhas a strong to very strong sorption to soil and sediment and therefore have negligible to slow migration potential to ground water.