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Adsorption / desorption

The Soil Adsorption Coefficient i.e Koc value of test substance2-amino-5-hydroxynaphthalene-1,7-disulfonic acid(CAS no. 6535 -70 -2) was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 1 (log Koc = 0) at pH range 0-14 respectively. This Koc value indicates that the test substance2-amino-5-hydroxynaphthalene-1,7-disulfonic acidhas a negligible sorption to soil and therefore have rapid migration potential to groundwater.

Additional information

Adsorption / desorption

Various predicted data for the target compound chemical 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid (CAS No. 6535-70-2) were reviewed for the adsorption end point which are summarized as below:

 

The Soil Adsorption Coefficient i.e Koc value of test substance 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid (CAS no. 6535 -70 -2) was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 1 (log Koc = 0) at pH range 0-14 respectively (ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017).

 

In an another prediction done by using ChemSpider Database (2017),the Soil Adsorption Coefficient i.e Koc value of test substance 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid (CAS no. 6535 -70 -2) was estimated. The adsorption coefficient (Koc) value of substance 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid was estimated to be 1 (Log Koc = 0) at pH 5.5 and 7.4, respectively.

 

Additional soil adsorption coefficient i.e Koc value of test chemical2-amino-5-hydroxynaphthalene-1,7- disulfonic acid (CAS No. 6535 -70 -2)was estimated using the SciFinder database (American Chemical Society (ACS), 2017).The soil adsorption coefficient i.e Koc value of 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid was estimated to be 1 (log Koc = 0) (at 25 deg C).

 

In a supporting weight of evidence study from authoritative database (J-CHECK, 2017) for the read across chemical 4-aminobenzene-1-sulfonic acid (CAS no. 121-57-3),adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of read across chemical 4 -aminobenzene-1 -sulfonic acid. The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test substance 4-aminobenzene-1-sulfonic acid was estimated to be 10 (Log Koc = 1.0).

 

For the read across chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt (CAS no. 2611-82-7), adsorption study was conducted for estimating the adsorption coefficient (Koc) value of read across chemical 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt. The adsorption coefficient (Koc) value was calculated using a water solubility of 80,000 mg/l and a regression derived equation. The adsorption coefficient (Koc) value of test substance 1,3-Naphthalenedisulfonic acid, 7-hydroxy-8-((4-sulfo-1-naphthalenyl)azo)-, trisodium salt was estimated to be 9 (Log Koc = 0.954).

 

On the basis of above overall results for target chemical 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid (from EPI suite, ACD labs,ChemSpider and SciFinder database,2017), it can be concluded that the Koc value of test substance 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid was estimated to be 1 indicating that the test chemical 2-amino-5-hydroxynaphthalene-1,7-disulfonic acid has a negligible sorption to soil and therefore have rapid migration potential to groundwater.