Sulfonic acids, C6-8-alkane, sodium salts

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer reviewed data in the ICCA HPV program

Qualifier:

no guideline followed

Principles of method if other than guideline:

Sorption of surfactants on sediment from an artiticial pond. Organ carbon content of the sediment = 22%

GLP compliance:

not specified

Type of method:

batch equilibrium method

Media:

sediment

Test temperature:

25 °C

Analytical monitoring:

not specified

Type:

Koc

Value:

75 - 105

Temp.:

25 °C

% Org. carbon:

22

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Substance within applicability domain - fragment corrections available for relevant functional groups.

Principles of method if other than guideline:

The Koc was estimated for the 2 main constituents of the substance using KOCWIN v2.00 (Molecular Connectivity Index method).

Type of method:

other: Estimation using KOCWIN v2.00

Type:

Koc

Value:

10

Remarks on result:

other: C6 alkane sulfonate

Type:

Koc

Value:

31.52

Remarks on result:

other: C8 alkane sulfonate

OCWIN Program (v2.00) Results:

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

SMILES : S(=O)(=O)(O([Na]))CCCCCC

CHEM : 1-Hexanesulfonic acid, sodium salt

MOL FOR: C6 H13 O3 S1 Na1

Koc may be sensitive to pH!

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

NOTE: METAL (Na, Li or K) HAS BEEN REMOVED TO ALLOW ESTIMATION via MCI!

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 4.561

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 2.9773

Fragment Correction(s):

1 Sulfonic acid (-S(=O)-OH) ............. : -2.0000

Corrected Log Koc .................................. : 0.9773

Over Correction Adjustment to Lower Limit Log Koc ... : 1.0000

Estimated Koc: 10 L/kg <===========

KOCWIN Program (v2.00) Results:

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

SMILES : CCCCCCCCS(O([Na]))(=O)=O

CHEM : 1-Octanesulfonic acid, sodium salt

MOL FOR: C8 H17 O3 S1 Na1

Koc may be sensitive to pH!

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

NOTE: METAL (Na, Li or K) HAS BEEN REMOVED TO ALLOW ESTIMATION via MCI!

Koc Estimate from MCI:

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

First Order Molecular Connectivity Index ........... : 5.561

Non-Corrected Log Koc (0.5213 MCI + 0.60) .......... : 3.4986

Fragment Correction(s):

1 Sulfonic acid (-S(=O)-OH) ............. : -2.0000

Corrected Log Koc .................................. : 1.4986

Estimated Koc: 31.52 L/kg <===========

Description of key information

Estimated values of 10 and 31.52 have been calculated for the C6- and C8- alkane sulfonates, respectively using KOCWIN v2.00.

Key value for chemical safety assessment

Koc at 20 °C:

31.52

Additional information

Estimated values of 10 and 31.52 have been calculated for the C6- and C8- alkane sulfonates, respectively using KOCWIN v2.00. These values are supported by the experimental value of 75 L/kg derived for sodium octyl sulfate. It is reasonable to assume that alkyl sulfates and alkane sulfonates share a common sorption mechanism - mainly hydrophobic interactions due to the alkyl chains with no ionic interactions by the functional groups – especially considering the similarities in their structures.