Sodium hydrogen m-sulphonatobenzoate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Version / remarks:

22 Jan 2001

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

30 May 2008

Deviations:

yes

Remarks:

The reference item mix was not dissolved in the eluent but in a similar eluent composition: methanol/10 mM citrate buffer/water 50/45/5 % v/v/v instead of methanol/10 mM citrate buffer 55/45 % v/v.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

Name sodium 3-sulfobenzoate
Batch no. 170103
Appearance White crystalline powder
Composition Sodium 3-Sulfobenzoate
CAS No. 17625-03-5
EINECS-No. 241-602-5
Molecular formula C7H5SO5Na
Molecular weight 224.17 g/mol
Purity > 99.0% (Titration with NaOH, Glass indicating electrode, Calomel reference electrode)
Homogeneity totally homogeneous
Expiry date 14. Feb. 2019
Storage Room Temperature (20 ± 5°C), keep away from humidity

Radiolabelling:

no

Test temperature:

25 ± 0.5 °C

Details on study design: HPLC method:

Reference Items
The substances which have been chosen taking into account the retention time of the test item sodium 3-sulfobenzoate are presented below. The reference items were dissolved in methanol and mixed with methanol to result in a solution with a composition similar to the mobile phase (methanol/10 mM citrate buffer/water 50/45/5 % v/v/v).

Substance CAS purity concentration injected
Acetanilid 103-84-4 99 % 1000 mg/L
Phenol 108-95-2 ≥99.0 % 1000 mg/L
Methylbenzoate 93-58-3 ≥99.5 % 1000 μL/L
3,5-Dinitrobenzamide 121-81-3 99.2 % 1000 mg/L
Naphthalene 91-20-3 ≥99.7 % 1000 mg/L
1,2,3-Trichlorobenzene 87-61-6 99.0 % 1000 mg/L
Pyrazophos 13457-18-6 98.5 % 1000 mg/L


Chemicals
Water
Water, H2O, HPLC grade.

10 mM Citrate Buffer
961.2 mg of citric acid monohydrate and 586.6 mg NaOH were dissolved in 400 mL HPLC grade water. pH was adjusted to 6.00 with NaOH solution and volume was filled up to 500 mL. 960.9 mg of citric acid monohydrate were dissolved in 400 mL HPLC grade water. pH was adjusted to 6.05 with NaOH solution and volume was filled up to 500 mL.

Methanol
Methanol, CH3OH, HPLC grade.

Sodium Nitrate
NaNO3, ≥ 99.5 %, 1000 mg/L in demineralised water, used as dead time marker.

Mobile Phase
A mixture of 55% methanol and 45% 10 mM citrate buffer pH 6, isocratic, was used. 550 mL methanol were mixed with 450 mL buffer. The temperature was held constant at 25.0 ± 0.5 °C by use of a HPLC column oven.

Test Item Solutions
Three test item solutions were prepared by weighing 20.0 mg sodium 3-sulfobenzoate into a 20 mL flask and filling up to 20.0 mL with mobile phase. 0.1 mL of each of these solutions was mixed with 0.9 mL mobile phase in a HPLC vial, resulting in solutions with test item concentrations of 100 mg/L, which were used for the measurements. Batch 20180202 was used for the pre-test, determination with batch 20180208 was not evaluable due to unsatisfactory column performance, batch 20180313 was used for the log KOC determination.

Test System

HPLC_7
Components:
- Solvent Rack
- Pump LPG-3400SD
- Autosampler WPS-3000TSL
- Column Compartment TCC-3200 with 6-fold column switch valve
- UV-Detector DAD-3000.

Manufacturer: Thermo Fisher Scientific
Software: CHROMELEON 6.80 SR15b Build 4981
Usage and calibration followed the corresponding SOP 114 00 529 in the current edition.

Method parameters HPLC
Column: Reprosil PurCN 125*4.6 mm, SN 50318 290202 with precolumn Phenomenex SecurityGuard CN, 4x3 mm
Eluent: isocratic, methanol/10 mM citrate buffer pH 6 55/45 (% v/v), degassed
Flow rate: 0.8 mL/min
Injection volume: 10 μL
Column temperature: 25.0 ± 0.5 °C
Wavelength for evaluation: 220 nm (reference mix); 254 nm (test item)

Analytical monitoring:

yes

Sample No.:

#1

Type:

log Koc

Value:

< 1.25 dimensionless

Remarks on result:

other: The test item elutes in the dead time of the method. This means, a determination will also result in a value <1.25 (log Koc of Acetanilide).

Details on results (HPLC method):

The test item elutes in the dead time of the method. This means, a determination will also result in a value “<1.25” (log Koc of Acetanilide).

Validity criteria fulfilled:

no

Conclusions:

The test item elutes in the dead time of the method. This means, a determination will also result in a value “<1.25” (log Koc of Acetanilide).

Executive summary:

Estimation of the adsorption coefficient on soil and on sewage sludge of sodium 3-sulfobenzoate has been performed using HPLC according to OECD 121 resp. EU C.19. The test item elutes in the dead time of the method. This means, a determination will also result in a value “<1.25” (log Koc of Acetanilide).

Description of key information

Estimation of the adsorption coefficient on soil and on sewage sludge of sodium 3-sulfobenzoate has been performed using HPLC according to OECD 121 resp. EU C.19. The test item elutes in the dead time of the method. This means, a determination will also result in a value “<1.25” (log Koc of Acetanilide).

Key value for chemical safety assessment

Koc at 20 °C:

1.25