Strontium 3-hydroxy-4-[(1-sulfonato-2-naphthyl)azo]-2- naphthoate 5/2 hydrate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Type of information:

experimental study

Adequacy of study:

key study

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))

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Specific details on test material used for the study:

Molecular weight : 553.05
CAS Number : 15792-20-8
Description: Red powder
Batch : 070711
Purity: >= 96.4 %
Test substance storage: At room temperature in the dark
Stability under storage conditions : Stable
Expiry date: 11 July 2011

Radiolabelling:

no

Test temperature:

Column temperature: 35 °C +/- 0.5 °C

Details on study design: HPLC method:

Instrument: Alliance Separation Module 2695 (Waters, Milford, MA, USA)
Detector: Dual l\ Absorbance Detector 2487 (Waters)
Column: Hypersil BDS-CN, 150 mm x 4.6 mm i.d.; dp = 5 µm (Thermo, San Jose, CA, USA)
Column temperature: 35 °c ± 0.5 °c
Mobile phase: 55/45 (v/v) Methanol/citric acid buffer pH 6.0
Flow: 1 ml/min
Injection volume: 10 µI
UV detection: 210 and 516 nm


REFERENCE SUBSTANCES
- Identity: Phenol

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: A 944 mg/L stock solution of the test substance was prepared in DMSO. In order to dissolve the test substance completely the stock solution was gently heated. The test solution was prepared by adding 500 µL of the stock solution to a 5 mL volumetric flask. The flask was filled up to the mark with mobile phase. The final concentration of the test substance solution was 94.4 mg/L.

The test substance blank solution was prepared by adding 500 µI of DMSO to a 5 mL volumetric flask. The flask was filled up to the mark with mobile phase.

- Quantity of reference substances: A stock solution of the reference substance at a concentration of 1230 mg/L in methanol was used. The reference substance solution was prepared by adding 50 µL of the stock solution to a 5 mL volumetric flask. The flask was filled up to the mark with mobile phase.

The blank solution for the mixture of reference substances was prepared by adding 50 µL methanol to a 5 mL volumetric flask. This flask was also filled up to the mark with mobile phase.



REPETITIONS
- Number of determinations: The reference substance and test substance solutions were injected in duplicate. Blank solutions were analysed by single injection.

Key result

Type:

Koc

Value:

< 21 dimensionless

pH:

6

Temp.:

35 °C

Key result

Type:

log Koc

Value:

< 1.32 dimensionless

pH:

6

Temp.:

35 °C

Details on results (HPLC method):

In the chromatogram of the test substance solution, one test substance peak was observed both at a wavelength of 210 nm and the test substance specific wavelength of 516 nm. The peak at approximately 2 minutes was also observed in the chromatogram of the blank solution. Therefore, it was assumed that this peak did not derive from the test substance.

Koc at pH 6.0

 

Substance	tr,1	tr,2	mean tr (n=2)	logKoc	Koc	Area %
Formamide (to)	2.022	2.019	2.021
Phenol	2.227	2.223		1.32
Major component	1.677	1.677	1.677	<1.32	<21	100

 

 Conclusion:

The Koc and log Koc value of the major component of R507-2 is:

	pH 6.0
	Koc	logKoc
Major component	<21	<1.32

Validity criteria fulfilled:

yes

Conclusions:

The Koc and log Koc value of the major component of R507-2 is: < 21 and < 1.32 respectively.

Executive summary:

The Koc and log Koc value of the major component of R507-2 is: < 21 and < 1.32 respectively.

Description of key information

The Koc and log Koc value of the major component of R507-2 is: < 21 and < 1.32 respectively.

Key value for chemical safety assessment

Koc at 20 °C:

21

Additional information

[LogKoc: 1.32]