3,9-dimethyl-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane 3,9-dioxide

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:

2016-03-02 till 2016-09-20

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))

GLP compliance:

no

Remarks:

Preliminary investigations (non-GLP) for the determination of the adsorption coefficient KOC on soil and on sewage sludge using high performance liquid chromatography (HPLC) were performed according to OECD 121

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

room temperature

Details on study design: HPLC method:

Analytical HPLC column (based on silica matrix) packed with a cyanopropyl solid phase containing non-polar and polar moieties coupled to DAD and MS. Acetonitrile : HPLC water (30 : 70 v/v) was used as mobile phase.

Key result

Remarks on result:

not determinable because of methodological limitations

Details on results (HPLC method):

In non-GLP measurements the test item had a much lower retention time than Acetanilide. Acetanilide is the reference compound given in the guideline with the lowest log KOC value (1.26 for soil and 1.52 for sewage sludge). Therefore, a determination of the log KOC value would only be possible by extrapolation, which provides significant inaccuracy for the study endpoint. Different concentrations of 10 mg/L, 20 mg/L and 40 mg/L of the test item were measured, to show correlation between the measured concentration and detector response (linearity).

Adsorption and desorption constants:

Result of preliminary investigations (non-GLP) for the determination of the adsorption coefficient KOC on soil and on sewage sludge:
log Koc, soil < 1.26, log Koc, sewage sludge < 1.52

Validity criteria fulfilled:

yes

Conclusions:

As the log KOC of the test item has been estimated as outside of the scope of this guideline, it was not possible to determine the adsorption coefficient (KOC) of the test item on soil and on sewage sludge exactly.
Therefore the Koc can only be estimated to be lower than the lowest reference values: log Koc, soil < 1.26 and log K oc, sewage sludge < 1.52

Description of key information

As the log Koc of the test item has been estimated as outside of the scope of this guideline, it was not possible to determine the adsorption coefficient (KOC) of the test item on soil and on sewage sludge exactly.

Therefore the Koc can only be estimated to be lower than the lowest reference values: log Koc, soil < 1.26 and log Koc, sewage sludge < 1.52

Key value for chemical safety assessment

Koc at 20 °C:

18.2