3,3,5,7,7-pentamethyl-1,2,4-trioxepane

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

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

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

Clear colourless liquid, purity 96.5%.

Radiolabelling:

no

Test temperature:

35 oC

Details on study design: HPLC method:

A HPLC with a spectrophotometric detector was used. Stationary phase: cyanopropyl chemically bound resin on silica basis. Mobile phase: 40/60 (v/v) methanol/water. A temperature controlled column 35 °C was used. The test was performed at neutral pH based on a computer estimated pKa (ionized <10% pH 5.5-7.5).
• The test was performed in duplicate. References were added as a mixture of 5 in methanol and mixed with the mobile phase. Reference blank: 5/95 (v/v) methanol/mobile phase.
• t0: formamide in methanol 5.1 g/l. blank: 10/90 (v/v) methanol/mobile phase.
• 1.3 g/l pentamethyl-trioxepane in mobile phase =stock. Dilute 10x =test. Blank: mobile phase.
Injection: mobile phase, ref., ref. blank, formamide sol., formamide blank, test (in duplicate), blank, ref., formamide sol.

The solutions were injected in the following sequence: mobile phase, the mixtures of reference substances, the reference blank solution, the formamide solution, the formamide blank solution, the test solution (in duplicate), the corresponding blank solution, the mixtures of reference substances and the formamide solution. The chromatograms of the formamide solution and the corresponding blank were recorded for 5 minutes. All other chromatograms were recorded for 50 minutes.

Key result

Sample No.:

#1

Type:

log Koc

Value:

1.7 dimensionless

pH:

7

Temp.:

35 °C

Key result

Sample No.:

#1

Type:

Koc

Value:

50 L/kg

pH:

7

Temp.:

35 °C

Details on results (HPLC method):

Analytical conditions:
Column: Hypersil BDS-CN; 150 x 4.6 (I.D.) mm; dp= um (Alltech, Deerfield, USA)
Column temperature: 35 oC
Mobile phase: 40/60 (v/v) Methanol/Milli-Q water
FLow: 1 ml/min
Detection: UV at 210 nm
Injection volume: 10 ul

T0=1.975 min (mean 1.976 and 1.973). regression line: log k’ =0.42 log Koc-1.08 (r=0.961, n=9)

Reference substances (log K_oc): Phenol (1.32), N,N-dimethylbenzamide (1.52), Methylbenzoate (1.80), 3,5-dinitrobenzamide (2.31), Naphtalene (2.75), Mercaptodimethur (3.10), Fenthion (3.31), Phenantrene (4.09) and 2,4-DDT (5.63). pentamethyl-trioxepane log K_oc: 1.70

Validity criteria fulfilled:

yes

Conclusions:

Koc 50 (log Koc 1.70) at 35 °C

Executive summary:

K_oc5.0*10¹ (log K_oc1.70) at 35 °C

Description of key information

Koc 50 (log Koc 1.70) at 35 °C

Key value for chemical safety assessment

Koc at 20 °C:

50

Additional information

[LogKoc: 1.7]