5-bromo-5-nitro-1,3-dioxane

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:

05-Nov-2018 to 25-Feb-2019

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 (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Specific details on test material used for the study:

Identification: 5-Bromo-5-nitro-1,3-dioxane
Batch (Lot) Number: 201807021
Expiry date: 30 Jun 2020 (expiry date) (taken from label)
Physical Description: White crystal powder
Purity/Composition: See Certificate of Analysis
Storage Conditions: At room temperature
Stability at higher temperatures: Stable, maximum temperature: 50°C, maximum duration: 120 minutes

Radiolabelling:

not specified

Test temperature:

Analytical Method
Column temperature 35°C +/- 1°C

Details on study design: HPLC method:

Analytical Conditions
Instrument Acquity UPLC system (Waters, Milford, MA, USA)
Detector Acquity UPLC TUV detector (Waters)
Column Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm (Waters)
Column temperature 35°C +/- 1°C
Injection volume 5 µL
Mobile phase 55/45 (v/v) methanol/buffer pH 7
Flow 0.4 mL/min
UV detection 210 nm

Key result

Sample No.:

#1

Type:

Koc

Value:

ca. 1.9 L/kg

pH:

7

Temp.:

35 °C

Matrix:

cyanopropyl stationary phase

Sample No.:

#1

Type:

log Koc

Value:

ca. 1.28 dimensionless

pH:

7

Temp.:

25 °C

Matrix:

cyanopropyl stationary phase

Details on results (HPLC method):

pKa Values
No pKa values for acidic and basic groups in the molecular structure of the test item in the logarithm range of 1 – 14 were calculated.

Koc HPLC Method
In the chromatogram of the test solution, one major peak and two small test item peaks were observed. The equation of the regression line was: log k’ = 0.327 x log Koc – 0.803 (r = 0.98, n = 16).

Validity criteria fulfilled:

yes

Conclusions:

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of 5-Bromo-5-nitro-1,3-dioxane. The Koc and log Koc values of the test item at pH 7 were:

Koc log Koc Peak Area %
Test item - peak 1 1.9 x 10 e1 1.28 96
Test item - peak 2 1.6 x 10 e4 4.21 1.8
Test item - peak 3 2.0 x 10 e4 4.30 1.8

Executive summary:

Information: Adsorption coefficient

Guideline: EC C.19 OECD 121

Result:     log Koc : 1.28 (area 96%)

log Koc : 4.21 (area 1.8%)

log Koc : 4.30 (area 1.8%)

HPLC method based on soil-adsorptionreference data

Description of key information

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of the test substance. The Koc value of the main species identified in the test item (96% peak area) at pH 7 was 19.

Key value for chemical safety assessment

Koc at 20 °C:

19