2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 2010 - 2011

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Fully GLP- and guideline compliant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2011

Materials and methods

Test guideline

Test guideline 1

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

Test guideline 2

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

Test material

Test material information

Constituent 1

Reference substance name:

2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine

EC Number:

426-040-2

EC Name:

2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine

Cas Number:

25713-60-4

Molecular formula:

C 21 H 6 Br 9 N 3 O 3

IUPAC Name:

tris(2,4,6-tribromophenoxy)-1,3,5-triazine

Details on test material:

Name of test material (as cited in study report): "BTAC-245"
Chemical names: 2,4,6-tris(2,4,6-tribromophenoxy)-1,3,5-triazine
Hill formula: C21H6Br9N3O3
CAS No: 25713-60-4
Lot No.: 100907
Appearance: White powder
Purity: >99.5 %
Conditions of storage: Room temperature
Expiry date: Not available

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
PHYSICO-CHEMICAL PROPERTIES
The pKa of the test substance was estimated using an atom/fragment contribution method (Software Pallas 3.7.1.1 pKa prediction module pKalc 5.1).
The result of the calculation gave no pKa for the test substance.
No pH correction was therefore necessary but a buffer was used to determine the partition coefficient at a specific pH-value.

Radiolabelling:

no

Study design

Test temperature:

35 °C

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Finnigan Surveyor
- Type: HPLC
- analytical column: LiChrospher 100 CN 5 µm 150*3 mm; Col. No. Q31021; ARC Seibersdorf
- Detection system: DAD (UV 210 nm)

MOBILE PHASES
- Type: 60 % methanol (Chromasolv, Sigma-Aldrich, Lot. No. SZBA021S), 40 % buffer* pH 6.5 in water
*buffer pH 6.5: 10 mMol/L potassiumdihydrogencitrate in water adjusted with sodium hydroxide to pH 6.5.
- Experiments with additives carried out on separate columns: no
- pH: 6.5
- Solutes for dissolving test and reference substances: mobile phase

DETERMINATION OF DEAD TIME
The dead time t0 was determined by an unretained compound (sodium nitrate; assay 100.3 %; Lot SZB91270; Sigma-Aldrich).

REFERENCE SUBSTANCES
see results

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: see results
- Quantity of reference substances: see results
- Intervals of calibration: on day of analysis

REPETITIONS
- Number of determinations: 2

CALIBRATION GRAPH
According to the guidelines a minimum of six reference points, if possible at least one above and one below the expected value of the test substance should be used.
Freshly prepared solutions of four reference compounds (see Table 1) in the mobile phase were injected individually to identify their peak in this
HPLC-system. Then they were injected simultaneously (before and after the test substance) and the exact retention times were determined in
duplicate. The corresponding capacity factors and logarithms of the capacity factors were calculated and plotted as a function of the log KOC.
A linear regression line was calculated from the data of this graph.
The log KOC values of the reference compounds are described in the guidelines.

SELECTION of pH
According to the guideline two tests should be performed, for ionisable substances with both ionised and non-ionised forms but only in cases where at least 10 % of the test compound will be dissociated within pH 5.5 to 7.5.
The pKa of the test substance was estimated using an atom/fragment contribution method (Software Pallas 3.7.1.1 pKa prediction module pKalc 5.1).
The result of the calculation gave no pKa for the test substance. No pH correction was therefore necessary but a buffer was used to determine the
partition coefficient at a specific pH-value.
The main test was performed at pH 6.5.

Results and discussion

Adsorption coefficient

Type:

log Koc

Value:

9.53

Temp.:

35 °C

Results: HPLC method

Details on results (HPLC method):

Preliminary result
The calculated adsorption coefficients log KOC of "BTAC-245" are 7.9 (MCI) and 7.3 (log Kow).

Main test
Results for reference and test substances see attachment.
The actual pH value of the mobile phase during the test was 6.5.
The temperature during the test was 35 °C.
The calibration curve of the reference substances was: log k' = 0.1482 x log KOC – 0.4052.
The results of the individual determinations of the decadic logarithm of the adsorption coefficient log KOC of "BTAC-245" were 9.51 and 9.55.
The mean adsorption coefficient log KOC of "BTAC-245" is 9.53* at pH 6.5.
The values of log Koc derived from two measurements were within a range of 0.25 log unit.
*The experimentally determined log KOC is outside the range (1.5 to 5.0) for which the method is published in the guideline.
The log KOC was therefore only determined with four reference substances and no further tests were performed.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The actual pH value of the mobile phase during the test was 6.5.
The temperature during the test was 35 °C.
The calibration curve of the reference substances was: log k' = 0.1482 x log KOC – 0.4052.
The results of the individual determinations of the decadic logarithm of the adsorption coefficient log KOC of "BTAC-245" were 9.51 and 9.55.
The mean adsorption coefficient log KOC of "BTAC-245" is 9.53* at pH 6.5.
The values of log Koc derived from two measurements were within a range of 0.25 log unit.
*The experimentally determined log KOC is outside the range (1.5 to 5.0) for which the method is published in the guideline.
The log KOC was therefore only determined with four reference substances and no further tests were performed.

Executive summary:

The objective of the study was to determine the adsorption coefficient K_OCof"BTAC-245"using HPLC.

Methods:

Guidelines	Regulation (EC) No 440/2008, Method C.19, OECD Guideline No. 121 for the testing of chemicals, adopted on 22 January 2001
Calculation:	The log KOCwas estimated using an atom/fragment contribution method (Software KOCWIN^ãv 2.00)
Experimental test:	The adsorption coefficient was estimated at pH 6.5 using the retention times of the test substance and of four reference substances. The dead time was determined using sodium nitrate.
Dissociation constant pKa of the test substance	Calculation by the software PALLAS^ãpKa Prediction Module 5.1, version 3.7.1.1.
Selection of pH	According to the guideline, two tests should be performed for ionisable substances with both ionised and non-ionised forms but only in cases where at least 10 % of the test compound will be dissociated within pH 5.5 to 7.5. The result of the calculation gave no pKa for the test substance. No pH correction was therefore necessary but a buffer was used to determine the partition coefficient at a specific pH-value..

 

Results:

Calculation of the pKa's of the test substance	pKa's:         none
Calculation of the adsorption coefficient log KOCfor comparison	log KOC        7.9 (MCI) and                        7.3 (log Kow)
Result of the experimental test at pH 6.5	log KOC         9.5*   at 35 °C

*The experimentally determined log K_OCis outside the range (1.5 to 5.0) for which the method is published in the guideline.