5-bromo-1,3-dichloro-2-fluorobenzene

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:

2019-03-17 until 2019-05-13

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))

Version / remarks:

January 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
- Type: Thermo Scientific Dionex HPLC equipped with Diode Array Detector Ultimate 3000.
- Type, material and dimension of analytical (guard) column: Zorbax CN, 250 x 4.6 mm, 5 µm, Agilent Technologies
- Detection system: UV; Dionex DAD Ultimate 3000 MAD

MOBILE PHASES
- Type: methanol : water (55:45, v:v), isocratic
- Experiments with additives carried out on separate columns: no
- Solutes for dissolving test and reference substances: methanol:water (50:50 v:v)

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column (formamide)

REFERENCE SUBSTANCES
- Identity: diclofop-methyl, fenthion, linuron, phenanthren, acetanilide, endosulfan-diol

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 2.50 µg (50 μL of a 49.9 µg/mL solution)
- Quantity of reference substances: 2.25 µg to 2.5 μg (50 μL of a 45 µg/mL to 50 μg/mL solution)
- Intervals of calibration: Reference compounds were injected separately. Two injections (50 µL) of each reference compound were performed employing the conditions described above. All references were injected in a first serial, then the test item was injected and then all references again were injected in a second serial. The test item solution was injected once between the two serials of the references.

REPETITIONS
- Number of determinations: two injections per reference compounds (one injection before and one injection after the test item injection) and one injection of the test item.

EVALUATION
- Calculation of capacity factors k': k´and log k´were calculated using the measured retention times
- Determination of the log Koc value:orrelation graph was produced by plotting the log k’ value v
ersus the log KOC value for each reference compound; literature log Koc values were obtained from
OECD Guideline 121. A log Koc value for the test item was then extrapolated from the correlation
graph.

Key result

Type:

Koc

Value:

1 660

Details on results (HPLC method):

One significant peak was observed for CA5528C eluting at retention time 14.34 minutes. The retention time of CA5528C was within the calibration range of retention times of the 6 reference substances chosen in this study and listed in the OECD guideline 121. Hence, the log KOC was calculated using the equation of the regression line obtained, resulting in a value of 3.22. The corresponding KOC for CA5528C was then calculated to be 1660.

Capacity factor (k´) and adsorption coefficient (Koc) values for CA5351 of HPLC-runs using

methanol:water (55:45; v:v) as mobile phase.

ccompound	retention time injection 1 UV-detector (min)	retention time injection 2 UV-detector (min)	mean retention time** UV-detector (min)	capacity factor k´	log k´	log Koc
Formamide	4.29	4.29	4.29	0.000	unretained	unretained
Acetanilide	5.92	5.92	5.92	0.380	-0.420	1.25*
Linuron	11.66	11.67	11.66	1.717	0.235	2.59*
Endosulfan-diol	12.82	12.82	12.82	1.987	0.298	3.02*
Fenthion	19.69	19.70	19.70	3.588	0.555	3.31*
Phenanthren	21.81	21.82	21.81	4.082	0.611	4.09*
Diclofop-methyl	22.76	22.77	22.76	4.303	0.634	4.20*
CA5528C	14.34			2.342	0.370	3.22#

* Reference Compound Literature values taken from OECD Guideline 121

** Mean retention time of two injections per sample

# Calculated from equation of calibration plot

Validity criteria fulfilled:

yes

Conclusions:

The method for the estimation of the adsorption coefficient by HPLC was suitable for the substance. The determined values were:
log Koc = 3.22
Koc = 1660 mL/g
The substance can be classified as having a “low” potential mobility.

Executive summary:

Study Design

The adsorption coefficient of the substance was estimated according to the OECD TG 121, Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC), January 2001.

The test substance was chromatographed on a cyanopropyl solid phase HPLC column concurrently with 6 reference compounds of known adsorption coefficient values.

Following chromatography using a mobile phase of methanol:water (55:45, v:v), a correlation graph was produced by plotting the log k’ value versus the log Koc value for each compound. Literature log Koc values were obtained from the OECD TG 121. Log Koc values for the test items were then extrapolated from the correlation graph. A good correlation between log k’ and log Koc was observed for the reference compounds tested with a coefficient of determination r²of 0.9356.

One significant peak was observed for the substance eluting at retention time 14.34 minutes. 

The retention time of the substance was within the calibration range of the retention times of the 6 reference substances chosen in this study and listed in the OECD TG 121. Hence, the log Koc could be calculated using the equation for the regression line obtained, resulting in a value of 3.22. The corresponding Koc for the substance was then calculated to be 1660 mL/g.

Description of key information

Koc = 1660 L/kg (determined by HPLC under GLP and according to OECD TG 121)

Key value for chemical safety assessment

Koc at 20 °C:

1 660