spirodiclofen (ISO);3-(2,4-dichlorophenyl)-2-oxo-1-oxaspiro[4.5]dec-3-en-4-yl 2,2-dimethylbutyrate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

In-life initiated/completed: 06-March-1997 to 03-July-1997

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Study conducted to OECD-Guidelines No. 107 under GLP and in a trusted laboratory.

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Principles of method if other than guideline:

The test vessels containing buffer solution and n-octanol were placed in a water-bath controlled
thermostatically at 20 °C and stirred magnetically for 1 hr. The equilibrated mixture containing of both phases were centrifuged for 60 mins. in glass centrifuge tubes at 4000 rpm at the test temperature of 20 °C using a thermostatically controlled centrifuge (model J2-21M with a rotor model JA14, Beckman (USA). 0.1 mL of the upper octanol layer was pipetted into a 25 or 50 mL measuring flask, respectively and filled up to volume with the eluent of the HPLC method.
After the remainder of the octanol phase was completely removed by means of an 1/16" teflon tube and by applying reduced pressure a portion from the aqueous phase was transferred into a flask with known weight. The water amount was reweight and added with 20 % of acetonitrile. To make sure that the whole amount of test substance was transferred out of the pipette, it was rinsed with the water/acetonitrile mixture.

GLP compliance:

yes

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

5.83

Temp.:

20 °C

pH:

4

Details on results:

From the concentrations measured considering the dilution factor of the octanol and water phases the partition coefficients as the ratio of the concentrations found for octanol and for water was calculated for each run. All results were included to calculate common mean and relative standard deviation given at the bottom of the table below. Furthermore, the quantities of the test substance recovered by the analytical measurements were determined from the concentrations and the phase volumes. The results presented also in the Table 1 show that the recoveries are in accordance with the quantities used.

Table 1 Summary of results

Run No.	Quantity used [mg]	Volume of octanol [mL]	Volume of water [mL]	Concentration in octanol of Spirodiclofen [ mg/L ]	Concentration in water of Spirodiclofen [ Mg/L]	Quantity recovered of Spirodiclofen [ mg ] [ % ]		Partition Coefficient
No.1	209.6	50	50	4079	6.6055	203.9	97	617507
No.2	213.6	50	50	4134	6.6786	206.7	97	619056
No.3	418.7	50	50	8036	9.0045	401.8	96	892404
No.4	411.1	50	50	8000	9.1124	400.0	97	877915
No.5	829.8	50	50	16312	29.329	815.6	98	556161
No.6	809.4	50	50	15717	30.038	785.9	97	523244
				mean (n= 6)				681048
			relative	standard	deviation			24

Notes: amount calculated considering a purity of 99.0% of the test substance

Conclusions:

log Pow = 5.83

Executive summary:

The partition coefficient of Spirodiclofen in octanol-water was determined at pH 4 and 20°C by the shaking method according to OECD-Guidelines No. 107 (corresponding to EEC Guidelines A8) to be 680 000 (log Pow = 5.83). Due to the instability of Spirodiclofen at pH values > 4 the dependence of the partition coefficient on the pH could not be measured.

Key value for chemical safety assessment

Log Kow (Log Pow):

5.83

at the temperature of:

20 °C