6,6-dimethoxy-2,5,5-trimethylhex-2-ene

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 22 to 23 May 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Commercial name: Methyl pamplemousse (as cited in the report)
Chemical name: 1,1-Dimethoxy-2,2,5-trimethyl-4-hexene
Empirical formula: C11H22O2
Molecular weight: 186,29g/mol
CAS No.: 67674-46-8
Expiry date: June 6, 2015
Lot No.: PE00090640

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

3.8

Temp.:

35 °C

pH:

7

Details on results:

Note: Testing was performed at 35°C (column temperature), however the values can be considered to represent the values at an unspecified, probably ambient temperature since no mention is made in the guidelines of the temperature at which the tabulated reference substances log Kow values were determined. Partition coefficients of the test and reference substances are assumed to vary with temperature in the same way.

Table 1: Standards used for determination of log Kow ofMETHYL PAMPLEMOUSSE:

Reference substances	Log Pow	tR1	tR2	tRm	k	log k
Thiourea		2.060	2.060	2.06
Benzyl alcohol	1.1	2.56	2.56	2.56	0.243	-0.615
Benzene	2.1	3.877	3.878	3.88	0.882	-0.054
Toluene	2.7	4.936	4.936	4.94	1.396	0.145
1,4 -dichlorbenzene	3.4	6.195	6.197	6.20	2.008	0.303
Cumene	3.7	7.634	7.636	7.64	2.706	0.432
1,2,4 -Trichlorobenzene	4.2	9.532	9.533	9.53	3.627	0.560

 

Calculation:

 

k = (t_{R /}t₀) - 1 capacity factor,

where,

t_R1, t_R2, t_Rm : retention times (1rst measurement, 2^ndmeasurement, average)

t₀ : « dead time », i.e. retention time of thiourea

 

Linear regression parameters: log Pow = a x log k + b

where;

Correlation coefficient : r= 0.9839

Slope : a = 2.6503

Y-axis intercept : b = 2.5264

 

Results obatined for the METHYL PAMPLEMOUSSE:

tR1	8.142
tR2	8.145
tRm	8.144
k	2.9532
log k	0.4703
log Kow	3.8

Conclusions:

The partition coefficient n-octanol/water of METHYL PAMPLEMOUSSE is:
log Pow = 3.8

Executive summary:

A recent study was conducted to determine the partition coefficient of METHYL PAMPLEMOUSSE by Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline 117 using a buffer solution of the test substance (pH=7).

 

The chromatogram shows one peak at retention times 8.144 minutes, corresponding to a partition coefficient (log value) of 3.8. Therefore, under the test conditions, the partition coefficient n-octanol / water of METHYL PAMPLEMOUSSE was determined as 3.8 at pH 7 and 35 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

3.8

at the temperature of:

35 °C