(3-methoxy-2-methylpropyl)benzene

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2015-02-02 to 2015-02-06

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study was conducted according to OECD/EC guideline, and under GLP. No deviation was reported. Test substance is adequately specified with purity. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes (incl. QA statement)

Remarks:

inspected on June 3 to 5, 2013 / signed on November 5, 2013

Type of method:

flask method

Key result

Water solubility:

195 mg/L

Loading of aqueous phase:

0.85 g/L

Temp.:

20 °C

pH:

6.4

Remarks on result:

other: for double distilled water

Water solubility:

193 mg/L

Loading of aqueous phase:

0.85 g/L

Temp.:

20 °C

pH:

7.8

Remarks on result:

other: for daphnia M4 medium

Details on results:

Method Validation
Linearity: LOD = 0.15 mg/L
System quantification limit = 0.5 mg/L
range of nominal 0.5 - 100 mg/L (n = 9) with coefficient of determination for the linear calibration curve (r2) of 0.999932.

Limit of Quantification
Nominal LOQ = 2 mg/L

Accuracy and Precision
Double distilled water: Mean recovery rates were 92 % for the 1 x LOQ and 99 % for the 10 x LOQ (RSD ≤ 1.5 %)
Daphnia M4 medium: Mean recovery rates were 93 % for the 1 x LOQ and 98 % for the 10 x LOQ (RSD ≤ 2.5 %)

Specificity
Analyses were performed with DAD (diode array detection) as selective detector. Spectra of sample peaks were compared automatically by the software against spectra obtained from standard peaks. For all samples, a maximum spectra match angle of 6.301 was observed, the maximum observed match threshold was 16.555.
The spectral match angle was lower than the match threshold for all samples, confirming the identity of the analyte peaks. For the control samples, no significant signal could be detected, showing that blank values were lower than 30 % of the LOQ.

Preliminary Test (non GLP): The determined solubility in double distilled water was in the range of 0.136 - 0.17 g/L. For the application dose for the definitive study, 0.85 g/L, as approx. the fivefold of the solubility result, was used.

Table 4.8/1: Water Solubility Results at 20 °C for test item in Double Distilled Water 

Preincubation time	Replicate No.	Test item (mg/L)
		Concentration^1	Mean
24 h	1	185	190
	2	196
48 h	1	195	194
	2	193
72 h	1	197	199
	2	200
Mean (24 - 72 h)			195
Deviation [%] (24 - 72 h)			4.3

 

¹Mean value of double injections, dilution factor of 4 taken into account

 

Table 4.8/2: Water Solubility Results at 20 °C for test item in Daphnia M4 Medium

 

Preincubation time	Replicate No.	Test item (mg/L)
		Concentration^1	Mean
24 h	1	198	195
	2	191
48 h	1	192	194
	2	197
72 h	1	196	191
	2	187
Mean (24 - 72 h)			193
Deviation [%] (24 - 72 h)			2.0

 

¹Mean value of double injections, dilution factor of 4 taken into account

 

Equilibrium was considered achieved at first sampling interval (24 h) in both media.

The solubilities determined for the two test media did not differ significantly.

 

Validity Criteria

The validity criteria were fulfilled:

The concentration measured at each sampling time did not differ for more than 15 %.

Temperatures were kept constant within ± 0.5 °C.

Conclusions:

Interpretation of results (migrated information): moderately soluble (100-1000 mg/L)

Executive summary:

The water solubility of the test substance was measured under GLP according OECD 105 guideline and EU A6 guideline, flask method.

The solubility of the test item was determined using the flask method at 20 ± 0.5 °C with preincubation at 30 ± 0.5 °C. Three measurements were performed at 24, 48 and 72 h, with duplicate analysis. Equilibrium was considered achieved at first sampling interval (24 h) for both media (double distilled water and Daphnia M4 medium).

 

The analytical method (UPLC-DAD, external standard) for the determination of the test item was validated and tested with satisfactory results in regard to linearity, accuracy, precision and specificity.

 

The water solubility of the test item was determined to be 195 mg/L (20 ± 0.5 °C, pH 6.4) for double distilled water and 193 mg/L (20 ± 0.5 °C, pH 7.8) for daphnia M4 medium.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From August 18 to 29, 1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

The study was conducted according to OECD/EC/NF guideline, and under GLP. Test substance is adequately specified with purity. Validation applies, with restrictions due to lack of experimental details.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

yes

Qualifier:

according to guideline

Guideline:

other: French standard NF T 20-046

Principles of method if other than guideline:

Not applicable

GLP compliance:

yes

Type of method:

flask method

Water solubility:

0.27 g/L

Temp.:

22 °C

pH:

7

Remarks on result:

other: ± 1 °C

Table 4.8/1: Water solubility – results

	24- hour	48- hour	72- hour
T (°C)	22	22	22
pH	7	7	7
Mass concentration (g/L)	0.28	0.26	0.26

 

Mean value: 0.27 g/L

The repeatability of these tests is 3.5 % (< 15 %).

Conclusions:

Interpretation of results (migrated information): moderately soluble (100-1000 mg/L)

Executive summary:

The water solubility of the test substance was measured under GLP according to OECD 105/EU A6 guidelines, flask method with HPLC-UV analysis. Three measurements were performed at 24, 48 and 72 h. Equilibrium was considered achieved, and the mean value is retained.

The water solubility of the test substance is 0.27 g/L at 22°C (pH 7).

Description of key information

Moderately soluble. Equilibrium after 24h.
 pH of saturated solution: 6.4

Key value for chemical safety assessment

Water solubility:

195 mg/L

at the temperature of:

20 °C

Additional information

Two reliable studies, conducted according to recognized OECD/EC method and under GLP, are available, and provide quite consistent results. Both were performed with the flask method, but experimental details were lacking in the INERIS 1998 study, leading to minor restrictions on accuracy, while the more recent one (Noack 2015), performed with fully validated analytical method, is considered of higher quality. Therefore the Noack result is preferred and retained as key data, rather than the mean value.