1,4-dimethoxybenzene

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:

from 19 jun 2006 to 09 jul 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to standardised guidelines and GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

785 mg/L

Temp.:

20 °C

pH:

4.6 - 4.9

The saturation concentration of Paradimethoxybenzene at room temperature was estimated by a simplified flask method in the preliminary test to be about 1 g/l. Therefore, the flask shaking test was performed.

The concentrations were determined after a shaking time of 24 hours, 48 hours and 72 hours, respectively, at30°C. Afterwards the samples were equilibrated for another 24 hours at 20.0°C. As the measured results differed by less than 15 %, the study is considered to be valid. The water solubility of PDMB was calculated as mean value from the results obtained after 48 hours and 72 hours of shaking. The results of the individual measurements of the main test are summarised in Table 1. The tabulated values represent rounded results, which were obtained by calculation using the exact raw data.

Table 1:     Results of the water solubility of Paradimethoxybenzene

 

Sample No.	Shakingtime at30°C	Concentration analysed	Concentration calculated	Water solubility calculated (rounded)
		[mg/l]	[mg/l]	[mg/l]
1	72	33.677	841.91
2		33.488	837.20
3	48	29.183	729.58	785.46
4		29.326	733.14	SD = 62.51
5	24	26.593	664.83
6		24.906	622.65

 

 

The saturation mass concentration is calculated from the bold values

SD = standard deviation

Conclusions:

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

Executive summary:

The determination of the water solubility of Paradimethoxybenzene was performed using the flask shaking method. The concentrations were determined by HPLC measurement after a shaking time of 24 hours, 48 hours and 72 hours, respectively, at 30°C. Afterwards the samples were equilibrated for another 24 hours at 20.0°C. A slight increase in concentration was observed at longer equilibration times. As the measured results differed by less than 15%, the study is considered to be valid. The water solubility of PDMB was calculated as mean value from the results obtained at 48 hours and 72 hours of shaking.

In conclusion, the water solubility of Paradimethoxybenzene at 20°C was determined to be 785 mg/l (standard deviation ± 63 mg/l).

The water solubility was not corrected for the purity of the test item (as given under item 2.1).

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 may 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study conducted according to OECD guideline, but not GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

no

Type of method:

flask method

Water solubility:

708 mg/L

Temp.:

20 °C

pH:

6.8

Details on results:

After 24H equilibration time at 20°C, the substance concentration was found to be 703 mg/L, after 48H, it reached 708 and 712 mg/l at 72H. Since the three samples did not vary by more than 15%, the saturation was estimated to be reached. Mean water solubility = 708 mg/l.

Conclusions:

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

Executive summary:

The water solubility of the test substance Paradimethoxybenzene was determined according to the OECD guideline 105.

In this study (Clariant, 2008), the flask method was used.

The concentrations were determined by UV/VIS measurement after a preincubation time of 5 hours at 30°C and an equilibration time of 24 hours, 48 hours and 72 hours, respectively, at 20°C, with constant stirring.

The water solubility of Paradimethoxybenzene at 20°C and pH 6,8 was determined to be 708 mg/L.

Description of key information

The experimental data (RCC 2007 and Clariant 2008, according to OECD 105, GLP) were chosen as key studies.
RCC study value: 785 mg/L at 20°C
Clariant study value: 708 mg/L at 20°C

Key value for chemical safety assessment

Water solubility:

785 mg/L

at the temperature of:

20 °C

Additional information

Other available data, from Handbook or supplier, were selected as supporting studies and they were in the range from 800 mg/L at 20°C to 1543 mg/L at 25°C and were of reliability 2.