cyclohexadecanone

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 to 25 August 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Key result

Water solubility:

0.13 mg/L

Temp.:

20 °C

pH:

>= 7.4 - <= 7.5

Results and Discussion

For the higher flow rate of 0.69 mL/min, the equilibrium concentration was achieved after 49 hours with seven consecutive samplings showing a relative standard deviation of 5.4% and a deviation between highest and lowest measured concentration of 13.4%. For the lower flow rate of 0.35 mL/min, the equilibrium concentration was achieved after 28 hours with five consecutive samplings showing a relative standard deviation of 13.5% and a deviation between highest and lowest measured concentration of 26.5%. Detailed results are reported in the table below.

 

Results for Determination of Water Solubility

Experiment Number	Flow Rate	Sample Number	pH (a)	Sampling Time	Measured Concentration of Test Item in Sample x	Water Solubility   Mean Value ± Std. Dev.	Rel. Std. Dev.
	[mL/h]			[hours]	[mg/L]	[mg/L]	[%]
1	0.69	16	6-7	49	0.132	0.143 ± 0.008	5.4
		17	6-7	50	0.136
		18	6-7	51	0.149
		19	6-7	52	0.151
		20	6-7	53	0.152
		21	6-7	54	0.141
		22	6-7	55	0.143
2	0.35	9	6-7	28	0.115	0.114 ± 0.015	13.5
		10	6-7	30	0.105
		11	6-7	32	0.103
		12	6-7	34	0.141
		13	6-7	36	0.108
Overall Mean:						0.13

Remark:

The Table only shows the data obtained during the equilibrium phase (RSD of five samples < 30 %).

(a) The pH value in the individual samples was measured with special indicator strips. After the end of the experiment the pH of the bulk solution was measured using an electrode: the values were 7.4 for experiment 1 and 7.5 for experiment 2.

  

The deviation between the mean values obtained for the two different flow rates was 20.2 %.

 

According to the test guideline five consecutive samples should not differ in concentration by more than 30% and the mean values obtained from two tests with different flows should not differ by more than 30%. These criteria were fulfilled and therefore, the study is valid.

 

The R² fit of the calibration curve used was 0.99. This reflects the linearity of the analytical system within the calibration range of 0.0316 - 0.264 mg test item /L.

The calibration was verified by a 2nd weighing of the test item and dilution of this stock solution into the calibration curve at levels of 0.0489, 0.0974 and 0.193mg/L. Analysis of these solutions and evaluation against the calibration curve yielded recoveries of 90 %, 113 % and 109 % compared to the nominal values. These data show the correct preparation of the calibration solutions.

The stability of the analytical system during the measurement series was confirmed by repeated injection of the calibration solutions.

An analysed analytical blank (solvent mixture) did not affect the chromatogram at the retention time of the test item.

Conclusions:

A water solubility value of 0.13 mg/L (at 20 °C, pH 7.4 - 7.5) was determined for the test substance according to OECD guideline 105.

Description of key information

Water solubility: 0.13 mg/L at 20 °C, pH 7.4 -7.5 (OECD 105, column elution method)

Key value for chemical safety assessment

Water solubility:

0.13 mg/L

at the temperature of:

20 °C