Dioctyl maleate, branched

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 September 2017 to 16 May 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

27 July 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

flask method

Specific details on test material used for the study:

Name: Bernel Ester DCM
Other names: bis(1-methylheptyl) maleate
Physical state: Clear liquid
CAS number: 85566-63-8
EC number 287-673-6
Molecular weight: 340.5 g/mol
Purity: 92.78%
Arrival date: 4 September 2017
Storage conditions: Room temperature (15 to 30°C)

Key result

Water solubility:

ca. 0.015 µg/L

Conc. based on:

test mat.

Incubation duration:

ca. 267 h

Temp.:

20 °C

pH:

> 5.8 - < 6.5

Details on results:

Analytical Procedure for Water Solubility

The validation was run twice. For the first run, Validation 1, the responses for the mid and high recovery levels were above the calibration line, therefore the results were considered unreliable and have not been reported. The mid and high level samples were re-diluted and re-analysed in the Validation 2 batch.
The method was assessed against the criteria detailed in the following sections:

Specificity
Diluting 2 and double-distilled water control samples were free of any components that interfered with the analysis of Bernel Ester DCM. The method was therefore considered specific for the test substance Example chromatograms of Diluent 2 and a double-distilled water control sample are shown in Figure 2 and Figure 3.

Sensitivity
Acceptable mean recovery (70 to 110%), and a %RSD of <20 % was obtained for the analysis of the test substance at 0.005 µg/mL. Therefore, the LOQ was confirmed as 0.005 µg/mL.

The lowest calibration standard was 0.0002 µg/mL and this demonstrated sufficient sensitivity.

Linearity
Response of the LC/MS-ToF system to Bernel Ester DCM was quadratic with a 1/x weighting, over the range 0.0002 to 0.02 μg/mL, with a correlation coefficient >0.99. The linearity of detector response was therefore established.
Example chromatograms of calibration standards are shown in Figure 4 and Figure 5.
A representative calibration plot is shown in Figure 6.

Accuracy (Recovery)
The accuracy of the spiked double–distilled water was within 70 to 110% mean recovery for 0.005, 0.05 and 0.5 µg/mL.

The full results are shown in Table 2.

Example chromatograms for validation samples are shown in Figure 7 to Figure 9.


Precision (Repeatability)
The precision of the spiked double–distilled water had a percent standard deviation (%RSD) of < 20% for 0.005, 0.05 and 0.5 µg/mL.

The full results are shown in Table 2.

Example chromatograms for validation samples are shown in Figure 7 to Figure 9.



Equilibrium was established from the first sample, with good agreement between the three vessels. The last five time point samples, where equilibrium had been reached, were used to calculate the mean water solubility values for each test vessel and the overall water solubility value. he plot of concentration against time appeared to show quite a lot of variability but the %RSD values for each vessel and for the overall solubility value were <30%.

The mean water solubility was 0.015 µg/mL, with a %RSD of 12.02 %.

The full results are shown in Table 7 and a graphical representation is shown in Figure 19.

Representative chromatograms are shown in Figure 20 to Figure 23.

Conclusions:

The water solubility of the test substance was found to be 0.015 µg/l at 20 °C, under the conditions of the test.

Executive summary:

In this guideline (OECD 105) study, conducted with GLP certification, the water solubility of the test substance was found to be 0.015 µg/l at 20 °C.

Description of key information

Study conducted to recognised testing guidelines and with GLP certification.

Key value for chemical safety assessment

Water solubility:

0.015 µg/L

at the temperature of:

20 °C