Registration Dossier

Administrative data

Endpoint:
water solubility
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24th July 2017 to the 20th November 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method A.6 (Water Solubility)
Qualifier:
according to
Guideline:
OECD Guideline 105 (Water Solubility)
GLP compliance:
yes (incl. certificate)
Type of method:
column elution method

Test material

Reference
Name:
Unnamed
Test material form:
solid: crystalline
Details on test material:
Expiry date:01 February 2021
Storage conditions: Room temperature in the dark
Batch 21-16131
Specific details on test material used for the study:
Identification:
2,5-diphenyloxazole
Appearance/Physical state:
White crystalline powder
Batch:
21-16131
Purity:
99.9%
Expiry date:
01 February 2021
Storage conditions:
Room temperature, in the dark

Results and discussion

Water solubility
Key result
Water solubility:
>= 0.001 - <= 0.001 g/L
Conc. based on:
test mat. (dissolved fraction)
Incubation duration:
ca. 3 h
Temp.:
20 °C
pH:
ca. 5.7

Any other information on results incl. tables

The concentration of test item in the sample solutions was determined by high performance

liquid chromatography (HPLC).

Samples

An aliquot of each sample solution was diluted by a factor of 2 using methanol.

Standards

Duplicate standard solutions of test item were prepared in methanol: purified water (1:1 v/v)

at a nominal concentration of 0.25 mg/L.

Matrix blank

Methanol: purified water (1:1 v/v).

Analysis

The standard and sample solutions were analyzed by HPLC using the following conditions:

HPLC System : Agilent Technologies 1200, incorporating workstation

and autosampler

Detector type : variable wavelength (VW)

Column : Phenomenex Kinetix EVO C18 100Å (150 x 4.6 mm id)

Column temperature : 30 °C

Mobile phase : Methanol: purified water (75:25 v/v)

Flow-rate : 1.0 mL/min

Injection volume : 100 μL

VW detector wavelength : 303 nm

Retention time : ~ 4.0 mins

Applicant's summary and conclusion

Conclusions:
The substance, 2,5-diphenyloxazole, water solubility was studied in accordance with EC Method A.6 and OECD Method 109 via a GLP-certified laboratory. The study used the column elution method with HPLC analysis and determined that the substance water solubility was 0.000625 g/L at 20.0 ± 0.5 °C.
Executive summary:

The substance, 2,5-diphenyloxazole, water solubility was studied in accordance with EC Method A.6 and OECD Method 109 via a GLP-certified laboratory. The column elution apparatus was set up in duplicate (Systems A and B). Each system consisted of a glass micro-column fitted with a plug of glass wool, connected to a recirculating pump and a reservoir holding approximately 500 mL of purified water. Temperature was thermostatically controlled via circulating water from a water bath fitted with a cooling coil and maintained at 20.0 ± 0.5 °C. An aliquot (0.1163 g) of test item was dispersed in 20 mL of dichloromethane. Glass beads (approximately 1.0 g) were added and the solvent removed using a rotary evaporator (35 °C).

The systems were flushed with purified water for approximately 3 hours which was then discarded. The reservoirs were re-filled with fresh purified water and approximately half the coated glass beads loaded into each micro-column. After allowing the coated beads to soak for at least 2 hours, the water in the column was run to waste. The recirculating pumps were switched on and approximately 30 mL of column eluate collected to determine the flow rate.

The mean peak area and concentration of each standard solution were plotted on a calibration curve and the sample concentration interpolated from the curve. The values were then corrected for the dilution factor. The study used the column elution method with HPLC analysis and determined that the substance water solubility was 0.000625 g/L at 20.0 ± 0.5 °C.