N-[2-(4-oxo-4H-3,1-benzoxazin-2-yl)phenyl]naphthalene-2-sulphonamide

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

February 06 to February 08, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

101.7 mg the test item was transferred to 1 L dilution water in a glass bottle containing a magnetic stirrer. The solution was stirred for about 48 hours at room temperature and thereafter was filtered through a 0.22 µm PES filter to remove unsoluble parts of the test item.Samples were taken from fresh and aged test solutions and the control prior to distribution to the test vessels. At the end of the test, samples were taken directly from two representative replicates of the test concentration and control. Analysis of all samples was performed at test end. The water solubility was determined by LC-MS

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate from May 31, 2016

Type of method:

other: LC-MS

Water solubility:

46.11 µg/L

Conc. based on:

test mat. (dissolved fraction)

Loading of aqueous phase:

100 mg/L

Incubation duration:

48 h

Temp.:

18.8 °C

pH:

>= 8.03 - <= 8.57

Details on results:

The measured concentrations at test termination (during 48 h) were within a range of 80 – 120 % of the initial concentrations confirming the stability of the test item throughout the test.

Regression quality
The basic calibration standards covered concentrations from 0.1 µg/L to 10.0 µg/L. As the calculated correlation coefficient (r²) for Lumilux® Yellow CD397 was close to 1 [r² = 0.996397], the applicability of the linear calibration function was accepted.

Method validation
The analytical method for N-[2-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]naphthalene-2-sulphonamide has been successfully validated in accordance with the EU guidance document SANCO/3029/99 rev. 4 (11/07/00) on two fortification levels.

Accuracy (recovery)
The mean recovery of each fortification level and the overall mean recovery value is defined by SANCO/3029/99 rev.4 (11/07/00) (recovery 70 – 110% with an RSD < 20%). The mean recoveries and the overall mean recovery values are in the defined range of SANCO/3029/99 rev.4 (11/07/00). The accuracy of the method can be accepted.

Repeatability (precision)
The mean RSDs of 10.4% and 2.2% for LOQ and 10x LOQ as well as the overall mean RSD of 7.9% prove the repeatability of the analytical method for the analyte in aqueous solution.

Specificity and blanks
The LC-MS system used was capable to determine the analyte N-[2-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]naphthalene-2-sulphonamide in the worked-up injection-solutions without interference of matrix compounds.
The specificity of the method is shown by an example of an UHPLC-MS/MS chromatogram of untreated fortification sample (blank) in methanol / copper-free water (75:25 v:v). Since there were no detectable respective mass transitions at the retention time of the analyte, the method is accepted as specific.

Measured concentration of test item

Nominal concentration		0 h fresh		48 h aged			Geometric mean measured conc.
[mg/L]	[mg TI/L]	[µg/L]	% of nominal	[µg/L]	% of nominal	% of initial	[µg/L]	% of nominal
Control	Control	< LOQ *	-	< LOQ *	-	-	< LOQ *	-
100.0	101.7	45.38	0.05	46.86	0.05	0.05	46.11	0.05

The measured concentration of test item in fresh prepared test solutions at test start was 45.38 µg/L (corresponding to 0.05 % of the nominal concentration). In aged test solution measured concentration of test item was 46.86 µg/L (corresponding to 0.05 % of the nominal concentration). The resulting geometric mean measured concentration of initial and aged test solutions was 46.11 µg/L (0.05 % of nominal)

Conclusions:

N-[2-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]naphthalene-2-sulphonamide has a water solubility of 46.11 µg/L at 18.8 °C.

Description of key information

N-[2-(4-oxo-4H-3,1-benzoxazin-2-yl) phenyl]naphthalene-2-sulphonamide has a water solubility of 46.11 µg/L at 18.8 °C.

Key value for chemical safety assessment

Water solubility:

46.11 µg/L

at the temperature of:

18.8 °C