1-Naphthol, reaction products with formaldehyde

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 January 2018 to 14 April 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:

1995

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Version / remarks:

2016

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7840 (Water Solubility)

Version / remarks:

1998

Deviations:

no

GLP compliance:

yes

Type of method:

flask method

Key result

Water solubility:

0.038 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

5 other: five times the quantity of test material necessary to saturate the desire volume of water estimate from the preliminary test

Incubation duration:

72 h

Temp.:

20 °C

pH:

>= 8.7 - <= 9.3

Key result

Water solubility:

0.106 g/L

Conc. based on:

test mat.

Loading of aqueous phase:

50 other: fifty times the quantity of test material necessary to saturate the desire volume of water estimate from the preliminary test

Incubation duration:

72 h

Temp.:

20 °C

pH:

>= 9.6 - <= 9.9

Details on results:

PRELIMINARY TEST
- The content of test material dissolved in the water sample was 0.056 g/L

MAIN STUDY
Loading rate 1
- The maximum difference of the concentrations determined in the 24, 48 and 72 hour test samples was ≤ 15 %. Based on this, the water solubility of the test material is given as the mean value of the analysed concentrations.
- No test material was detected in the pre-treated sample from the blank water mixture.

Loading rate 2
- The 24-hour measurement was significantly higher than the 48- and 72- hour measurements (maximum difference > 15 %).
- Based on this, the water solubility of the test material was given as the mean value of the 48- and 72-hour measurements.

CONCLUSIONS
- The flask method was applied for the determination of the water solubility of the test material.
- The water solubility of the test material at 20 °C was 0.0381 g/L (loading rate 1) and 0.106 g/L (loading rate 2).
- The pH of the aqueous samples was 8.7 – 9.9.

Table 1: Water Solubility of the Test Material at Loading Rate 1

Stirring time [hours]	Analysed concentration [g/L]	Mean  [g/L]	Maximum difference [%]	pH
24	0.0379	0.0381	13	8.9
48	0.0358			9.3
72	0.0407			8.7

Table 2: Water Solubility of the Test Material at Loading Rate 2

Stirring time [hours]	Analysed concentration [g/L]	Mean  [g/L]	Maximum difference [%]	pH
24	0.146	0.106	7.0	9.9
48	0.107			9.8
72	0.105			9.6

Conclusions:

Under the conditions of this study the water solubility of the test material at 20 °C was 0.0381 g/L (loading rate 1) and 0.106 g/L (loading rate 2).

Executive summary:

The water solubility of the test material was investigated in accordance with the standardised guidelines OECD 105, EU Method A.6. and OPPTS 830.7840, under GLP conditions.

The flask method was applied for the determination of the water solubility of the test material and quantitative analysis was performed using an ultra performance liquid chromatographic method with spectrophotometric detection (UPLC-UV).

In the preliminary test the content of test material dissolved in the water sample was 0.056 g/L, as the water solubility of the test material was ≥ 10^-2 g/L the flask method was chosen for the main study. The main study was performed at loading rate 1 (five times the quantity of test materialnecessary to saturate the desire volume of water estimate from the preliminary test) and loading rate 2 (fifty times the quantity of test material necessary to saturate the desire volume of water estimate from the preliminary test). Three aliquots between 0.0138 and 0.0164 g of the test material and three aliquots between 0.1397 and 0.1434 g of the test material were weighed into glass vessels. To each vessel, 50 mL double distilled water was added. The vessels were placed on a magnetic stirring device at 20.0 ± 0.2 °C where the content of each vessel was stirred at 300 rpm for 24, 48 or 72 hours. As the blank, 50 mL double distilled water was stirred for 72 hours. After the stirring period, the water phases were four-times centrifuged at 16 421 g and 20 °C for 5 minutes.

The pH of the aqueous samples was 8.7 – 9.9.

Under the conditions of this study the water solubility of the test material at 20 °C was 0.0381 g/L (loading rate 1) and 0.106 g/L (loading rate 2).

Description of key information

Under the conditions of this study the water solubility of the test material at 20 °C was 0.0381 g/L (loading rate 1) and 0.106 g/L (loading rate 2).

Additional information

The water solubility of the test material was investigated in accordance with the standardised guidelines OECD 105, EU Method A.6. and OPPTS 830.7840, under GLP conditions. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The flask method was applied for the determination of the water solubility of the test material and quantitative analysis was performed using an ultra performance liquid chromatographic method with spectrophotometric detection (UPLC-UV).

In the preliminary test the content of test material dissolved in the water sample was 0.056 g/L, as the water solubility of the test material was ≥ 10^-2 g/L the flask method was chosen for the main study. The main study was performed at loading rate 1 (five times the quantity of test materialnecessary to saturate the desire volume of water estimate from the preliminary test) and loading rate 2 (fifty times the quantity of test material necessary to saturate the desire volume of water estimate from the preliminary test). Three aliquots between 0.0138 and 0.0164 g of the test material and three aliquots between 0.1397 and 0.1434 g of the test material were weighed into glass vessels. To each vessel, 50 mL double distilled water was added. The vessels were placed on a magnetic stirring device at 20.0 ± 0.2 °C where the content of each vessel was stirred at 300 rpm for 24, 48 or 72 hours. As the blank, 50 mL double distilled water was stirred for 72 hours. After the stirring period, the water phases were four-times centrifuged at 16 421 g and 20 °C for 5 minutes.

The pH of the aqueous samples was 8.7 – 9.9.

Under the conditions of this study the water solubility of the test material at 20 °C was 0.0381 g/L (loading rate 1) and 0.106 g/L (loading rate 2).