2-propen-1-amine, N-2-propen-1-yl-, hydrochloride

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

other: Expert Assessment

Adequacy of study:

key study

Study period:

2021

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: An assessment was performed based on the preliminary examination of the substance

Principles of method if other than guideline:

The assessment is based on a preliminary examination of the substance.

GLP compliance:

no

Type of method:

other: Expert Assessment

Specific details on test material used for the study:

The test substance was supplied as a 67% solution in water and as such the substance is water soluble. To perform preliminary water solubility studies, a sample of the aqueous solution of 2-propen-1-amine, N-2-propen-1-yl, hydrochloride (1:1) was concentrated. This resulted in a yellow crystalline solid which was very hygroscopic in nature. Prior to the preliminary studies, the solid was dried in an oven at 80 oC. The water content prior to testing was found to be 0.3% w/w and the sample was considered suitably dry.

Key result

Water solubility:

> 10 g/L

Conc. based on:

test mat.

Temp.:

20 °C

pH:

7

Details on results:

Prior to the water solubility studies, a preliminary study was conducted in order to ascertain a suitable method by which the water solubility of the sample could be determined; to estimate the mass of sample required to saturate a desired volume of water and to determine the volume of water required for the formal solubility test. The test was conducted in accordance with OECD Test Guideline 105.

Based on the preliminary studies, the estimated water solubility is >10 g L-1. Consequently, it is not thought possible to prepare a saturated solution of the substance at about five times the preliminary estimation value as this would probably form a paste that would not be possible to filter or centrifuge. However, two attempts were made to prepare a saturated solution as detailed in Appendix 1 (Attempt one contained 5 g in 1250 µL and attempt 2 contained 5 g in 1500 µL). Both saturated solutions were filtered through a syringe filter and a clear brown solution was obtained. This solution was then analysed using high performance liquid chromatography with an ultraviolet detector (HPLC-UV).

The HPLC-UV analysis of the sample showed two peaks in the chromatogram (see attached report). Initially, the two peaks were thought to be a mixture of the hydrochloride salt and the free base of the substance. To ascertain whether this was happening, the pH of the saturated solution was adjusted to 12.5 to give the free base of the substance. The pH was then further adjusted to 2.2 to convert all the species to the salt form. However, when this solution was analysed, it gave similar results to the initial analysis.

As the test item had originally been an aqueous solution and has had the water removed for the purposes of the water solubility testing, it was thought that the test item may have been altered during the drying process. However, a HPLC-UV analysis of the aqueous solution provided similar results to the dried solid.

Further analysis was conducted by HPLC-MS to determine the identity of both peaks observed in the HPLC chromatogram. The second peak had a mass spectrum consistent with that of 2-propen-1-amine, N-2-propen-1-yl, hydrochloride (1:1), however, the mass spectra of the 1st peak was extremely complex and an identity could not be established. . Whilst the identity of the first peak could not be established, this was not considered relevant to the overall composition of the substance. As part of the registration a substance characterisation was performed on the substance, which included an NMR spectrum of the aqueous solution. The spectrum showed only signals consistent with the diallylamine, any impurities are below the detection limits of the NMR and are not considered significant. Furthermore, Ion Chromatography (IC) analysis was also performed detected 18.12% of chloride ions, which is equivalent to 68.31% diallylamine hydrochloride salt. Therefore, the unknown peak does not alter the composition of the substance and is assumed to be a complication with the HPLC-UV method. As no reference standards are available for 2-propen-1-amine, N-2-propeny-1-yl hydrochloride (1:1), the response factor for the HPLC-UV could not be established. Therefore, determination of the water solubility of 2-propen-1-amine, N-2-propen-1-yl, hydrochloride (1:1) was not feasible

As the water solubility could not be determined by HPLC analysis, the preliminary results have been used to estimate the water solubility of 2-propen-1-amine, N-2-propen-1-yl, hydrochloride (1:1). The preliminary results showed that the estimated water solubility is >10 g L-1.

Conclusions:

An assessment was performed to determine the water solubility of the test substance, 2-propen-1-amine, N-2-propen-1-yl-, hydrochloride based on a preliminary examination if the substance. It was concluded that 2-propen-1-amine, N-2-propen-1-yl, hydrochloride (1:1) will have a water solubility of >10 g/L.

Executive summary:

The assessment is based on a preliminary examination of the substance.

Prior to the water solubility studies, a preliminary study was conducted in order to ascertain a suitable method by which the water solubility of the sample could be determined; to estimate the mass of sample required to saturate a desired volume of water and to determine the volume of water required for the formal solubility test. The test was conducted in accordance with OECD Test Guideline 105.

Based on the preliminary studies, the estimated water solubility is >10 g L-1.

Description of key information

The assessment is based on a preliminary examination of the substance.

Prior to the water solubility studies, a preliminary study was conducted in order to ascertain a suitable method by which the water solubility of the sample could be determined; to estimate the mass of sample required to saturate a desired volume of water and to determine the volume of water required for the formal solubility test. The test was conducted in accordance with OECD Test Guideline 105.

Based on the preliminary studies, the estimated water solubility is >10 g L-1.

Key value for chemical safety assessment

Water solubility:

10 g/L

at the temperature of:

20 °C