3,4,5-trihydroxybenzoic acid

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline followed

Principles of method if other than guideline:

no information but peer-reviewed handbooks

GLP compliance:

not specified

Type of method:

other: no information but peer-reviewed handbooks

Key result

Water solubility:

11.9 g/L

Temp.:

20 °C

Remarks on result:

other: pH not provided; source = Yalkowsky

Key result

Water solubility:

11.4 g/L

Remarks on result:

other: expressed as "1 g dissolves in 87 mL water"; temperature and pH not indicated ; source = Budavari

Conclusions:

The water solubility of the test item ranges 11.4-11.9 g/L at 20°C according to peer-reviewed litterature.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

no guideline followed

Principles of method if other than guideline:

WS has been measured at different temperature using analytical method (UV/VIS spect.)

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

Gallic acid monohydrate, with a purity of 99.5 mass %, was purchased from Scharlau (Barcelona, Spain). Gallic acid was dried to constant weight in an air oven at 383 K before use.

Water solubility:

1.516 other: % w/w

Temp.:

24.85 °C

Remarks on result:

other: pH not specified

Temperature (K)	298.2	303.2	308.2	313.2	318.2	323.2	328.2	333.2
Temperature (°c)	24.85	29.85	34.85	39.85	44.85	49.85	54.85	59.85
Experimental WS (% w/w)	1.516	1.615	2.367	2.540	3.429	3.820	4.787	7.378
Calculated WS (%w/w)	1.505	1.760	2.117	2.580	3.210	4.071	5.230	6.831

Conclusions:

The water solubility of gallic acid has been measured using UV/vis spectrophotometer as 1.516%w/w at 24.85°C.

Executive summary:

The water solubility of gallic acid has been measured using UV/vis spectrophotometer as 1.516%w/w at 24.85°C.

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Principles of method if other than guideline:

WS has been measured at different temperature using analytical method (UV spect.)

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

Gallic acid (≥98% purity; CAS No. 149-91-7) was obtained from Sigma-Aldrich.

Water solubility:

14.7 g/L

Temp.:

24.85 °C

Remarks on result:

other: pH not specified

Temperature (K)	323	313	303	298	288
Temperature (°c)	49.85	39.85	29.85	24.85	14.85
Experimental WS (g/L)	38.9	26.4 (& 22.5*)	18.6	14.7	9.1
pH	2.56	2.63	2.67	2.69	2.72

* measured by gravimetry

Conclusions:

The water solubility of gallic acid has been measured by UV spectrophotometry and calculated as 14.7 g/L at 24.85°C.

Executive summary:

The water solubility of gallic acid has been measured by UV spectrophotometry and calculated as 14.7 g/L at 24.85°C.

Reference 4

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Principles of method if other than guideline:

WS has been measured at different temperature using analytical method (HPLC)

GLP compliance:

no

Type of method:

flask method

Specific details on test material used for the study:

3,4,5-trihydroxybenzoic acid (gallic acid hydrate; CAS# 149-91-7; Lot# CBEJB; mass fraction purity g 0.97 powder) was obtained from VWR (Batavia, IL, USA).

Water solubility:

13 g/L

Temp.:

24.85 °C

Remarks on result:

other: pH not specified

Temperature (K)	298.75	314.65	334.95	355.25	375.35	395.65	415.85
Temperature (°c)	24.85	40.85	60.85	81.85	99.85	121.85	114.85
Experimental WS (g/L)	13.0	25.0	83.7	211	532	1000	2870

Conclusions:

The water solubility of gallic acid has been measured by HPLC as 13.0 g/L at 24.85°C.

Executive summary:

The water solubility of gallic acid has been measured by HPLC as 13.0 g/L at 24.85°C.

Description of key information

The weight of evidence approach applies to the publications of Daneshfar A. et al (2008), Motta F.L. et al. (2008) and Srinivas et al. (2010) and in handbooks of Yalkowsky & Dannenfelser (1992) and Budavari (1996).

 

The weight of evidence approach is justified as determined from more than one piece of information (independent sources). We claim the reliability, relevance, adequacy and quality of the weight of evidence:

-       Reliability: Klimisch score of 2 is assigned to the studies

-       Relevance:

o  Relevance of test material: substance purity ranges from ≥97% (Srinivas et al.,2010), ≥98% (Mota et al., 2008) to 99.5% (dried gallic acid monohydrate) without affecting the reproducibility of the endpoint value.

o  Relevance of test method and conditions: the tested methods are described in the 3 publications.

o  Relevance of the endpoint: the values obtained from independent sources show a good reproducibility.

-       Adequacy: the endpoints, whereas obtained from not internationally approved test guideline, with different sources and purity of test item lead to a clear trend: solubility of 13.0-15.16 g/L at 24.85°C and 11.4 -11.9 g/L at 20°C.

-       Quantity: Five pieces of information are considered.

Key value for chemical safety assessment

Water solubility:

11.4 g/L

at the temperature of:

20 °C