Phosphoric acid, butyl ester, sodium salt

pH

Administrative data

Endpoint:

pH

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-12-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-12-15

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Qualifier:

according to guideline

Guideline:

other: ISO 304:1985: Surface active agents -- Determination of surface tension by drawing up liquid films

Principles of method if other than guideline:

The surface tension of a solution of surfactant generally decreases with increasing concentration until the CMC is achieved. At higher concentration, the surface tension remains essentially unchanged. In a graph of the surface tension as a function of concentration, points form normally two straight lines with different slopes. The CMC is given by the intersection of the two straight lines.

GLP compliance:

no

Type of method:

other: critical micelle concentration (CMC)

Key result

Water solubility:

0.061 g/L

Conc. based on:

test mat.

Incubation duration:

15 min

Temp.:

20 °C

pH:

6.73

Remarks on result:

other: Critical micelle concentration

Details on results:

Three independent measurements were performed. From each experiment the curves for the two straight lines were determined. The individual results differ by 15.8 % and thus were regarded as acceptable.

Experiment 1

Concentration (g/L)	0.00187	0.00367	0.00487	0.00857	0.01543	0.22120	0.49600	1.08900	2.02600
Surfacetension (mN/m)	70.0	63.2	56.8	48.0	48.2	31.4	32.1	32.4	31.9

 

Experiment 2

Concentration (g/L)	0.00092	0.00238	0.00352	0.00711	0.0087	0.03045	0.23343	0.5220	0.5950	1.9310
Surfacetension (mN/m)	71.0	58.0	53.1	52.9	44.0	41.9	31.6	31.8	32.0	31.9

 

Experiment 3

Concentration (g/L)	0.00093	0.00205	0.00378	0.00525	0.00984	0.01596	0.07024	0.09314	0.469	1.101	2.051
Surface tension (mN/m)	70.2	66.5	61.1	52.8	50.5	44.4	34.3	31.1	32.2	31.8	32.1

 

  curves of the surface tension as a function of the concentration of the test item in water

Curve	Straight line 1	Straight line 2	CMC (g/L)	Average	Standard deviation
1	y = -11.37 ln(x) -2.2107	y = 0.2626 ln(x) +32.043	0.053	0.061	0.0097
2	y = -8.185 ln(x) + 10.006	y = 0.1328 ln(x) +31.89	0.072
3	y = -9.433 ln(x) + 6.086	y = 0.292 ln(x) + 32.01	0.059

 

Conclusions:

The critical micelle concentration was determined to be 0.061 ± 0.0097 g/L at 20 °C.

Executive summary:

A study was conducted to determine critical micelle concentration (CMC) of the test item in water. The substance is a surfactant and thus the determination of the water solubility was technically not feasible. Upon reaching CMC, any further addition of test item will just increase the number of micelles. Below the CMC concentration the test item only individual surfactant molecules are present. Using the plate method to determine the surface tension, three individual experiments were performed to determined the surface tension as a function of the test item concentration. The functions of the two curves above and below the CMC were determined and the CMC was determined by the intersection of the two straight lines. The CMC was determined to be 0.061 ± 0.0097 g/L at 20 °C in water.

Materials and methods

Test guideline

Qualifier:

no guideline followed

GLP compliance:

no

Reagents

Reagent:

water

Results and discussion

pH value

Key result

pH value:

6.73

Temp.:

20 °C

Concentration:

1 g/L

Applicant's summary and conclusion

Conclusions:

The pH vale of the test item was determined to be 6.73 at 20°C and 1 g/L.

Executive summary:

A study was conducted to determine the pH value of the test item. Using a pH-Meter the pH-value of the test item was determined to be 6.73 at 20 °C and 1 g/L.