Diisobutyl hydrogen phosphate

pH

Administrative data

Endpoint:

acidity / alkalinity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

pH

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

GLP compliance:

yes (incl. QA statement)

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Reagent:

buffer solutions

Key result

pH value:

1.5

Temp.:

20 °C

Concentration:

10 g/L

Remarks on result:

other: value after 10 min, no drift.

After 1 minute:              1.4

after 2 minutes:             1.5

after 10 minutes:            1.5

Result:                           1.5

Conclusions:

The pH of a 1% solution of diisobutyl phosphate in demineralized water was determined to be 1.5 by single rod glass electrode.

Executive summary:

In a pH test according OECD guideline 122 the pH of a 1% solution of diisobutyl phosphate in demineralized water was determined by a single rod glass electrode. 1g of the test item was weighed in a graduated cylinder and diluted with 100 ml demineralized water. The mean of three measurements after 1, 2 and 10 minutes resulted in a pH of 1.5.

 

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 122 (Determination of pH, Acidity and Alkalinity)

GLP compliance:

yes (incl. QA statement)

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Test material

Test material information

Constituent 1

Reference substance name:

Diisobutyl hydrogen phosphate

EC Number:

228-602-0

EC Name:

Diisobutyl hydrogen phosphate

Cas Number:

6303-30-6

Molecular formula:

C8H19O4P

IUPAC Name:

bis(2-methylpropoxy)phosphinic acid

Test material form:

liquid

Reagents

Reagent:

NaOH solution

Titration of acidity and alkalinity

Details on titrant used:

1N NaOH-solution

Results and discussion

Acidity or alkalinity

Key result

Acidity or alkalinity:

acidity

Value:

1.32

Any other information on results incl. tables

The acidity calculated as H2SO4 is 23.3 %. This is equal to a pH of 1.3

Applicant's summary and conclusion

Conclusions:

The acidity of diisobutylphosphate calculated as H2SO4 is 23.3 %, equal to a pH of 1.3. this confirms the measurments by glass rod electrode.

Executive summary:

The acidity of diisobutyl phosphate was determined in accordance to OECD Guideline 122 as the pH value by glass electrode is below 4.0. The titration was performed according to CIPAT MT 31: approx. 5 g of the test item were weighed in and titrated with 1N NaOH-solution using a potentiometric endpoint detection. During the titration the sample solution was murky but went clear. Two independent determinations were carried out. The acidity calculated as H₂SO₄ is 23.3 wt.-%, which corresponds to 1.32 pH.