Phosphoric acid, C14-15-branched and linear alkyl esters, potassium salts

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other:

Specific details on test material used for the study:

Name: Phosphoric acid, C14-15 branched and linear alkyl esters, potassium salts
CAS No.: 1893414-79-3
Physical state: white solid at 20 °C
Batch No.: PU61810016
Re-certification date of batch: 09 March 2018
Purity: 100 % (UVCB, lyophilized solid, water content 0.85 % (w/w))
Stability: stable under test conditions
Storage condition of test material: Room temperature, protected from light

Radiolabelling:

no

Details on study design: HPLC method:

The aim of this study was the determination of the adsorption coefficient of the test item on soil and on sewage sludge (Koc) by high performance liquid chromatography (HPLC) method according to EC method C.19 (440/2008) and OECD guideline 121. The analysis was performed on an analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties. A moderately polar stationary phase based on a silica matrix was used (EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm). A mixture of 55 % methanol / 45 % ultra-pure water was used as mobile phase and the column temperature was 25 °C ± 1 °C.

The dead time t0 was measured by using the unretained compound sodium nitrate. Sodium nitrate was included in the used reference mix. 6 reference compounds were used by injection of a reference mix. The reference mix was injected two times before and two times after the test item sample. The retention times were determined. The retention time of the test item was determined 4 times.Two measurements (made under identical conditions and using the same set of reference items) were performed.

Analytical monitoring:

yes

Details on sampling:

A sample was prepared by giving about 10 mg test item into a centrifuge tube. 10 mL of methanol / ultra-pure water (55/45 % v/v) was added and the mixture was shaken for 3 hours and 20 minutes on a flat bed shaker.Finally the sample was centrifuged for 10 minutes at 400 rpm. A sample of the clear supernatant was the taken and used for analysis. The reference mix was prepared in methanol.

Matrix no.:

#1

Matrix type:

other: EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm

Key result

Sample No.:

#1

Type:

log Koc

Remarks:

mean of two runs

Value:

< 1.5 dimensionless

Temp.:

25 °C

Matrix:

column: EC 150/4.6 Nucleodur 100-5 CN-RP 150 x 4.6 mm; 5 µm

Remarks on result:

other: log Koc is below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log Koc of the lowest reference standard phenol is 1.32

Key result

Sample No.:

#1

Phase system:

soil-water

Type:

log Kp

Value:

1.45

Remarks on result:

other: Peak start: below determination limit of method and below lowest used reference standard (phenol). Peak end: below determination limit of method, but within calibration range.

Transformation products:

not measured

Validity criteria fulfilled:

yes

Remarks:

The log Koc of two measurements made under identical conditions and using the same set of reference items fall within a range of ± 0.25 log units. The requirements of OECD guideline 121 concerning the quality criteria are fulfilled.

Conclusions:

The log Koc of the test item is below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log Koc of the lowest reference standard phenol is 1.32.

Executive summary:

The aim of this study was the determination of the adsorption coefficient of the test item on soil and on sewage sludge (Koc) by high performance liquid chromatography (HPLC) method according to EC method C.19 (440/2008) and OECD guideline 121. The log Koc is below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log Koc of the lowest reference standard phenol is 1.32.

Description of key information

The log Koc of the test item is below determination limit of the method (log Koc = 1.5 according to OECD 121 and EC method C.19) but within the calibration range (log Koc of the lowest reference standard phenol is 1.32.

Key value for chemical safety assessment

Koc at 20 °C:

0.18

Additional information

[LogKoc: 1.5]