Fatty acids, tallow, compds. with triethanolamine

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 November 2015 to 6 September 2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

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

Radiolabelling:

no

Test temperature:

The test temperature was 25 °C

Details on study design: HPLC method:

HPLC EQUIPMENT AND EXPERIMENTAL CONDITIONS
Column: Zorbax CN 250 × 4.6 mm with the corresponding guard column
Mobile Phase: Methanol (55 %) and water (45 %), isocratic
Temperature: 25 °C
Flowrate: 1 mL/min
Injection volume: 25 µL
Detection: 210 nm
Run time: 60 minutes (formamide and acetanilide) to 60 minutes (test substance, DDT and mixed standard)

Three standards; formamide (for void volume), acetanilide (the lowest standard, log Koc of 1.25) and DDT (the highest standard, log Koc of 5.63) were used. Two identical runs were performed.

Due to the characteristics of the test substance a value for the adsorption coefficient could not be determined by experimental means.

Key result

Type:

log Koc

Value:

>= 2.409 - <= 13.021 dimensionless

Remarks on result:

other: KOCWIN-MCI method

Key result

Type:

log Koc

Value:

>= 2.416 - <= 12.211 dimensionless

Remarks on result:

other: LKOW method

Details on results (HPLC method):

ESTIMATION OF THE ADSORPTION COEFFICIENT
Experimental Procedures
Consideration of the chemical structure and physical properties of the test material would lead to difficulties in determining a reliable adsorption coefficient.

A feasibility study was conducted to assess whether or not the HPLC simulation method could be used, as the test material exhibited a strong UV absorbance, albeit at 210 nm. A weak broad peak was observed either between that of formamide (the void marker) and acetanilide or before the formamide peak. This was not thought to be representative of the test material as it is a mixture and a quoted purity of 70 %. The representative chemical structure of the test material provided by the sponsor also indicate low UV chromophore group further supporting that HPLC-UV may not be suitable.

To confirm if the test substance was bound to the column, or not retained, the column was cleaned by first flushing with methanol for 1 hour followed by THF for 1 hour and then water for 1 hour. The system was then left equilibrating overnight with the mobile phase (55 % methanol:45 % water). With the initial methanol wash there was a large amount of contamination driven off. Nothing was recorded for the THF or water washes.

For the test material, the initial peak before the void marker was present but it also gave a number of peaks at 68 to 70 mins.

The peaks were further investigated to ascertain whether the peaks for the test material were retained on the frit or the column. This investigation revealed that the peaks at 68 and 70 mins were residual analytes that were not removed by the initial cleaning regime, as all subsequent injections of EXP150138 were clean. Under these conditions it can be assumed that the test material was not retained on the column.

It was concluded that on this basis the adsorption coefficient could not be estimated practically. Based on this it was decided calculate adsorption coefficient values using the Estimation Program Interface EPI ver. 4.1.

Calculated values
Calculated values for the log Koc were determined for each of the specified constituents of the test substance stated in information provided by the Sponsor.
The EPI ver 4.1 software used two different methods for calculating the adsorption coefficient, the KOCWIN-MCI and LKOW methods. The calculated values for log Koc from these two methods were as follows:

- KOCWIN-MCI calculated values ranged from 3.0072 for (E)-2-(nonenyl)butane-1,4-dioic acid to 4.4604 for (E)-2-(pentadecenyl)butane-1,4-dioic acid.
- The LKOW calculated values ranged from 1.9755 for (E)-2-(nonenyl)butane-1,4-dioic acid to 3.5243 for (E)-2-(pentadecenyl)butane-1,4-dioic acid.

To test whether or not the test material was retained on the column, the following gradient was applied:

Time (minutes)	Methanol (%)	Water (%)
0	55	45
60	55	45
70	100	0
130	100	0
140	55	45
150	55	45

Calculated Values for Adsorption Coefficient

Common name	log Koc
R = C14:0	2.4095 (KOCWIN-MCI) 2.4161 (LKOW)
R = C16:0	2.9308 (KOCWIN-MCI) 2.9582 (LKOW)
R = C16:1	2.9308 (KOCWIN-MCI) 2.8420 (LKOW)
R = C18:0	3.4521 (KOCWIN-MCI) 3.5058 (LKOW)
R = C18:1	3.4521 (KOCWIN-MCI) 3.3841(LKOW)
R = C18:2	3.4521 (KOCWIN-MCI) 3.2679 (LKOW)
R = C18:3	3.4521 (KOCWIN-MCI) 3.1462 (LKOW
R1= C14:0 R2 = C18:0	7.3275 (KOCWIN-MCI) 7.4414 (LKOW)
R1 = C14:0 R2 = C18:3	7.3275 (KOCWIN-MCI) 7.0819 (LKOW
R1= C16:1 R2=C18:3	7.8488 (KOCWIN-MCI) 7.5078 (LKOW)
R1 = C14:0 R2 = C16:0 R3 = C18:0	13.0211 (KOCWINMCI) 12.2115 (LKOW)
R1 = C14:0 R2 = C16:1 R3 = C18:1	13.0211 (KOCWINMCI) 11.9737 (LKOW)
R1 = C14:0 R2 = C16:1 R3 = C18:3	13.0211 (KOCWINMCI) 11.7358 (LKOW)

Validity criteria fulfilled:

yes

Conclusions:

The calculated estimation of the adsorption coefficient (Log Koc) ranged from 2.4095 to 13.0211(KOCWIN-MCI method) and 2.4161 to 12.2115 (LKOW method).

Executive summary:

The adsorption coefficient of the test material was investigated in a study which was performed under GLP conditions and in accordance with the standardised guideline OECD 121 (Calculation).

Consideration of the chemical structure and physical properties of the test material would lead to difficulties in determining a reliable adsorption coefficient therefore a feasibility study was conducted to assess whether or not the HPLC simulation method could be used. Due to the characteristics of the test substance a value for the adsorption coefficient could not be determined by experimental means. It was therefore decided that estimated values would be calculated using appropriate software (Estimation Program Interface EPI ver. 4.1.)

The calculated estimation of the adsorption coefficient (Log Koc) ranged from 2.4095 to 13.0211(KOCWIN-MCI method) and 2.4161 to 12.2115 (LKOW method).

Reference 2

Endpoint:

adsorption / desorption: screening

Remarks:

Further information on adsorption/desorption

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Description of key information

The calculated estimation of the adsorption coefficient (Log Koc) ranged from 2.4095 to 13.0211(KOCWIN-MCI method) and 2.4161 to 12.2115 (LKOW method).

Additional information

The adsorption coefficient of the test material was investigated in a study which was performed under GLP conditions and in accordance with the standardised guideline OECD 121 (Calculation). The study was assigned a reliability score of 2 in accordance with the criteria for assessing data quality set forth by Klimisch et al. (1997).

Consideration of the chemical structure and physical properties of the test material would lead to difficulties in determining a reliable adsorption coefficient therefore a feasibility study was conducted to assess whether or not the HPLC simulation method could be used. Due to the characteristics of the test substance a value for the adsorption coefficient could not be determined by experimental means. It was therefore decided that estimated values would be calculated using appropriate software (Estimation Program Interface EPI ver. 4.1.)

The calculated estimation of the adsorption coefficient (Log Koc) ranged from 2.4095 to 13.0211(KOCWIN-MCI method) and 2.4161 to 12.2115 (LKOW method).