Fatty acids, C16-18 (even numbered), reaction products with diethylene triamine, di-Me sulfate quaternized

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:

08.07.2010 to 19.07.2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study according to EC C.19 (OECD 121)

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))

Version / remarks:

(2001)

Deviations:

yes

Remarks:

In deviation from guideline, the test item solution was repeated by injection 10 days after the measurement of the reference item solutions.

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

(2001)

Principles of method if other than guideline:

In deviation from guideline, the test item solution was repeated by injection 10 days after the measurement of the reference item solutions.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Merck-Hitachi autosampler L-7450, Merck-Hitachi pump L-6200, Sedex ELSD detector 85 (Channel A), Jones column oven 7990
- Type: HPLC with UV/VIS detector
- Type, material and dimension of analytical (guard) column: LiChrospher 100 CN, particle size 5 µm, 250 mm x 4 mm
- Detection system: UV/VIS

MOBILE PHASES
- Type: water/methanol: 45:55 v/v
- Experiments with additives carried out on separate columns: no
- pH: 5.76
- Solutes for dissolving test and reference substances: methanol

DETERMINATION OF DEAD TIME
- Method: by means of homologous series / by inert substances which are not retained by the column: sodium nitrate solution was used for the determination of the dead time of the HPLC system

REFERENCE SUBSTANCES
- Identity: acetanilide, isoproturon, linuron, pyrazophos, dicyclofop-methyl, and 2,4-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 0.4 µg/µL
- Quantity of reference substances: acetanilide: 0.1134 µg/µL , isoproturon: 0.123 µg/µL , linuron: 0.0984 µg/µL, pyrazophos: 0.1044 µg/µL, dicyclofop-methyl: 0.1019 µg/µL, and 2,4-DDT: 0.0949 µg/µL
- Intervals of calibration: not reported

REPETITIONS
- Number of determinations: test item: 3 replicates; reference items: 6 replicates, sodium nitrate (dead time determination): 3 replicates

EVALUATION
- Calculation of capacity factors k': the capacity factor k' was calculated according to the equation: k'=tr-to/to (with tr=retention time of the test item or reference item, to=dead time)
- Calculation of retention times: not applicable
- Determination of the log Koc value: the adsorption coefficient (Koc) was deduced from the capacity factor k' using a calibration plot of log k' versus log Koc of the selected reference items

Type:

log Koc

Value:

> 5.63

Temp.:

25 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration: acetanilide: 2.98 min, isoproturon: 3.32 min, linuron: 3.72 min, pyrazophos: 4.38 min, dicyclofop-methyl: 4.71 min, and 2,4-DDT: 6.15 min
- Details of fitted regression line (log k' vs. log Koc): slope: 0.106; y-axis intercept: -0.054; coefficient of regression: 0.999
- Average retention data for test substance: not applicable as the test item could not be eluted from the column

Validity criteria fulfilled:

yes

Conclusions:

The soil sorption coefficient of the test item was estimated to be > 427,000 (log Koc>5.63). This value would indicate that the test substance will be adsorbed by organic carbon in soil. Based on the results, the test item can be regarded as immobile in soil. According to the statement in the guideline, however, the method may not work for surface-active substances and the results (test substance was not eluted from the column) confirm this statement

Executive summary:

In a study conducted according to OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC; 2001)) and EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC; 2001)) the soil sorption coefficient Koc was determined to be >427,000 (log Koc>5.63. This value would indicate that the test substance will be adsorbed by organic carbon in soil. Based on the results, the test item can be regarded as immobile in soil. According to the statement in the guideline, however, the method may not work for surface-active substances and the results (test substance was not eluted from the column) confirm this statement

Description of key information

Partially unsaturated IQAC, DMS quaternised will strongly interact with soils, sediment and suspended matter in natural environment. It is technically not feasible to determine a concrete soil sorption coefficient

Key value for chemical safety assessment

Koc at 20 °C:

427 000

Additional information

In a study according the EC C.19 guideline (OECD 121) the adsorption coefficient Koc of Partially unsaturated IQAC, DMS quaternised was studied. It was found that the test item strongly interacted with the analytical column. The reference substance 2,4 -DDT was detected and had a retention time of 6.15 minutes. Based on the results obtained it was concluded that the test substance has a Koc value of higher than the reference substance 2,4-DDT. It corresponds with Koc and log Koc value for the test substance of>427,000 (log Koc>5.63, respectively. A concrete soil sorption coefficient could not be determined as the test item was not eluted from the column. In the guideline, however, it is stated that the method may not work for surface active substances and the results confirm this. Therefore, this study is not appropriate to determine the soil sorption coefficient.

[LogKoc: 5.63]