PIGMENT ROT 5021 A

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004-11-02 to 2005-01-03

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant; Guideline Study (OECD 121)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

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))

Deviations:

no

Test guideline 2

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:

soil/sewage sludge

Test material

Test material information

Constituent 1

Radiolabelling:

no

Study design

Test temperature:

25 °C

HPLC method

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Varian autosampler 9100; Varian pump 9010; Varian detector 9050
- Type, material and dimension of analytical (guard) column: LiChrospher 100 CN, part, size 5 µm, 250 mm x 4 mm;
- Detection system: Varian detector 9050;

MOBILE PHASES
- Type: Acetonltrile and water (55:45; v/v); pH 6.8
- pH: pH 6.8
- Solutes for dissolving test and reference substances: acetonitrile;

REFERENCE SUBSTANCES
- Identity: Sodium nitrate; Acetanilide; Isoproturon; Linuron; Pyrazophos; Diclofop-methyl; 2,4-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 20 µL;
- Quantity of reference substances:20 mL;


REPETITIONS
- Number of determinations: 3 test runs; 6 reference runs;

EVALUATION
- Calculation of capacity factors k': the capacity factor (k') is calculated from the retention time of the reference items, the test item (tf) and an unretarded item (to): k' = t r - to/to, where tr = Retention time of the test item or reference Item, to = Time a non-sorbed chemical needs to pass the column (dead-time, sodium nitrate solution);
- Determination of the log Koc value: The adsorption coefficient (Koc) is deduced from the capacity factor (k') using a calibration plot of log k' versus log Koc of the selected reference item:
k' = tr - to / to
tr = HPLC retention time of test or reference items [min]
to = HPLC dead time [min] (measurement of the retention time of sodium nitrate)

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

log Koc

Value:

< 1.25

Temp.:

25 °C

Adsorption coefficient 2

Type:

Koc

Value:

< 18

Temp.:

25 °C

Results: HPLC method

Details on results (HPLC method):

- Retention times of reference substances used for calibration: (6 runs):
Sodium nitrate: 1.15; 1.162 (2 runs);
Acetanilide: average retention time [min]: 2.92;
Isoproturon: average retention time [min]: 3.41;
Linuron: average retention time [min]: 3.86;
Pyrazophos: average retention time [min]: 4.42;
Diclofop-methyl: average retention time [min]: 5.17;
2,4 -DDT: average retention time [min]: 6.53;

- Average retention data for test substance ( 3 runs):
1st Peak: 1.111; 1.122; 1.124;
2nd Peak: 1.385; 1.393; 1.396;
3rd Peak: 1.584; 1.579; 1.572;
4th Peak: 1.712; 1.712; 1.712;

Any other information on results incl. tables

The log of the adsorption coefficient of the test item was determined to be < 1.25. This value indicates that the test item will not be adsorbed by organic carbon in soil. The test item is of very high mobility.