Salts of 9-[2-(ethoxycarbonyl)phenyl]-3,6-bis(ethylamino)-2,7-dimethylxanthenium chloride and 4-{[1-hydroxy-6-({[5-hydroxy-6-(phenyldiazo)-7-sulfonaphthalen-2-yl]carbamoyl}amino)-3-sulfonaphthalen-2-yl]diazo}benzoic acid (2:1)

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2008-10-16 to 2008-10-18

Reliability:

1 (reliable without restriction)

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2009

Materials and methods

Test guideline

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

Principles of method if other than guideline:

not applicable

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other: soil/sewage sludge (Estimation using HPLC)

Test material

Reference

Name:

Unnamed

Type:

Constituent

Details on test material:

not applicable

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
not applicable

Radiolabelling:

no

Study design

Test temperature:

25 °C

HPLC method

Details on study design: HPLC method:

HPLC system: Merck-Hitachi LaChrom HPLC system
Analytical column: LiChrospher 100 CN (5μm) 250x4 No.: 638212
Detector: UV at 254 nm and 530 nm Mobil Phase: Methanol : Water : Trifluoroacetic acid = = 60 : 40 : 0.04 Flow: 0.8 ml/min.
Injection volume: 10 µl
Temperature: 25 °C
Mobil Phase: Methanol : Water : Trifluoroacetic acid mixture with the ratio 60 : 40 : 0.04 (v/v)
Solution of the Test Item: 1.0 mg/ml F 213 Red in Methanol

Results and discussion

Adsorption coefficient

Adsorption coefficient 1

Type:

Koc

Value:

ca. 0.645

Adsorption coefficient 2

Type:

log Koc

Value:

> 5

Results: HPLC method

Details on results (HPLC method):

The adsorption coefficient Koc was determined based on a calibration curve using 8 reference items. In order to confirm the result obtained in this study for the log Koc value of DDT an additional measurement was performed subsequent to this study at a higher concentration rate. The capacity factors k’ were calculated from the dead time and retention times of the reference substances. The log k’ data of the reference substances were plotted against their log Koc values. F 213 Red eluted after all reference substances.

Any other information on results incl. tables

no remarks

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In the course of the adsorption/desorption study the adsorption coefficient (Koc) of F 213 Red was estimated, using high performance liquid chromatography. The test item eluted later than the reference substance with highest Koc (DDT). Therefore, the Koc of the test item is above the calibrated range. In conclusion, the estimated log Koc: > 5.0. The quality criteria were met, as values of log Koc derived from individual measurements fell within a range of 0.25 log units and the correlation coefficient R was >0.95.

Executive summary:

The log Koc was estimated at > 5.0.