Disodium 2-(2,4,5,7-tetraiodo-6-oxido-3-oxoxanthen-9-yl)benzoate

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard test guidelines

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))

GLP compliance:

no

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

The solutions of the test substance and reference substances were prepared in the mobile phase. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.

Chromatographic Conditions:
• HPLC Model No.: Agilent Technologies,1260 Infinity
• Flow Rate: 1.0ml/min
• Column: ZORBAX Eclipse Plus C18, 4.6×250mm, 5 µm
• Mobile phase : Methanol: water (55:45)
• Temperature : 25°C
• Detector: Diode Array Detector @210nm
• Injector: Autosampler
• Injector volume : 20µl
• Data Acquisition system: ChemStationOpen lab Control Panel
• Analysis time : 30min

Analytical monitoring:

no

Sample No.:

#1

Type:

log Koc

Value:

1.291 dimensionless

pH:

7.6

Temp.:

25 °C

Remarks on result:

other: The Log Koc value was determined to be 1.291± 0.051 at 25°C.

Details on results (HPLC method):

The Adsorption coefficient (KOC) on soil and on sewage sludge of the test chemical was determined to be 1.291± 0.051 at 25°C.

Observation table:

Test substance		K	Log k	Log Koc By Generalized Calibration Graph	Mean of LogKoc± S.D.
tR1	3.351	0.416	-0.380	1.255	1.291± 0.051
tR2	3.48	0.470	-0.327	1.328

Validity criteria fulfilled:

yes

Conclusions:

The Adsorption Coefficient of test substance was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 1.291± 0.051 at 25°C. Thus based on the result it is concluded that the test substance has a negligible sorption to soil and sediment and therefore has rapid migration potential to ground water.

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test chemical solution was prepared by accurately weighing 50mg of test chemical and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 7.681. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Urea, Benzamide, N-methylbenzamide, 4-Nitrobenzamide, N,N-dimethylbenzamide, 4-methylaniline(p-Tolouidine), 4-chloroaniline, N-methylaniline, Nitrobenzene, 2 - nitrophenol, phenanthrene, were chosen having Koc value range from 1.239 to 4.09. The Log Koc value of test chemical was determined to be 1.291± 0.051 dimensionless at 25°C. This log Koc value indicates that the substance has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test chemical solution was prepared by accurately weighing 50mg of test chemical and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 7.681. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Urea, Benzamide, N-methylbenzamide, 4-Nitrobenzamide, N,N-dimethylbenzamide, 4-methylaniline(p-Tolouidine), 4-chloroaniline, N-methylaniline, Nitrobenzene, 2 - nitrophenol, phenanthrene, were chosen having Koc value range from 1.239 to 4.09. The Log Koc value of test chemical was determined to be 1.291± 0.051 dimensionless at 25°C. This log Koc value indicates that the substance has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

19.54

Additional information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 for testing of Chemicals. The solutions of the test substance and reference substances were prepared in appropriate solvents. A test chemical solution was prepared by accurately weighing 50mg of test chemical and diluted with mobile phase up to 100ml. Thus, the test solution concentration was 500mg/l. The pH of test substance was 7.681. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k. The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor. The reference substances Urea, Benzamide, N-methylbenzamide, 4-Nitrobenzamide, N,N-dimethylbenzamide, 4-methylaniline(p-Tolouidine), 4-chloroaniline, N-methylaniline, Nitrobenzene, 2 - nitrophenol, phenanthrene, were chosen having Koc value range from 1.239 to 4.09. The Log Koc value of test chemical was determined to be 1.291± 0.051 dimensionless at 25°C. This log Koc value indicates that the substance has a negligible sorption to soil and sediment and therefore have rapid migration potential to ground water.