Aluminium, 4,5-dihydro-5-oxo-1-(4-sulfophenyl)-4-[(4-sulfophenyl)azo]-1H-pyrazole-3-carboxylic acid complex

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Experimental test result performed using standard OECD test guidelines

Qualifier:

according to guideline

Guideline:

other: Adapted from IS: 2720 (Part 4)

Principles of method if other than guideline:

Reverse Phase High Performance Liquid Chromatography on Octadecyl-modified silica based stationary phase is used.
Partitioning on the column occurs in order of hydrophobicity when a suitable mobile phase is used. From relationship between the measured retention times and the adsorption coefficient on organic matter of reference substances, the sorption coefficient of the test substance is calculated.

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Specific details on test material used for the study:

- Name of test material (IUPAC name): aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate)
- Common name: FD&C Yellow No. 5 Aluminum Lake
- Molecular formula: C48H33AlN12O27S6
- Molecular weight: 495.4038 g/mol
-InChl:1S/C16H12N4O9S2.Al/c21-15-13(18-17-9-1-5-11(6-2-9)30(24,25)26)14(16(22)23)19-20(15)10-3-7-12(8-4-10)31(27,28)29;/h1-8,13H,(H,22,23)(H,24,25,26)(H,27,28,29);/b18-17+;
- Substance type: Organic
- Physical state: solid

Radiolabelling:

not specified

Test temperature:

25 deg.C

Details on study design: HPLC method:

PREPARATION PROCEDURE
Preparation of Reference substances:
Six reference substances, 2-nitrophenol, nitrobenzene, 4-nitrobenzamide, N, N-dimethylbenzamide, Nmethylbenzamide
and benzamide were chosen having Koc value ranging from 1.239 to 2.47 Individual solutions of these reference substances were prepared in methanol with concentrations of 500 mg/l.
Urea (at concentration of 500 mg/l) was used as an unretained compound for the determination of the “dead time” t0.
K=tR -t0
t0
where
k= capacity factor,
tR= retention time of test substance and reference substance.
t0=retention time of Urea.

Analytical monitoring:

yes

Details on sampling:

A test item solution was prepared by accurately weighing 3 mg of test item and diluted with methanol up to 10 ml. Thus, the test solution concentration was 300 mg/l. The pH of test substance was 6.71.

Details on test conditions:

Chromatographic Conditions:
HPLC Model No. : Agilent Technologies,1260 Infinity
Flow Rate : 1.0ml/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : Methanol: water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel

Key result

Sample No.:

#1

Type:

log Koc

Value:

0.704 dimensionless

Temp.:

25 °C

Remarks on result:

other: other details not available

Details on results (HPLC method):

HPLC PROCEDURE:
The solutions of the test substance and reference substances were prepared in solvent mentioned in 4.3. 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(Annex - 2).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.

Transformation products:

not specified

The Log K_ocof aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225 -21 -7 ) was determined to be 0.0740 dimensionless at 25°C.

Reference substance	Log koc	Rt1	Rt2	Rt3	Mean R± SD	K	Log K
Urea	NA	0.968	0.968	NA	0.968±0.0	0	0
2-nitrophenol	2.47	3.108	3.108	NA	3.108±0.0	2.21	0.3444
Nitobenzene	2.35	3.117	3.121	NA	3.119±0.0028	2.222	0.3467
4-nitrobenzamide	1.43	1.519	1.519	NA	1.519±0.0	0.569	-0.2449
N,N dimethylbenzamide	1.52	1.717	1.719	NA	1.718±0.014	0.774	-0.1113
N-methylbenzamide	1.31	1.472	1.47	NA	1.471±0.0014	0.519	-0.2848
Benzamide	1.239	1.333	1.334	NA	1.3335±0.0007	0.3775	-0.4231

Test substance aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate)		K	Log k (X axis)	Log Koc ( Y axis)  By Generalized calibration graph	Mean of Log Koc± S.D
tR1	0.766	-0.2087	-0.6805	0.7111	0.7040±0.01
tR2	0.77	-0.2045	-0.6892	0.6970

Validity criteria fulfilled:

not specified

Conclusions:

The Adsorption Coefficient of test substance aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No.12225-21-7)was determined as per the HPLC method. The Log Koc value obtained was 0.7040 dimensionless at 25°C.

Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225-21-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 2-nitrophenol, nitrobenzene, 4-nitrobenzamide, N, N-dimethylbenzamide, Nmethylbenzamide and benzamide were chosen having Koc value ranging from 1.239 to 2.4.

The Log Koc value of test chemical aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) was determined to be 0.7040 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225-21-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 2-nitrophenol, nitrobenzene, 4-nitrobenzamide, N, N-dimethylbenzamide, Nmethylbenzamide and benzamide were chosen having Koc value ranging from 1.239 to 2.4.

The Log Koc value of test chemical aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) was determined to be 0.7040 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:

5.06

Additional information

Experimental studies for target chemical aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225-21-7) and for its parent compound as read across chemical are summarized below for adsorption endpoint.

 

 In a key study the adsorption coefficient Koc in soil and in sewage sludge for target chemical aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225-21-7) was determined by the Reverse Phase High Performance Liquid Chromatographic method. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances were 2-nitrophenol, nitrobenzene, 4-nitrobenzamide, N, N-dimethylbenzamide, Nmethylbenzamide and benzamide were chosen having Koc value ranging from 1.239 to 2.4.

The Log Koc value of test chemical aluminum tris (4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) was determined to be 0.7040 dimensionless at 25°C. Based on the value of log Koc it is concluded that this test chemical has negligible sorption to soil and sediments and therefore has rapid migration potential to ground water.

 

Next study was supporting study done from U.P.B. Science Bulletin (Series B, Vol. 78, Iss. 1, 2016 P.137-148 ) in this study the Soil adsorption test was conducted for read across chemical tartrazine by using sorption floatation method. Initial concentration of read across chemical was 5-500 mg/L with pH range of 7-9 at temperature 20 deg C were selected to study tartrazine removal efficiency. The removal efficiency of chemical tartrazine was determined to be 9% using soil as adsorbent in sorption floatation technique.

 

Last study was also supporting study done from Afinidad 66, no. 544 (2009) for read across chemical in this studytThe capacity of a Romanian soil to retain Acid Yellow 23 from aqueous solution by sorption has been investigated.

The experiments were performed by using a natural soil sampled from the depth of 0-15 cm in the industrial area of the city of Iasi during the summer time (July 2008) that was previously dried and further screened to achieve soil particles size of above 2 mm, equilibration being carried-out with solution of CaCl2. For the equilibrium study, 50 ml Acid Yellow 23 of different concentrations were mixed with a dose of 12 g/L soil, the mixture being subjected to stirring at the room temperature as long it was needed to reach the equilibrium. The Freundlich, Langmuir and linear isotherm models were applied to describe the process and the parameters of these equations were calculated.

The sorption equilibrium revealed that the soil with particles higher than 2 mm may uptake 0.25 mg/g.

The sorption process is best represented by the Langmuir isotherm. The results reveal that the sorption of Acid Yellow 23 onto particles of soils follows a pseudo second order kinetics, suggesting that the chemisorption is the rate controlling mechanism.

The organic carbon normalized sorption coefficient KOC = 151.46 L/Kg. The very low value of KOC shows that the dye tend to remain in solution indicating also its very high mobility, since it is considered that sorption coefficients less than 500 indicate a considerable potential for losses through leaching. The low value of the organic carbon normalized sorption coefficient KOC suggests a high potential of leaching that could result in contamination of the groundwater.

 

 By considering key study mentioned avove it is concluded that test chemical aluminum tris(4-{[3-carboxy-5-oxo-1-(4-sulfophenyl)-4,5-dihydro-1H-pyrazol-4-yl]diazenyl}benzenesulfonate) (CAS No. 12225-21-7) negligible sorption to soil and sediments and therefore has rapid migration potential to ground water and other both the studies corroborate this result.

[LogKoc: 0.704]